cane production manual
TRANSCRIPT
ADVANCES IN SUGARCANE PRODUCTION TECHNOLOGY
N.BALASUNDARAMR.THIAGARAJAN
RAJULA CHANDRAN
2003
SUGARCANE BREEDING INSTITUTE(Indian council of Agricultural Research)
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COIMBATORE 641 007INDIA
CONTENTS
No. ParticularsPage No.
1
Preface
National sugarcane varietal improvement programme
N.Balasundaram
1
2 Sugarcane varieties suitable for peninsular zone
K.V.Bhagyalakshmi and T.V.Sreenivasan
13
3 Breeding methodologies and seed nursery programme
R.Nagarajan
23
4 Breeding for red rot resistance
U.S.Natarajan
26
5 Quality seed production in sugarcane 39
6 Micropropagation of sugarcane varieties for quality seed production
N.C.Jalaja
42
7 Biotechnology in sugarcane improvement
N.V.Nair
47
8 Cane agronomy for wide row spacing
P.Gopalasundaram and C.Kailasam
61
9 Improving sugarcane ratoon productivity
B.Sundara
67
10 Cost management in sugarcane production systems
B.Sundara
71
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Management of problem soils
P.Rakkiyappan
80
12 Biofertilizers for sugarcane 88
2
K.Hari
13 Post harvest deterioration of cane and sugar losses
S.Asokan
96
14 Moisture stress and its management in sugarcane
S.Venkataramana and T.Ramanujam
111
15 Flowering in sugarcane and methods of control
P.N.Gururaja Rao
117
16 New implements in sugarcane cultivation
S.Rajamohan
124
17 Sugarcane diseases and their management
P.Padmanaban and N.Prakasam
132
18 Integrated pest management in sugarcane
S.Easwaramoorthy
139
19 Extension and technological package for sugarcane improvement
R.Thiagarajan and Rajula Chandran
145
20 Participatory Extension approach for sugarcane development
R.Thiagarajan and Rajula Chandran
161
21 Computer applications in sugarcane production
S.Shunmugasundaram
168
22 Package of practices for sugarcane cultivation
Rajula Chandran and R.Thiagarajan
179
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Copy right © by Sugarcane Breeding Institute, Coimbatore All rights reserved2003
Published by
N.BalasundaramDirectorSugarcane Breeding InstituteCoimbatore 641 007
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NATIONAL SUGARCANE VARIETAL IMPROVEMENT PROGRAMME
N. BALASUNDARAM
Sugarcane is an important crop in the country, economically and sociologically. It is
the second largest agroindustry next to textiles. Sugarcane is cultivated in around 4.28 million
hectares, producing 299 million tonnes of cane at approximately 71 tonnes per hectare. Out
of this, 60 percent goes to the white sugar industry and the rest is utilized for 'gur',
'Khandsari', seed, chewing etc. The country produces more than18 million tonnes of sugar
through more than 423 sugar mills. Nearly 35 million persons are engaged in the production
of cane and sugar. Though India is the highest producer of sugar in the world at present, the
demand for sugar for internal consumption is growing due to increased per capita
consumption and the increase in population size and the need to export for earning foreign
exchange. It is estimated to reach 45 million tonnes by the year 2025.
The increased requirement of sugar has to be met mostly through enhanced
production per unit area/unit time, since there is no further possibility of increasing the area
under sugarcane due to competition from other crops. The theoretical maximum yield of
cane has been estimated as 470 metric tonnes of fresh total biomass per hectare per year on
the basis of the efficiency (3.6%) of use of total incident solar radiation. World's highest
recorded yield was reported to be 255 metric tonnes per hectare (Ham, 1970). Since then,
higher yields have been reported within the country to the tune of 340 metric tonnes per
hectare in Gujarat (Hapse, 2001-personal communication). Compared to these yield levels,
the national average is around 71 tonnes, the average yields in various states ranging from 46
tonnes in Bihar to 113 tonnes in Tamilnadu. Thus there is ample scope for improvement of
cane and sugar productivity in the country.
Sugarcane is known to be under cultivation in India from the Vedic times or even
earlier. India is considered to be one of the centres of diversity for Saccharum and allied
genera. The genus Saccharum falls under the family Gramineae and is constituted by the
following species:
S.officinarum L., S.barberi Jesw., S.sinense Roxb., S.robustum, Brandes and Jeswiet
ex Grassl, S.spontaneum L. and S.edule Hassk.
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The other related genera, which are closely related to Saccharum and are freely
crossable with it, are Erianthus, Narenga, Sclerostachya and Miscanthus. Sugarcane
Breeding Institute, Coimbatore is one of the two world repositories of sugarcane germplasm,
the other being the sub-tropical Horticulture Research Station of USDA at Miami, Florida,
USA. Bulk of the Indian Sugarcane Germplasm collection is maintained at the Kannur
Research Centre and the S.spontaneum and Erianthus spp. collection is maintained at
Coimbatore.
Even though sugarcane cultivation has been practiced from ancient times, it was
dependent on the natural variation generated by spontaneous mutations and products of
natural hybridization. The varieties in cultivation were variants of S.officinarum in the
tropics and S.barberi and S.sinense in North India and in southern China respectively. It was
recognized in 1858 that sugarcane true seeds were viable and were capable of giving rise to
seedlings and mature plants, but it took another three decades to start raising seedlings of
sugarcane on experimental basis. Active breeding programmes were initiated in Java,
Barbados, British Guyana, Reunion, Queensland and Mauritius during the 1890s. In India,
Hawaii and other parts of the world breeding programmes were started during the early part
of the twentieth century. Initially the work on hybridization and selection were restricted to
intercrossing the S.officinarum clones (both typical and atypical) and limited success was
obtained through intervarietal crosses, but improved vigour and resistance to many diseases
became possible only after interspecific crosses were attempted. Kobus in 1897 crossed a
S.barberi clone "Chunnee” with S.officinarum and by backcrossing the progeny to the
officinarum for dilution of the traits from the barberi clone obtained 'Sereh' disease resistant
varieties. This led to increased interest in interspecific hybrids. In India, Barber in 1912
crossed 'Vellai', a S.officinarum clone with a local form of S.spontaneum (2n = 64) and
obtained several promising clones starting with Co 205, which became the first interspecific
hybrid to become a commercial success in India. Subsequently clones of S.barberi were
nobilized to produce clones, which were intercrossed to S.spontaneum clones. Some of these
early trispecific hybrids became commercially successful in sub-tropics and in several other
countries as well.
Breeding strategies may differ depending upon the nature of basic materials that are to
be involved in crossing. When Saccharum, related genera or the wild species of Saccharum
are to be utilized, the breeding strategy becomes a long-term effort. In the case of
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intervarietal crossing on the other hand, the breeding strategy is of short-term nature. The
breeding procedures in the former might vary based on the specific objective of utilizing a
particular genus/species as well as on the genetic nature of the progenies produced initially in
different intergeneric/interspecific families. In the latter category, however, the breeding and
testing procedures are almost uniform irrespective of the nature of parents involved. The
present discussion confines essentially to breeding methodologies as applicable to
intervarietal hybridization.
Choice of parents
One of the frequently used procedures is to choose parents that complement each
other for different agronomic traits. However, the purpose would be better served when
importance is given to traits with higher coefficients of genetic determination. In addition,
parents that are known for higher general combining ability should be given preference. The
degree of ancestral relationship (coefficient of co ancestry) should form the basis for deciding
the cross combinations.
Establishment of a breeding nursery
The breeding nursery should have as large a collection of genotypes as can be
assembled to maximize the level of genetic variability available to the breeder and to provide
reservoirs of alleles that may prove valuable in the event of crisis breeding. The more
advanced breeding programmes which have undergone several generations of variety
improvement have generally allocated space to foreign commercial varieties and to various
Saccharum species and related genera.
The choice of parents to be used in crosses is one of the most important decisions to
be made by the sugarcane breeder. Choice will be determined by short and long term goals,
by available materials, by the flowering and breeding behaviour of parents in specific cross
combinations and by the amount of data available on any parent or cross combinations.
The end product of most breeding programmes around the world is the development
of high yielding, disease resistance crop varieties. However, many breeding programmes
have as an intermediate step the development of source populations. Source populations
generally emphasize specific traits, which the breeder believes to be associated with yield
potential. Some source populations are developed by incorporating desired genes from
unadapted germplasm sources through several cycles of backcrossing onto an adopted
commercial genetic background. Source populations may also originate by screening only
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improved adopted parents for specific traits of interest, individually or in combination, while
largely ignoring all other traits.
Floral Biology
Sugarcane is a cross-pollinated plant, which depends on wind for cross pollination
under natural conditions. Sugarcane inflorescence consists of 30 - 50 thousand spikelets,
which are bisexual. At each node of the rachis, two spikelets are borne-one sessile and the
other pedicellate and both the spikelets do not flower on the same day. The flowers at the top
open first and the flowers at the lower inflorescence branches open later, the interval being 7-
10 days. The individual spikelets are protogynous. These factors increase the chances of
cross-pollination.
Crossing Techniques
Marcotting
The technique of marcotting was devised by Sugarcane Breeding Institute and is now
practiced in many areas. In this technique a plastic sleeve is secured about 5-10 nodes above
the base of the stalk, filled with a growth medium so that three or four nodes are covered, and
then wetted to ensure rooting. The stalk is cut below the rooted nodes and brought to the
crossing area.
Potted plants
For clones and species not amenable to the sulfurous acid technique or marcotting,
clones are grown in small containers that can be readily manipulated for crossing.
Saccharum spontaneum and genera related to Saccharum are candidates for this type of
treatment.
Crossing Procedures
Biparental crosses
Biparental crosses are defined as the crossing of two known parents and are probably
the most widely used by sugarcane workers. In the proven cross system, two parents of
known breeding value are crossed. To avoid outcrossing, the panicle of the female parent is
protected with a cloth bag supported by a lantern or a frame made of bamboo or aluminium.
Area cross
The area cross is a modification of biparental crosses in that several male sterile
clones can be pollinated by one male, which leads to greater efficiency in the crossing
system. This can be done either by placing the crosses in lanterns or in isolated areas
recognizing that if the crosses are placed near flowering sugarcane fields, some pollen
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contamination can occur. In setting up biparental or area cross, one should be careful to
remove all portions of the inflorescence where the spikelets have already opened.
Melting pot
This refers to a system of poly cross technique. A number of male fertile panicles of
proven parents are put around a diverse set of female parents (male sterile or low pollen
fertility) and the seed collected from the female parents. In this system only the female
parent of the resulting progeny can be known with certainty.
Pollen preservation
Because of the difficulties associated with differential timing of flowering among
certain desired parents, considerable effort has been made to study the feasibility of long term
pollen preservation. It is possible to preserve the pollen at sub-zero temperature and very low
relative humidity, till it is needed for pollination.
Flowering, hybridization, seedling raising and evaluation
Synchrony of flowering is a major aspect that decides the choice of parents. With
substantial levels of genetic variability available within early, mid and late flowerers, this
serves the purpose well. However, in certain cases where there is need to involve parents
which do not synchronize, photoperiodic treatment is resorted to.
Clones with 0 to 30% pollen fertility (anthers generally do not dehisce when pollen
fertility is low) are chosen as females and those with a pollen fertility of 60 % or more are
chosen as males. Clones in the intermediate range (30-60% pollen fertility) are used either as
female or male, if such clones are worthy of use as parents. Self-incompatibility is of
frequent occurrence in sugarcane that influences choice of parents. Highly pollen fertile
clones if they are self-incompatible (e.g. Co 62198) can be used as safe female parents in
addition to being used as male parents.
Sugarcane is a short day plant and is sensitive to photoperiodic simulation and
normally flowers during the months of October - December in the Northern Hemisphere
(India, North America etc.) and during April - June in the Southern Hemisphere (Australia,
South America etc.) Along the Equatorial plane, sugarcane flowers all through the year if
sufficient growth had been attained. The inflorescence called as tassel, arrow etc. in various
countries consists of 40 to 50 thousand spikelets, which are bisexual and protogynous. But
since the inflorescence takes about 7 to 10 days to complete flowering in acropetal
succession, there is considerable overlap between the flowerings in different portions of the
arrow, which makes selfing a possibility. Clones with less than 20% pollen fertility are
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generally used as pistil parents. The female arrows are enclosed in pollen proof cloth bags
supported by wooden or aluminum cages generally called lanterns. The floral branches of the
male inflorescence are collected around 5 A.M and the anthers are made to dehisce in
advance of natural dehiscence by placing them under strong light to provide a higher
temperature and a lower humidity to hasten the dehiscence. The dehisced pollen is dusted on
the female arrows for 7 to 10 days and the seed maturation period required is about 30 days.
Seed set in sugarcane is generally low, usually in the range of 0 -40%. This leads to a
great variation in the seedling density in the nursery benches leading to differential vigour of
the seedlings, which is inversely proportional to the density of the seedlings per unit area.
The sugarcane seed loses viability within 60-90 days of collection, if stored under room
temperature. When stored under low temperature (-20 to -80oC) in moisture proof
polyethylene or laminated aluminum foil pouches with the addition of silica gel or calcium
chloride as an insurance against power failure, the seed can be stored up to 10 years or more.
The seeds germinate on any suitable medium if the temperature and humidity is above the
required minimum levels of 20oC and 60% RH. The seedlings are generally transplanted to
polybags when 30-45 days old and subsequently to the field.
The seedlings are transplanted to the field when around 90 days old with a spacing of
around 60cm within rows and 85cm between rows. The seedlings are screened for yield and
quality components at the age of 10 to 12 months after transplanting, mainly to reject for
undesirable traits such as very thin canes, heavy leaf sheath spines, natural incidence of
diseases, narrow leaves, damage due to insect pests and other cane characteristics. The extent
of environmental variation at this stage is high and the intensity of selection at this stage is
around 30%. The selections are multiplied till the next planting season to build up sufficient
material for laying out a one-row trial.
Selection methodologies and response to selection
Of the three methods of selection viz., family selection, individual selection and
family selection followed by individual selection, the third system has been generally found
to give higher realization of selectable types.
In the initial stages, when the seedlings are mostly in small unreplicated plots, the
extent of the environment component in cane yield and its components is relatively high.
Hence selection is generally liberal (25 to 30%) and is based on the measurement of the
components of yield rather than on the yield per se. Only in subsequent stages when the plot
sizes are sufficiently large to reduce error variance, selection is based on actual yield of cane.
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Clonal testing procedures
First clonal trial or Pre-final clonal trial
First clonal trial or Pre-final clonal trial is laid out in Augmented RCBD with a plot
size of one 6 metre row with approximately 300 entries. The entries and standards are
screened for the yield and quality components at 10 and 12 months after planting. Since the
environmental variation is still high, mild selection is made for sucrose % juice and cane
yield components. Rejections are made for undesirable traits such as leaf sheath spines, large
bud size, splits or growth cracks, tendency to lodge, heavy and early flowering, very thin
stalks, natural incidence of diseases such as smut, GSD, heavy incidence of SCMV etc. and
insect pests such as top borer etc. Approximately 20% of the entries are selected and
multiplied.
Final clonal Trial or Pre-zonal trial
Selections from the prefinal clonal trial and selections from various other breeding
and genetic experiments are assembled and are evaluated in five locations namely,
Coimbatore (Central Peninsular), Jamkhandi (Upper Peninsular), Kovvur (East Coast),
Motipur (North Central) and Karnal (NorthWestern). The trials are taken up after one or two
years of multiplication of the entries received. The trials are laid out in RCBD or in
augmented RCBD depending upon the number of entries. Local commercial standards are
used as checks. The plot size is 4 rows of 6 metres with a row spacing of around 0.85 metres.
The entries are simultaneously screened for the major diseases namely smut and local races
of red rot through artificial inoculation, and scored for natural incidence of SCMV, GSD and
for infestation of insect pests. Entries possessing resistance/tolerance to major diseases and
pests and recording good yield and juice quality compared to standards with other desirable
cane characteristics are selected. The selection intensity at this stage is around 10%.
Zonal Varietal trials
Selections from the PZVT stage are multiplied for one year for entry into ZVT. The
entries for ZVT are discussed at the Annual AICRP Workshops and the entries contributed by
Sugarcane Breeding Institute, Indian Institute of Sugarcane Research and various State
Agricultural Universities are assembled at the concerned Zonal Centres and redistributed to
the testing centres within the zone, which may vary from 5 to 10. The trials are laid out in
RCBD with plot sizes of approximately 8 metres by 8 metres and the trial is conducted for
two plant crops and one ratoon crop. Simultaneously the entries are tested again for the
major diseases and insect pests. After the trials are concluded the entries are selected based
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on their performance across locations and are placed for approval before the State Varietal
Release Committees for release within the State and before the Central Varietal Release
Committee for release across States.
Normally the above process takes approximately 8 to 12 years from crossing to
release and another five years to spread and occupy considerable area due to the low
multiplication rate of sugarcane (1:10) and efforts are being made to multiply breeder seed
through meristem culture to facilitate the spread of a promising variety in a shorter period.
Breeding for wider and local adaptation
It is known that there are substantial levels of G x E interaction for cane yield and
their components. Cane quality is by and large free from G x E interaction, although a
variety behaves differently in different environments, in a more predictable way.
Since a very high level of genetic improvement for cane productivity has been
achieved, high yielding varieties with wider adaptation are hard to come by. Greater
emphasis is being given to location specific varieties to capitalize on their inherent genetic
potential. At the same time, care should be taken not to loose the limited chances of
obtaining a variety with wider adaptation. The current emphasis on utilizing a broad genetic
base and testing the promising clones developed at this Institute under AICRP throughout the
country in addition to the fluff supply programme to various state organizations takes care of
the twin objectives of developing varieties with wider and location specific adaptation.
In order to give a fillip to the location specific genetic response and also to hasten
varietal spread, a number of sugar factories with R & D facilities have been co-opted under
the Institute Industry Interface for clonal evaluation of Co canes parallel to the AICRP
programme. This arrangement is expected to go a long way in identification and
popularization of location specific varieties.
SELECTED REFERENCES
Heinz, D.J.,1987. Sugarcane improvement through breeding. Developments in Crop Science
11. , Elsevier, New York
Hogarth , D.M., 1987. Genetics of sugarcane in “ Sugarcane Improvement through Breeding”
Ed, D.J.Heinz, Elsevier, New York.
Mohan Naidu K. et al. 1987. “Sugarcane Varietal Improvement”, Proc. Int. Symp. Platinum
Jubilee, Sugarcane Breeding Institute, 1987.
Stevenson G.C. 1965 . Genetics and Breeding of Sugarcane, Longmans, London
12
Thuljaram Rao J.1987 , Sugarcane origin, taxonomy, breeding and varieties in. “Sugarcane
Varietal Improvement”, Proc. Int . Symp. Platinum Jubilee, Sugarcane Breeding
Institute.
ANNEXURES
Table 1: Current national production scenario
YearArea(MH)
Cane produced (MT)
Productivity (T/Ha.)
Recovery%
Sugar production
(MT)
Actual* 1994-1995 3.87 276 71.3 09.92 14.64
Actual* 2000 4.23 299 70.8 10.20 18.20
Projection** 2010 4.10 348 85.0 10.75 22.48
* Indian Sugar April, 2001 ** Vision 2020, Sugarcane Breeding Institute Perspective Plan
Table 2: Productivity Group
High > 70 T/Ha. Tamilnadu, Maharashtra, Gujarat, Karnataka, Andhra Pradesh
Medium 60-70 T/Ha. Uttar Pradesh, Haryana, Punjab, Orissa, West Bengal, Kerala
Low < 60 T/Ha. Bihar, Madhya Pradesh, Rajasthan, Assam
Table 3: Recovery Group
High > 10.0% Maharashtra, Gujarat, Karnataka
Medium 9-10% Uttar Pradesh, Punjab, Haryana, Madhya Pradesh, Rajasthan, TamilNadu
Low < 9% Bihar, West Bengal, Assam, Kerala, Orissa
(Source: Mangala Rai, T.C.Ramana Rao and C.P.Singh, 1992- Achievement Report of Sugarcane Adaptive Research Programme)
Table 4: Projected requirement (2020)
Total sugar from cane 27.9 million tonnes
Total cane production 415 million tonnes
Productivity per hectare (National) 100 Metric tonnes
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Recovery Percent 11%
Expected population size 1.36 Billion
Per capita requirement 20.14 kg
(Source: Vision 2020, Sugarcane Breeding Institute)
Table 5: Theoretical maximum yield of sugarcane and the records achieved
THEORITICAL YIELD ESTIMATED
Average daily solar radiation 500 cal cm-2 d-1
Solar use efficiency 3.6%
Grams per day/sq.metre 129 grams
Yield of total plant matter in a full year(Fresh weight) 470 mt ha-1 yr –1
Cane yield (fresh weight) 340 mt ha-1 yr –1
REALIZED YIELD
USA- Hawaii(Ham , 1969) 255mt /ha
India-Vapi ( 2000) 340 mt/ha
(Source: Moore, 1987)
Table 6: Area and production of cane in different regions (1999-2000)
Subtropics Tropics
Area 2.501 M. Ha. (59%) 1724 M. Ha. (41%)
Production of cane 141 M T (47%) 158 M T (53%)
Productivity 56 T/Ha 92 T/Ha
(Source: Indian Sugar, April, 2001)
Table 7: Sugarcane area, production and productivity in various countries
(1997-98)
Country Area M Ha. Production MT Productivity T/Ha.
India 3.93 279.5 71.1
Brazil 4.04 249.3 61.6
Cuba 1.35 67.0 49.6
China 1.06 57.1 53.9
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USA 0.32 27.1 84.0
Australia 0.31 25.4 82.0
Indonesia 0.30 25.5 85.0
Fiji 0.09 4.3 43.4
Mauritius 0.07 6.13 81.7
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CONVENTIONAL SUGARCANE SELECTION SCHEME IN INDIA FOR
SELECTION OF SUGARCANE VARIETIES
CROSSING AT COIMBATORE
SEEDLING
SEEDLING EVALUATION
SELECTION 1 YEAR
CLONAL TRIAL I 1 YEAR
CLONAL TRIAL II 1 YEAR
CLONAL TRIAL III 1 YEAR
PRE-ZONAL VARIETAL TRIALS 2 YEARS100 to 120 clones testing for diseases
COIMBATORE JAMKHANDI CHAGALLU MOTIPUR KARNAL(Tamil Nadu) (Karnataka) (Andhra Pradesh) (Bihar) (Haryana)
“Co” VARIETIES
ZONAL VARIETAL TRIALS 4 YEARS
All India Co-ordinated Research Project on Sugarcane
PENINSULAR EAST COAST NORTH WEST NORTH CENTRAL ZONE ZONE ZONE ZONE
VARIETAL RELEASE IN THE RESPECTIVE ZONES
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SUGARCANE VARIETIES SUITABLE FOR PENINSULAR ZONE
K.V.BHAGYALAKSHMI AND T.V.SREENIVASAN
Varieties have played a major role in the expansion and sustenance of sugar
industry in the peninsular zone of the tropical India. This zone which is the largest,
comprise of Gujarat, Maharashtra, Madhya Pradesh, Interior Andhra Pradesh, Tamil
Nadu, Karnataka and Kerala. Major states like Maharashtra, Karnataka, Gujarat and
Tamil Nadu records average yield of 80 t/ha and above. Thus, this is at present the most
productive zone in the whole of the country. This zone is comparable to any other major
sugar producing countries in the world with respect to per hectare sugarcane production.
Climatically the zone is very suitable for high sugarcane productivity. However,
severe constraints such as drought in parts of Maharashtra, Madhya Pradesh, Tamil Nadu
and Northern Karnataka, lack of low temperature during maturity phase in Tamil Nadu,
parts of Karnataka and Kerala, emergence of wilt and red rot in some areas of Tamil
Nadu and Gujarat limits the further improvement in productivity.
Evolution of sugarcane varieties - current status
Sugarcane varieties are evolved through hybridization and selection. Since, most
of the sugarcane varieties flower and set seeds at Coimbatore, all crosses meant for the
whole country is made at Coimbatore every year during September to December. In this
programme besides Sugarcane Breeding Institute, 22 Centers participate through the
AICRP (s). From the raising of seedlings by sowing true seeds, to the identification of
promising new clones at the research centres, it takes about 6 to 7 years depending upon
the selection programmes and methodologies utilized at each Centre. Another 5 years are
required for a variety to come to the release stage through the state varietal trials for state
releases and zonal varietal trials of AICRP (s) for central varietal release for the zones.
Since, the availability of seed of a newly identified variety will be limited at this stage at
the research centres, it takes another 4 to 5 years for the spread of a new variety in
substantial areas. Thus, 17 to 18 years are required for a new variety to reach the farmer.
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Current varietal position
The major varieties grown in various states of the zone at present include:
1. Maharashtra Co 740, Co 8014, Co 7527, CoC 671, Co 8011, CoM
88121, Co 86032, Co 85004, CoM 92121, MS 92122,
Co 91010, Co 92020, Co 89010
2. Madhya Pradesh CoC 671, Co 7704, Co 6806, Co 62175, Co 8014,
Co 8021, CoLk 8001, Co 86032
3. Gujarat CoN 84138, CoN 85135, Co 89012, CoC 671, Co 6304,
Co 7527, Co 8338, CoA 7602, Co 62175, Co 86032
4. Karnataka
South Karnataka Co 62175, Co 7804, Co 8371, Co 86032, CoVc 89249
North Karnataka CoC 671, Co 86032, Co 89014, Co 8359, Co 85002,
Co 88028, Co 85246, Co 92020, Co 8014, Co 8011
5. Andhra Pradesh 83 V 15, 92 V 102, 85 A 261, Co 86249, 81 V 48,
CoR 8001, Co 88025, Co 86249, Co 8011, Co 85061,
Co 7508, Co 7805, CoT 8201, Co 8013
6. Tamil Nadu Co 86032, CoC 671, Co 97009, CoC 90063,
CoG 93076, Co 87044, Co 86010, CoSi 95071,
Co 8021, Co 86249
All of the above varieties currently under cultivation have the potential of high
yield and good quality if the planting and harvesting schedules are closely monitored and
the available improved crop production and protection technologies are usefully utilized.
These technologies include staggered planting and harvesting to keep the age of the crop
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between 12 to 13 months, adequate attention on three tier nursery programme to provide
quality seed, use of organic manures and fertilizers in time, biofertilizers, water
management, cultural practices to overcome problems of drought, efficient ratoon
management, disease and pest surveillance and their control measures.
VARIETAL REQUIREMENTS OF THE ZONE BY 2000 AD AND BEYOND
Emphasis on varietal improvement should be shifted to identify varieties for
adverse conditions especially for drought tolerance, so that the yield levels of low
productivity areas could be improved. In order to sustain the production costs at the
present level, identification of fertilizer use efficient, multi-ratooning varieties, which are
suitable for mechanical harvesting will be required. The varieties mentioned above
should be screened for identifying varieties meeting these requirements.
A careful look at the varietal position in peninsular zone will reveal that there are
many varieties ready for adoption and also many in the pipeline. There are varieties
capable of giving high cane yield and fairly good recovery leading to higher per hectare
sugar production. Similarly there are also varieties with high sugar and moderate cane
yield suitable for fitting into a meaningful planting and harvesting schedule. It should be
possible to maximize the sugar production with these varieties by utilizing the available
crop management practices. In the future also the breeders efforts will continue to be
directed towards evolving varieties which can produce higher sugar yield per hectare
under various stress situations and for ensuring stability in crop production. The industry
should be equipped with technologies to utilize the sugarcane plant as a whole rather than
utilizing the present level of just around 10% of the total biomass.
Instead of few widely adapted varieties like Co 419, Co 740, Co 1148 and CoS
767 which prevailed earlier, we have now a wide spectrum of varieties suited for
different environmental conditions and which can be planted and harvested at different
periods as per the requirements. the varieties that will be in cultivation upto 2005 to 2007
AD are already in the pipeline and so suitable varieties from these must be identified for
improving the sugar output.
The Peninsular zone is the largest with 18 locations. Zonal varietal trials are
conducted for 4 years with each set of entries as Initial varietal trial for one year and
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Advanced varietal trial for two years as two plant and one ratoon crop after one year of
multiplication. Both early and midlate varietal trials are conducted at each location.
Since 1997, progressive sugar factories having a research and development wing will be
also involved in the farm trials of elite clones selected for the advanced varietal trials of
the zones, to augment information on technological aspects as well as on varietal
performance at the time of release. It will also ensure quicker spread of the new variety
when it is finally released. The performance of varieties given in Table 1 and 2 will
reveal the position as far as varietal front is concerned.
REFERENCES
Ethirajan A.S., 1987. Sugarcane hybridisation techniques. Copersucar International Sugarcane Workshop, Brazil. pp : 129-148.
Mariotti, J.A. 1987. Selection for stability and adaptability. Copersucar International Sugarcane Workshop, Brazil. pp : 249-267.
Sreenivasan, T.V. and K.V.Bhagyalakshmi, 1993. Varietal improvement for increasing sugar production. Indian J. of Sugarcane Technol. 8 (2): 85-100.
Sreenivasan, T.V. and K.V. Bhagyalakshmi, 1995. Genetic improvement of sugarcane. National Symp. on "Strategies to enhance sugar productivity" at IISR, Lucknow.
20
Table 1: General information on recently released varieties with AICRP(s)
Varieties Parameters States
1. Co 8371 (identified in 1997)
Very high yield; moderate sugar; midlate
Karnataka, Maharashtra
2. Co 85004 (1989) Early; high sugar; moderate yield Maharashtra, Gujarat
3. Co 85019 (1995) High yield, high sugar early to midlate; moderately resistant to red rot, tolerant to drought, fast growing
Tamilnadu, Pondicherry
4. Co 86010 (1996) High yield, high sugar; MR to red rot, fast growing, tendency for lodging
Tamilnadu, Pondicherry
5. Co 86032 (1994) High yield; high sugar; moderately susceptible to red rot; tolerates drought; midlate
Tamilnadu, Karnataka, Maharashtra, Gujarat
6. Co 86249 (1997) Yield on par with present day cultivars; resistant to red rot; early to midlate
Coastal Tamilnadu and Andhra Pradesh
7. Co 87025 (1994) Erect, high yielding, midlate, nonflowering; suitable for mechanical harvest
Peninsular zone
8. Co 87044 (1994) High yielding, high sugar yield, midlate Peninsular zone
9. Co 88017 (1997) Released as ‘Madhumathi’ by Thiruvalla, Kerala. High yielding, good quality, tolerates waterlogging
Kerala
10. CoM 88121 (1995)
Released as “Krishna” for Maharashtra; high cane and sugar yields; nonflowering; midlate; high tillering
Maharashtra and North Karnataka
11. Co 91010 (1999)
High cane and sugar yielding, midlate; high tillering
Peninsular zone
12. Co 8014 (1994) Released as ‘Mahalakshmi’ for Maharashtra. Early to midlate; shy flowering, good cane and sugar yields
Maharashtra and North Karnataka
21
Table 2: Data on cane yield, sucrose percent and CCS t/ha of recently released varieties (Data from AICRP(s) trials)
Co 85004 (Co 6304 x Co 740)
Cane yield t/ha
Coimbatore Melalathur Pravaranagar Akola
Co 85004 103.63 109.43 101.2 89.75CoC 671 98.46 90.13 84.3 81.25Co 7219 88.0 - - 98.60
Sucrose percentCo 85004 18.07 19.23 15.93 19.15CoC 671 18.66 19.73 16.0 19.35Co 7219 18.83 - 15.76 18.15
Sugar yield t/haCo 85004 13.0 15.53 11.03 12.0CoC 671 12.93 12.80 9.13 10.85Co 7219 11.23 - - 12.65
Co 86032 (Co 62198 x CoC 671)
Cane yield t/haCoimbatore Pravaranagar Kolhapur
Co 86032 119.9 125.3 107.1Co 7219 80.0 112.4 87.2Co 6304 86.7 91.1 -
Sucrose percentCo 86032 21.1 19.2 20.2Co 7219 20.9 18.7 19.5Co 6304 19.5 18.0 -
Sugar yield t/haCo 86032 17.6 17.1 15.5Co 7219 11.6 14.5 13.3Co 6304 11.5 12.4 -
22
Co 86249 (CoJ 64 x CoA 7601)
Cane yield t/haChiplima Cuddalore Kovvuru
Co 86249 107.3 118.6 84.1Co 6304 98.2 113.9 63.0Co 7219 98.6 107.0 66.3
Sucrose percentCo 86249 18.6 18.5 17.8Co 6304 18.7 16.6 20.3Co 7219 18.9 17.5 18.4
Sugar yield t/haCo 86249 10.5 15.6 10.3Co 6304 9.9 13.3 8.8Co 7219 9.4 13.2 8.3
Co 87025 (Co 7704 x Co 62198)
Cane yield t/haCoimbatore Navsari Pune
Co 87025 97.6 90.9 102.9Co 6304 82.5 65.4 57.9Co 7219 71.8 -- 80.5
Sucrose percentCo 87025 18.9 18.0 16.8Co 6304 17.0 16.8 16.1Co 7219 18.3 17.1 16.2
Sugar yield t/haCo 87025 13.1 12.0 11.6Co 6304 9.8 7.9 6.4Co 7219 9.3 8.9 8.9
23
Co 87044 (Co 62198 x CoC 671)
Cane yield t/haCoimbatore Sankeshwar Navasari Pravaranagar
Co 87044 91.8 116.6 115.4 126.9Co 6304 82.5 -- 65.4 102.5Co 7219 71.8 97.7 -- 117.6
Sucrose percentCo 87044 18.8 18.6 17.5 18.2Co 6304 17.0 -- 16.8 17.7Co 7219 18.3 19.0 -- 19.3
Sugar yield t/haCo 87044 12.2 15.1 14.4 16.1Co 6304 9.9 12.8 7.9 12.7Co 7219 9.3 12.8 -- 16.2
Co 8371 (Co 740 x Co 6806)
Cane yield t/haCoimbatore Mandya Pune
Co 8371 112.0 169.8 125.8Co 6304 97.8 161.4* 112.2Co 7219 96.5 -- 120.0
Sucrose percentCo 8371 18.8 20.2 17.6Co 6304 19.5 18.2* 17.5Co 7219 20.2 -- 19.2
Sugar yield t/haCo 8371 14.4 24.4 15.3Co 6304 13.6 20.5* 14.0Co 7219 13.7 -- 15.8
* Co 62175
24
Co 91010 (Co 312 x Co 775)
Cane yield t/haCoimbatore Padegaon Kolhapur Pravaranagar
Co 91010 126.92 106.83 114.54 122.81Co 6304 105.92 70.42 95.45 79.13Co 7219 101.56 96.16 91.08 88.02
Sucrose percentCo 91010 20.87 20.12 17.76 19.50Co 6304 19.06 20.36 19.81 19.27Co 7219 20.94 20.30 19.70 19.43
Sugar yield t/haCo 91010 18.47 15.20 14.38 16.92Co 6304 14.06 11.23 13.10 12.00Co 7219 14.93 13.20 12.62 15.70
Co 85019 (Co 7201 x Co 775) Midlate / Early
Co 85019 Co 6304
Cane yield t/ha 117.0 105.0Sucrose % 20.0 18.3CCS t/ha 16.3 13.3
Co 86010 (Co 740 x Co 7409) Early / Midlate
Co 86010 Co 6304
Cane yield t/ha 130.8 120.9
CCS % 10.9 11.9
25
CCS t/ha 14.2 14.2
CoM 88121 (Co 740 x Co 6806) Midlate
CoM 88121 Co 6304 Co 7219
Cane yield t/ha 96.3 86.0 87.0
Sucrose % 19.1 18.1 18.6
CCS t/ha 13.0 10.8 11.6
Co 91010 (Co 312 x Co 775) Midlate
Co 91010 Co 6304 Co 7219
Cane yield t/ha 116.0 83.2 93.5
Sucrose % 19.1 18.8 20.3
CCS t/ha 14.3 11.1 13.6
Co 8014 (Co 740 x Co 6304) (From Sankeshwar)
Co 8014 Co 7219
Cane yield t/ha 136.7 126.0
Sucrose % 18.8 19.9
CCS t/ha 19.3 18.1
26
BREEDING METHODOLOGIES AND SEED NURSERY PROGRAMME
R.NAGARAJAN
Sugarcane Breeding Institute was established at Coimbatore in 1912 with the
major aim of evolving improved varieties for different regions of India. The fact that
sugarcane flowers profusely and set seed abundantly led to the establishment of
Sugarcane Breeding Institute at Coimbatore. Because flowering and good seed set are
prerequisite for any breeding programme.
Though sugarcane flowers at Coimbatore, flowering occurs only during October
to December and hence hybridization programme can be taken up only during this period.
Most of the clones flower though a few do not flower. But all the varieties will not
flower at a time. Certain clones flower during the third week of October and some will
flower in December first week and so hybridizing such clones will be difficult. Hence,
synchronization of flowering is also very important. Besides this a parent must give good
seed set so that it can be exploited in breeding. Hence, hybridization programme should
take into consideration the flowering synchronization of parents chosen.
Parental choice depends on many factors besides flowering and synchronization.
Performance of sugarcane clones for cane yield, sugar content, resistance to pest and
disease characters is considered while selecting parents. Their performance in crosses is
also considered important. Because all crosses may not have equal value, since certain
crosses throw better progenies at a higher frequencies which is desirable. Hence,
possession of desirable attributes and capacity to transmit them to their progenies are
very important in choice of parents.
Hybridization
Hybridization requires proper identification of male and female based on pollen
fertility. Generally those clones possessing less than 30% pollen fertility are used as safe
female parents. Those with above 60% pollen fertility are used as good male parents.
Those falling in the range of 30% to 60% are used as male or female depending upon the
fertility of the other parent. Those with higher pollen fertility will be taken as male
parent.
27
A female flower of female arrow in sugarcane has to be made ready for
hybridization when the tip of inflorescence start emerging from short blade and it has to
be caged in order to prevent undesirable pollen falling on its stigmatic surface. Hence, as
and when the arrow start emerging out in those clones which are marked as female
parents, an aluminum cage is suspended from a bamboo lantern erected by the side of the
cane to be used as female. The cage is covered by a cloth bag and is brought over female
flower to enclose it.
The flower starts opening from top and proceed downwards. It takes 7-8 days for
the whole flower to emerge out completely from short blade and so pollen dusting on a
flower also take 7 – 8 days for completion of a cross. When a particular cross is decided
then the female flower is enclosed in a cage as said above. Every day morning, pollen
from designated male parent has to be collected and dusted on the female flower. Before
anthesis take place in field, that portion of the male flower which is supposed to open on
that day is clipped around 5 a.m. and brought to laboratory and kept on a butter paper or
newspaper and kept under artificial light to make it open and dehisce pollen on the paper
which happens around 6.45 to 7 a.m. Afterwards the clipped portion of flower with
dehisced pollen in the paper is rolled and taken to field. The cage on the female flower is
lifted slightly up and the pollen from male parent is dusted on that portion of female
flower, which has opened on that day. The cage is brought down and female flower is
enclosed again. This process is continued for 7 – 8 days till the bottom of female flower
has opened. Afterwards the caged female flower is left for seed set and maturity. The
maturity of seed takes about a month after crossing. The matured seed or fuzz on the
arrow are collected, cleaned and dried and kept in paper bag. As there is no dormancy
the seed can be sown immediately. If any delay in sowing is anticipated, it is better to
store them under low temperature to preserve viability.
Fluff sowing
The fluff or fuzz (true seed) collected and processed are sown in trays filled with
sand, silt and horse dung manure mixed at a ratio of 1 : 1 : 1. 2-3 gms of fluff is sown in
each plastic tray and covered with a thin layer of sand, soil and horse dung mixture and
watered. Normally fluff sowing is taken up during the month of January. The trays are
kept inside a mist chamber with facility for controlling temperature and humidity. A
28
temperature of 33°C and RH of 55% is favourable for good germination. Germination of
fluff can be noticed on fourth day and germination will be complete by a week's time.
Selection in seedling and clonal stages
When the seedlings attain an age of 40 days, they will be transplanted individually
in small polybags to facilitate faster and better growth. The same soil mixture used for
fluff sowing is used in seedling transplanting in polybags. After about 30-40 days the
seedlings from polybags are taken and planted in field. The seedlings are spaced 60 cm
between them and space between ridges is kept at 90 cm. Seedlings are planted in field
normally during March-April, so that they can be screened during next February – March
at the age of 11-12 months in field. As the variation due to environment is very high at
this stage, selection can be done for more dependable characters like H.R. brix and stalk
diameter. Hence, data on the above said attributes are recorded and about 25-30% of
superior seedlings are selected for evaluation in first clonal trial.
The clones selected from seedlings are evaluated for cane yield and quality
characters in first clonal trial in smaller plot size that are non replicated. The types
selected from this trial are further screened in second clonal trial and then in prefinal
clonal trial for cane yield and quality characters, viz. juice brix, sucrose and purity. The
selections from prefinal clonal trial will be forwarded to pre-zonal trial for multilocation
evaluation in the Research Centres of Sugarcane Breeding Institute located at Jamkhandi
(Karnataka), Chagallu (Andhra Pradesh), Motipur (Bihar) and Karnal (Haryana) besides
Coimbatore. Evaluation of PZVT is done for cane yield, juice brix, sucrose, purity, CCS
%, CCS/plot, resistance to important diseases like red rot and smut. Based on the above
characters, those clones which are superior to check varieties atleast for one of the
economic characters are selected, designated as Co canes and proposed for testing in
Zonal Varietal Trial under AICRP in the appropriate zones; viz., Peninsular, East,
Coastal, Northwest, North Central and North East. In Zonal Trial, varieties are used for
two plant and one ratoon and screening is done for all cane yield and juice quality
characters. Best ones are selected and recommended for release as varieties.
Seed production
The breeder seed production of approved 'Co' varieties is taken up at SBI and
quality seed is provided to user agencies. Good setts of selected varieties are heat treated
29
and planted for breeder seed production. The seed plots are monitored periodically and
kept free of varietal mixtures, pests and diseases. Good seed material is harvested and
provided to different organizations at the age of 6 – 8 months.
BREEDING FOR RED ROT RESISTANCE
U. S. NATARAJAN
INTRODUCTION
Red rot caused by Colletotrichum falcatum Went. is the most serious disease of
sugarcane in India. It is also the oldest mentioned disease of sugarcane dating back to the
times of Buddha. Barber in 1901 made the first recorded report of red rot occurrence in
India. Since then a number of red rot epidemics have been reported, especially in eastern
Uttar Pradesh, northern Bihar and pockets of Punjab. These epidemics have resulted in
the devastation of local varieties and elimination of many early Coimbatore bred varieties
including Co 312 and Co 453. In recent times, CoJ 64, which had been the most popular
variety because of its highest recovery, was one among the several varieties that
succumbed to red rot in the recent past. The disease essentially confined to northern India
and parts of north-western India and Andhra Pradesh for several decades has started
spreading to other parts of southern India as well, especially in the east coast zone, taking
a heavy toll of many improved varieties, the most notable one being CoC 671. As a
consequence breeding for red rot resistance has emerged as an important facet of varietal
evolution.
GENETIC MECHANISM OF RESISTANCE
Diseases can be broadly categorized into two different groups:
30
1. Diseases exhibiting race specific resistance
2. Diseases that do not show race specific resistance
For instance in sugarcane itself red rot belongs to the first category while smut
appears to be in the second category. In the first category of diseases there are two
components of resistance namely, race specific resistance / vertical resistance and race
non-specific resistance / horizontal resistance / field resistance / partial resistance. In the
second category of diseases only race non-specific resistance appears to be operating.
Race specific resistance has its origin in Flor's 'gene-for-gene hypothesis' wherein he
stated, through extensive work on flax rust, that 'for every gene for resistance in the host
there is a corresponding gene for virulence in the pathogen'.
Biometrically speaking, analysis of variance of disease scores in a two-way table
of a set of host varieties and a set of pathogenic isolates reveals the presence and the
relative magnitudes of the two components of resistance. In such an analysis, the main
effects are due to race non-specificity while interaction effects are due to race specificity
(Table 1).
BIOCHEMICAL / PHYSIOLOGICAL BASIS OF RESISTANCE
Recent research on biochemical aspects of resistance to corroborate Flor's gene-
for- gene hypothesis indicates that the pathogen produces an elicitor (protein) molecule
when it comes into contact with the host and the host in response, produces a receptor
molecule. These two molecules if compatible, polymerize to form a macromolecule that
initiates a cascade of biochemical reactions favourable for the pathogen to feed and
reproduce on the host resulting in susceptibility. If the elicitor and the receptor molecules
are not compatible and hence do not polymerize, presence of this unbound elicitor (a
foreign body as far as the host is concerned), activates the defence mechanism resulting
in the death of the pathogen. This is race specific resistance. In the case of race non-
specific resistance, the biochemical mechanism is not understood in detail. However it
appears that a number of genes governing growth, survival and various metabolic
functions of the host give indirect resistance. This kind of a resistance though not
complete cannot be overcome by the pathogen.
31
BOOM AND BUST CYCLE
'Boom and Bust Cycle' is a serious consequence of breeding for race specific
resistance. When a variety with race specific resistance is released, the disease is
completely under control and the productivity of the crop increases rapidly creating a
boom. However, in a few years time the pathogen is able to adapt itself to the newly
released variety and starts attacking it resulting in susceptibility. This results in a bust in
productivity. The breeders and pathologists work hard and replace this variety with a new
resistant one. This variety also succumbs to the disease in a few years and the story is
repeated. This phenomenon is called Suneson's 'Boom and Bust Cycle' and is a
consequence of race specific resistance. In Bihar, where red rot occurs in a serious
proportion, this kind of a phenomenon is observed.
GENETIC SOURCE OF RESISTANCE
The present day sugarcane cultivars have emanated as complex hybrids involving
four different species: S. officinarum, S. spontaneum, S. barberi and S. sinense. The latter
two species are considered to have arisen as products of introgression between S.
officinarum and S. spontaneum , thus leaving the present day sugarcane cultivars to be
essentially made up of the cultivated S. officinarum and the wild S. spontaneum. S.
officinarum is essentially susceptible to red rot and gene sources for resistance comes
from S. spontaneum. Thus, it is essential to examine this species as donor for resistance
in terms of both VR and HR.
A natural phytosystem builds up horizontal resistance and the scope for evolution
of vertical resistance is very much limited since it leads to the death of both the host and
the pathogen. S. spontaneum being a natural phytosystem with a contiguous distribution
in the red rot endemic areas together with its ability to propagate naturally by both seed
and vegetative means, forms an ideal candidate for evolution and maintenance of
horizontal resistance. However, during the course of breeding sugarcane varieties for red
rot resistance employing specific isolates of the pathogen, there is the possibility of the
breeder and pathologist unwittingly shifting the host-pathogen system from one of HR-
friendly to VR-friendly. This has been very well established in other crops and there are
enough indications in sugarcane as well against red rot. When 99 clones belonging to
32
different groups were tested against four different isolates of red rot (Table 2), there was
a progressive decrease in the HR/VR ratio as the number of S. spontaneum chromosomes
decreased (Fig. 1).
GENETIC DIVERSITY
It is an acknowledged fact that the present day varieties world over constitute a
narrow genetic base viewed in the context of the wide spectrum germplasm materials
available. The following are the clones of S. officinarum and S. spontaneum which
constitute this narrow genetic base of present day cultivars:
S. officinarum: Ashy Mauritius, Badila, Banjermasin Hitam, Black Cheribon,
Fuji, Green Sport, Kaluthai Boothan, Lahaina, Loethers, Striped
Mauritius, Vellai
S. spontaneum : CBE form, Java form
Hence it is very important to involve as many S. officinarum and S. spontaneum
clones as possible for developing improved varieties. Work has been in progress in this
direction at this Institute during the past 15-16 years involving the following clones.
1. S. officinarum :28 NG 51, 28 NG 93, 28 NG 210, 28 NG 221, 28 NG 224, 57 NG
78, 57 NG 110, NG 77-63, NG 77-92, NG 77-99, NG 77-137 &
Uahi-e-pele.
2. S. spontaneum :SES 44A, SES 69, SES 87A, SES 90, SES 93, SES 131, SES 198,
SES 275, SES 515-7 & SES 538.
3. Cultivars :
Resistant : Co 7201,Co 7314, Co 7704, Co 8353, Co 8365, Co 86010,
Co 86011, Co 86249, Co 87045, Co 88013, Co 89009,
Co 93009, Co 94008, CoA 7602
Susceptible : Co 6806, Co 775, Co 1148, Co 62198, Co 6304, Co 8338,
Co 8347, Co 8371, Co 85002, Co 85007, CoC 671, CoC 85061,
Co 88037, Co 92002
33
This has given a rich dividend and a number of promising clones combining
productivity and red rot resistance has been developed and is being evaluated at red rot
prone areas.
SCREENING TECHNIQUES
Screening can be done either under artificial inoculation conditions or under
natural conditions. There are three different artificial inoculation techniques that are
being followed in our country. These are:
1. Controlled condition testing
2. Plug method of inoculation
3. Nodal method of inoculation
To compare these techniques a diverse set of 99 clones were inoculated with four
different isolates and the disease resistance was scored on a scale of 1 to 5.
It was generally observed that compared to CCT method, plug and nodal methods
gave more number of resistant types indicating that CCT method is too drastic to identify
potentially resistant types. Regression graph (Fig.2) shows a close relationship between
plug and nodal methods with over 80 % of the variation being accounted for by linearity
and a near unit regression coefficient of 0.9. On the contrary, the relationship between
CCT and plug/nodal method was not substantially high, since only 30-35 % of the
variation being accounted for with a low regression coefficient.
Under artificial inoculation conditions, the resistance sought to be achieved is
generally race specific. This carries the risk of 'resistance break down' in the event of
appropriate change in the pathogenic population as discussed already. In order to obtain
resistance that could be stable (race non-specific), it is essential to score disease reaction
for several years, especially in ratoon crops in endemic areas before the eventual release
of a variety. This is a cumbersome and long drawn process, nevertheless a practically
useful one. Alternately, clones selected for agronomic worthiness could be screened for
red rot resistance under natural conditions providing inoculum through infector rows. The
crop could be ratooned to ensure disease spread and resistant clones identified thereafter.
This Institute has initiated such an exercise at Sugarcane Research Station, Cuddalore, in
34
collaboration with TNAU scientists. At present more than 100 clones are under
evaluation with inoculum being provided by CoC 671 isolate.
INHERITANCE OF RESISTANCE
When we consider the original species that have given the present day varieties, S.
officinarum is generally susceptible while S. spontaneum is resistant. In the case of S.
barberi / sinense considered to be hybrid derivatives, there are both resistant and
susceptible types.
Information on inheritance of red rot resistance in the present day varieties as well
as in the advanced interspecific genetic stocks is essential to formulate appropriate
breeding strategies. In such an attempt, around 1200 clonal progenies from 29 different
crosses of diverse genetic origin were evaluated for red rot resistance. The mode of
inheritance was investigated both for race-specific and race non-specific components.
To find out inheritance of race specific resistance, c2 test for goodness of fit was
worked out for simple mendelian segregation (Table 3). It was found that out of 7 crosses
under R x R category, four crosses showed goodness of fit for 3:1 segregation while there
were significant deviations in the other three crosses. Out of 8 crosses under R x S
category, 1:1 segregation was observed in six crosses, the other two showing significant
deviations. In the S x S category, 5 crosses were studied. Although all progenies are
expected to be susceptible according to mendelian segregation, frequent occurrence of
resistant progenies were observed. This gave a clear indication that race specific
resistance alone could not wholly explain the pattern of inheritance. Hence parent-
progeny regression was worked out to find out the level of additive gene action (race
non-specific) that confers red rot resistance. It was found that nearly 50% of the variation
could be attributed to this component of resistance (Fig.3).
The following inferences could be drawn from the above:
1. Red rot resistance is composed of two components, namely, race specific and race
non-specific, almost of equal strength.
2. Race specific resistance is governed by a single dominant gene.
3. Since the level of race non-specific resistance is nearly 50%, there is very good scope
for evolving resistant varieties that would not 'breakdown'.
35
STABLE RESISTANCE
There are many instances of stable resistance in crop plants. In sugarcane, the red
rot resistance shown by Co 1148 is an outstanding example of stable resistance. Released
for cultivation in mid 50's, it has stood the test of time for over three decades and still
enjoys a significant presence in terms of acreage in red rot endemic areas of subtropical
India. However a summary of reactions of this variety to various isolates of red rot
following plug method of inoculation over a six-year period (Table 4) is not likely to
characterize this variety as resistant. Based on lesion length the variety would have been
rated as susceptible one on many occasions. Similarly in Tamil Nadu, a major sugar cane
belt in tropical India, CoC 90063 appears to be such an example. The registered area
under this variety has progressively increased from around 16000 acres in 1993 to around
82000 acres in 1997 in Tamil Nadu where red rot occurs in a very severe proportion in
the coastal and river belts. The variety has come to occupy the number one position from
1996 onwards in this southern state of India. Similar to Co 1148, this variety is also
reported to be susceptible under artificial disease testing conditions against the specific
isolate. Under field conditions however, CoC 90063 is essentially resistant. A close
scrutiny of the data in terms of the area occupied by this variety vis-à-vis the three highly
susceptible varieties CoC 671, CoC 85061 and CoC 92061 in coastal Tamil Nadu where
red rot had a devastating effect during 1993-1997 supports this fact. While the area
drastically declined for these three susceptible varieties, the area occupied by CoC 90063
increased tremendously during the corresponding period (Fig.4).
Under artificial inoculation techniques it is difficult to identify a clone which
would eventually turn out to be a variety with stable resistance. Nevertheless, the
problem can be tackled at the field level. Since 6 - 7 years of clonal evaluation precedes
varietal release, there should be no difficulty in assessing the red rot resistance under
field conditions, especially in ratoon crops, for several years before the eventual release
of the variety. This would adequately ensure identification of varieties with stable
resistance. Another method is to look for resistant progenies from crosses involving
susceptible parents so as to avoid the ‘noise’ that would be created by genes of
dominance effects when resistance parents are used for crossing. Such transgressive
segregants are the products of additive genetic action and they are bound to show stable
36
resistance. In fact there are a number of such varieties that are already available, some of
which are listed below. CoC 90063 mentioned above itself is an example.
Resistant Variety Susceptible parents
Co 7704 Co 740 x Co 6806
Co 8021 Co 740 x Co 6806
Co 86010 Co 740 x Co 7409
Co 93009 Co 678 x Co 775
CoSi 95071 CoC 671 x MS 68/47
CoC 90063 Co 6304 x CoC 671
As a long term measure however, introduction of new variants of S. spontaneum
in breeding programmes in order to increase the probability of obtaining varieties with
stable resistance is being undertaken expeditiously.
CONCLUSION
Breeding for red rot resistance has become one of the important activities in
sugarcane improvement owing to the seriousness of the disease. There are two
components of red rot resistance, namely, race specific and race non-specific. While race
specific resistance is easy to breed and gives complete resistance, it is notoriously fickle
and leads to 'Boom and Bust Cycle'. Race non-specific resistance, on the other hand, is
difficult to breed and gives partial resistance, but is stable. S. spontaneum is the primary
source of red rot resistance and hence introducing wide diversity of this species in
nobilization programmes would sustain varietal development work for a very long time.
While race specific resistance is inherited as a simple dominant mendelian trait, race non-
specific resistance is governed by additive gene action. There are substantial levels of
race non-specific resistance against red rot and hence varieties with stable resistance
could be developed
Table 1. Vertical and Horizontal resistance
Vertical resistance
Host Pathogen P1 P2 P3 P4
V1 S R R R
37
V2 R S R RV3 R R S RV4 R R R S
Analysis of variance
HostPathogen
T
P1 P2 P3 P4 Source df SS MS
V1 9 0 0 0 9 Total 15 243V2 0 9 0 0 9 Varieties 3 0 0V3 0 0 9 0 9 Isolates 3 0 0V4 0 0 0 9 9 V X I 9 243 27T 9 9 9 9 36
Horizontal resistance analysis of variance
HostPathogen
T
P1 P2 P3 P4 Source df SS MS
V1 9 8 7 6 30 Total 15 100V2 7 6 5 4 22 Varieties 3 80 27V3 5 4 3 2 14 Isolates 3 20 7V4 3 2 1 0 6 V X I 9 0 0T 24 20 16 12 72
Table 2. HR / VR Variance ratio in different groups of clones
Numberof
clones
ApproximateS. spontaneumchromosomes
Group s2 HR s2
VR s2 HR : s2
VR
N1 4 1.3125 0.2292 5.7 : 1 32CN1 4 0.9306 0.8403 1.1 : 1 22CN21 7 0.1555 0.3652 1 : 2.3 18CCN1 15 0.2678 0.6604 1 : 2.5 16N2 21 0.2516 0.8782 1 : 3.5 16CN2 23 0.1381 0.5200 1 : 3.8 14Intervarietal 19 0.0746 0.5647 1 : 7.6 10N3 6 0.0776 1.3308 1 : 17.1 8Over all 99 0.0854 0.6769 1 : 7.9
Table 3. Mendelian segregation for red rot resistance
38
S.No. Cross R S Tot c2
Resistant x Resistant (Red rot x Rr 3:11. 93806 x Co 88013 86 23 119 0.782. Co 7201 x CoA 7602 31 14 45 1.083. Co 7201 x Co 86011 71 34 105 3.044. Co 7201 x N21 0714 24 12 36 1.335. Co 7201 x N22 3506 19 14 33 5.946. Co 7201 x N2 S1 0101 22 12 34 2.627. Co 7201 x N2 S1 0109 46 54 100 44.85
Resistant x Susceptible (Rr x rr) 1:18. CoA 7602 x Co 1148 18 7 25 4.849. 931236 x CoA 7602 30 14 44 1.09
10. Co 8371 x Co 86249 21 20 41 0.0211. CoA 7602 x Co 775 22 24 46 0.0912. Co 7201 x Co 775 27 32 59 0.4213. Co 7201 x N11 0624 21 25 46 0.3514. CN2241093 x Co 88013 12 20 32 2.0015. Co 86010 x CN22 37272 14 34 48 8.33
Susceptible x Susceptible (rr x rr) all susceptible 16. 931236 x Co 775 8 20 28 -17. CN22 41093 x Co 775 8 23 31 -18. BGC2 5021 x Co 775 9 36 45 -19. Co 8371 x CN22 37272 11 52 63 -20. Co 62198 x 931112 2 20 22 -
Table 4: Frequency distribution of red rot reaction of Co 1148 against several isolates at U.P. Centres during 1959 – 1964.
Red rot lesion length (class
interval in cm)Frequency Disease reaction class
< 12.5 1 Resistant
12.6 - 25.0 5 Resistant
25.1 - 37.5 13 Moderately Resistant
37.6 - 50.0 12 Moderately Susceptible
50.1 - 62.5 3 Susceptible
62.6 - 75.0 0 Highly Susceptible
> 75.0 1 Highly Susceptible
39
Fig. 1. Effect of Saccharum spontaneum chromosomes onhorizontal and vertical resistance
40
y = 0.14e0.0882x
R2 = 0.99
0
0.5
1
1.5
2
2.5
3
4 12 20 28 36
S. spontaneum CHROMOSOMES
PR
OR
TIO
N O
F H
R/V
R
Fig.2: Relationship between artificial inoculation techniques
Regression of Nodal on Plug Method
y = 0.8783x + 0.7726
R2 = 0.80640
1
2
3
4
5
6
0 1 2 3 4 5 6
Plug Method
No
dal
Met
ho
d
Regression of CCT on Plug Method
y = 0.5042x + 0.5456
R2 = 0.3652
0
1
2
3
4
5
6
0 1 2 3 4 5 6
Plug Method
CC
T M
eth
od
41
Regression of CCT on Nodal Method
y = 0.4441x + 0.6164R2 = 0.2710
0
1
2
3
4
5
6
0 1 2 3 4 5 6
Nodal Method
CC
T M
eth
od
42
Fig. 3: Parent-progeny regression for red rot resistance
Fig.4: Area occupied by CoC 90063 against susceptible varietiesin coastal Tamilnadu
43
y = 0.39x + 2.18R2 = 0.45
2.0
2.5
3.0
3.5
4.0
4.5
5.0
0.0 1.0 2.0 3.0 4.0 5.0
MIDPARENTAL VALUE
PR
OG
EN
Y M
EA
N
0
20000
40000
60000
80000
100000
120000
1993 1994 1995 1996 1997Years
Are
a i
n a
cre
s CoC 671
CoC 85061
CoC 92061
CoC 90063
QUALITY SEED PRODUCTION IN SUGARCANE
R.NAGARAJAN
Seed in sugarcane has two different connotations based on the purpose for which
it is used. True seed or fluff or fuzz taken from sugarcane flowers is one which forms the
basic material for breeders to develop improved varieties. The other one meant to raise
crop in farmer's field is called "setts" which are vegetative propagules or parts of
sugarcane having one, two or more buds having the potential to germinate and produce
plants identical to the variety from which setts are drawn. While the former is useful
only for breeding purpose, the latter is of primary importance from cane and sugar
production point of view.
Every year 10-12% of cane grown is utilized for seed purpose. The quality and
quantity of seed used determine the crop performance. A good quality seed should
ensure maximum germination. The quality of seed depends on age of crop, growing
conditions, varietal purity, incidence of pests and diseases etc. Sometimes, cane of any
age is used to get setts and whole cane is used for seed purpose. In a mature cane, top
half of the cane can be used as seed leaving the bottom half, because germination in
bottom half will be poor in general. The buds at lower portion are old, covered with thick
scales and hence slow to germinate. The lower internodes are more mature and so
contain more sucrose and less reducing sugars and moisture. In the top portion of cane,
buds are young, succulent and without any covering of scales. They also have higher
reducing sugar and moisture content which are favourable for faster and better
germination. Hence, it is better to cut the cane top, which can be used for such purpose,
and use the other portion for crushing which will benefit factory in bettering recovery.
The best option is to grow a crop exclusively for seed purpose. An young crop of
7-8 months old would be ideal for seed purpose which is called a seed nursery. In an
young crop the whole cane has all the favourable factors for maximum germination. The
cane at the age of 7-8 months contains less sucrose, more reducing sugars, moisture
44
content and has young buds. Hence the best option would be to go for quality seed from
the seed nursery crop.
Once newer varieties are released, it is essential to maintain seed nurseries to
produce and provide quality seed to individual grower. The bulkiness of cane seed
pieces, the limited ratio of seed area to plant crop area and most importantly the short life
of cane seed pieces dictate that the seed source be physically near crop area. The
necessity to produce seed on local level underscores the need to understand the
fundamental principles involved in quality seed production.
1. Seed cane should be grown in areas especially designated for seed cane
production i.e., seed nurseries. The concept of seed nurseries permit quality
control in planning and monitoring seed production.
2. Planting procedure followed should ensure freedom from varietal mixtures and
seed borne diseases in nursery areas. Appropriate fallow periods to control
volunteer mixtures and carefully monitored seed treatments to control diseases
prove to be cost effective in the long run.
3. Agronomic practices that will assure ample production of disease free seed
material should be followed.
4. Seed nurseries should be regularly inspected for seed purity (varietal mix) and
freedom from diseases.
5. Seed treatment procedures should be followed at seed cane harvest and should be
aimed at minimizing disease losses and maximizing germination in commercial
fields.
6. Movement of seed between sugarcane growing areas should be regulated.
45
It is necessary to provide good quality seed to farmers in order to maintain yield
levels of varieties. Hence, the role of sugar mills in this activity does not need any
emphasis. A well planned three tier seed nursery programme is a must for every sugar
factory. Some of the important points to be taken care off in the seed nursery programme
are as follows:
1. Land meant for seed production should not have been utilized to grow sugarcane
in the previous year. It is better to avoid sugarcane as immediate preceding crop.
2. Seed plot should be kept free of weeds.
3. Setts used for raising primary nursery must be given heat treatment.
4. It is better to give sufficient row spacing to allow inspection and roguing of
mixtures, disease and pest affected plants, if any.
5. It is necessary to follow good crop management practices to have a healthy
vigorous crop.
6. Regular and periodical inspection of seed nursery by expert personnel is
necessary to keep the crop free from mixtures, diseases and pests.
7. Seed crop must be harvested at the age of 7-8 months.
46
MICROPROPAGATION OF SUGARCANE VARIETIES FOR
QUALITY SEED PRODUCTION
N.C.JALAJA
As a result of the emphasis laid on identifying location specific varieties for
achieving yield and quality improvements in sugarcane, overcoming various constraints
prevalent in different agroclimatic zones of the country, a number of new varieties are
emerging at a much faster rate than ever before. Micropropagation is the only
methodology which can ensure a faster rate of multiplication to ensure seed availability
of these new varieties. When integrated with seed production programme, this will
ensure the availability of quality seeds of the desired variety to the farmers to ensure a
better crop free from diseases and pests. In India, sugarcane micropropagation work was
initiated almost simultaneously at National Chemical Laboratory, Pune and at Sugarcane
Breeding Institute, Coimbatore; While NCL, Pune confined their work with a single
variety Co 740 for the elimination of sugarcane mosaic virus and the multiplication of
virus free material, Sugarcane Breeding Institute standardised the methodology for a
wider spectrum of varieties and popularised the system for quality seed production.
Under the Sugarcane Adaptive Research Project, a micropropagation laboratory was
established at Sugarcane Breeding Institute for producing plants through this technique.
The plants thus produced were distributed to sugar factories located in different parts of
the country in order to demonstrate the usefulness of the technology for quality seed
production. This laboratory also developed a training facility for scientists and
technicians to impart training in all aspects of sugarcane micropropagation. This dual
activity - developing a suitable technology and providing training to develop human
resources to ensure transfer of technology had a good effect. Many sugarcane tissue
culture multiplication laboratories emerged, a few as part of sugar factory R&D and
others as private commercial enterprises.
Farmers are now aware of the usefulness of the system. However, with the
emergence of commercial facilities, there is a need for quality control of tissue culture
raised plants that are being produced at various laboratories. The Sugarcane Breeding
47
Institute has recently held a meeting involving various agencies to discuss and formulate
programmes to ensure quality seedling production. The need for ensuring genetic
uniformity of the multiplied plants was emphasized and a monitoring unit consisting of
scientists from National Research Centres, State Agricultural Universities and Sugar
Industry with R&D facility for tissue culture will monitor the activities.
Cultivated sugarcane varieties are complex species hybrids with 2n chromosome
numbers ranging from 100 to 120. Many varieties are chromosomal mosaics with
varying chromosome numbers in different cells of the tissues. This variability is seen
even in root tip cells and shoot tip cells just below the apical meristems. It is the apical
meristem that maintains the genetic integrity of the plants generation after generation in
crops like sugarcane, which are vegetatively propagated. Hence any multiplication
method should utilize the meristem as the basic material. The apical meristem is a group
of cells, situated at the extreme tip of the shoot or root in the shape of a dome. The shoot
meristem is covered by the developing leaf primordia. In sugarcane the apical dome can
be exposed by removing the developing leaf sheaths covering the growing point. The
apical meristem is also located in the auxillary buds on the canes. Hence either the apical
meristem located in the shoot apex or meristem located in the buds can be utilized to
initiate the culture.
THE METHODOLOGY
The protocols were standardized keeping in mind the sugar industry as the target
group. The methodology as standardised involve the following steps:
1. Collection and sterilization of actively growing healthy shoots, preferably during 90
to 180 days of crop growth.
2. Inoculation of shoot apices of 0.5 cm length containing the apical meristems in liquid
media on filter paper supports.
3. Transfer of the growing apices to modified MS (Murashige and Skoog) medium.
4. Production of multiple shoots by incorporating varying concentration of 6 BAP in the
medium.
5. Separation of individual shoots.
48
6. Rooting of plants in rooting medium.
7. Planting in polythene bags.
8. Maintenance of seedlings in bags upto 45 to 60 days.
9. Distribution to user agencies for field planting.
It is essential to examine the quality of cultures. It is desirable not to go above 8
to 10 cycles of multiplication from an apical meristem. So also the concentration of
6BAP should be adjusted to see that there is no over multiplication, leading to ball
formation, which will lead to poor quality of plants. It is essential to adhere to plant
production through axillary shoot formation and not through adventitious buds or through
somatic embryos since many sugarcane cultivars are chromosomal mosaics.
FIELD PLANTING
A spacing of 45 cms between plants and 90 cms between rows is found to be
optimum to achieve the best results. However, a wider spacing of 150 cms between rows
and 100 cms between plants were also found to be useful to reduce the number of plants
required for planting per hectare. The wider spacing increases the number of tillers and
allows good cane growth in many varieties. Establishment of the plants in the field is
above 95% if proper irrigation is given initially. With a synchronous tillering the crop
growth is uniform, free from all diseases and pests. The ratoons are excellent without
any gap and yields equal or better than the plant crop.
Critical studies on morphological characters of micropropagated and normally
propagated clones were carried out on several varieties. There were no changes in
botanical characteristics, except for an increase in tillering, slight reduction in stalk
diameter in the first generation and a few colour changes in some varieties. The genetic
stability of micropropagated plants was as stable as plants propagated through stem
cutting. In some varieties the frequency of colour changes was slightly more.
The canes produced by planting meristem-propagated plants can be regarded as
breeder seed in relation to the three-tier seed production programme. The canes can be
planted as two budded or three budded setts to raise the foundation seed. But it is
generally advised to produce polybag seedling through single budded setts so that the
49
seedlings can be distributed to farmers for producing certified seed by skipping the
foundation seed stage. This ensures rapid propagation and cost reduction. The
operational aspects can be worked out by individual factories to ensure proper
distribution and transport.
ADVANTAGES OF THE TECHNOLOGY FOR SUGARCANE
1.Through the micropropagation technique, the variety is multiplied without any genetic
change. Hence there should not be any difference in cane yield, quality, disease
resistance or pest tolerance as compared to the donor as it originally existed. However, in
practice, when seed produced through micropropagation system is used, an improvement
in yield to the tune of 8 to 10 t/ha and quality improvement of over 0.5% is noticed
compared to the crop raised through the farmers seed. This is due to the restoration of
original vigour of the variety when it is passed through a tissue culture cycle. In the case
of sugarcane it takes about 12 to 13 years by the time a new sugarcane variety reaches the
farmers hands. During the course of these years the variety could have undergone some
amount of deterioration due to various factors, mainly due to accumulation of cryptic
pathogens, leading to decline in vigour and in other economic traits. The tissue culture
cycle regains the original vigour and hence the observed improvement.
2. At the time of release of a new variety, the seed availability in research centres is very
limited. It takes about 4 to 5 years for a new variety to be commercially planted in the
required area of the factory. If the new clone is multiplied through the tissue culture
technology, it will be possible to cultivate the new variety commercially within two years
and can benefit from cultivating the new variety early.
3. In the conventional seed production programme the breeder seed plots are planted with
the heat-treated seeds. Heat treatment is not required in the case of micropropagated
breeder seed nurseries. The seed is free from disease organisms and pests.
4. Sugar industries transport huge quantities of seed material from one part of the country
to the other. This lead to spread of diseases and pests. Introduction of new varieties
through micropropagated plants ensures total protection against the introduction of new
diseases.
50
5. An effective varietal scheduling is possible if the multiplication programme is
carefully planned. In order to maintain a high recovery in the factory it is necessary to
develop three or four varieties with different maturity periods suitable for different soil
conditions and planting seasons. Production of quality seed through this programme in
the required proportion can help in achieving this most important component of cane
development.
6. Many excellent varieties run out of cultivation due to poor quality of seed. Replacing
the seed with micropropagated quality seed will increase the field longevity of well-
adapted varieties.
TECHNOLOGY TRANSFER AND DISSEMINATION
The Institute provides consultancy in establishing micropropagation facility and
also train the manpower in all aspects of micropropagation. Among the different stages
of micropropagation protocol, the maximum time is required for establishing sterile
cultures and initial multiplication through axillary shoot formation. Considering the
initial time lag and the need for ensuring the genetic stability of the plants, to help the
organizations, the Institute is providing basic cultures after culture establishment and
initial multiplication. This helps in saving of considerable time and ensures quality.
The micropropagation technology is emerging as a powerful technique for rapid
propagation of newly released varieties and quality seed production. Adoption of the
technology combined with other crop production technologies will help in exploiting
fully the genetic potential of newly emerging varieties and will also ensure the longer
field life of these varieties.
51
BIOTECHNOLOGY IN SUGARCANE IMPROVEMENT
N.V. NAIR
Biotechnology is defined as the use of living organisms, cells, subcellular
organelles and or parts of those structures, as well as molecules to effect biological,
chemical or physical changes (USDA-ARS, 1990). Biotechnology is a blend of several
disciplines which has emerged as a result of the significant advancements made in
different branches of science including genetics, microbiology, molecular biology,
biochemistry, developmental biology, cell biology, etc., since the later part of the 20th
century. These advancements contributed to the basic understanding of life and life
governing mechanisms, which were eventually utilized for manipulating biological
materials for the benefit of man, be it in agriculture, medicine, environment conservation
or process industry.
Sugarcane improvement through breeding is almost a century old and the
improved varieties produced at Sugarcane Breeding Institute largely sustained the
sugarcane agriculture and sugar industry in the country. The remarkable improvements in
yield and quality achieved during the early half of the last century slowed down during
the later part, as the yield levels tended to plateau over the years. This period also
corresponds with the rapid expansion in cane area, particularly in suboptimal and
marginal lands. The varietal requirements also became varied to suit the different agro-
climatic conditions and the disease/pest situations prevailing in the respective zones. The
present varietal needs are much more complex and varied than it was and require more
intensive efforts from the breeders to develop varieties with higher productivity by
adopting newer technologies. Biotechnology holds promise in this context as a powerful
adjunct to conventional breeding methods.
Important applications of biotechnology in sugarcane improvement had been in
three major areas.
1. In vitro techniques of cell and tissue culture.
2. Production of transgenic plants
3. Sugarcane Genomics
52
1. In Vitro TECHNIQUES
1. a. Creation of somaclonal variability
Methods to regenerate sugarcane plants from tissue culture was initiated at
Hawaiian Sugar Planters Association Experimental Station, during 1960s ( Nickell, 1964,
1977). Cytogenetic studies of the plants derived from callus culture showed variation in
chromosome number and associated morphological changes. Plants derived from cell or
tissue culture had been termed somaclones and the variations observed among the
somaclones are known by somaclonal variations. The advantages perceived of
somaclones are that they resemble the original source plant to a large extent, with
minute variations which can be beneficial at times. Thus minor modifications of a well
adapted variety could be achieved through tissue culture, while retaining most of its
positive attributes. Sugarcane somaclones with resistance to Fiji disease had been
reported by Krishnamurthy and Tlaskal (1974). Many sugarcane somaclones with
resistance to eye spot disease, but without any other detectable morphological variations
from the parent, had been isolated by Heinz et al, (1977). Variability for smut and rust
resistance had been obtained through callus culture in India (Sreenivasan et al, 1986,
1987). Improvement in agronomic characters also have been reported in somaclones and
some of the recent 'Co' releases like Co 92007, Co 92029, Co 93005, Co 94003, Co
94012, Co 94003, Co 95016, Co 99011 and Co 99012 are somaclones.
1.b. Sugarcane micropropagation
True to type plants can be regenerated from the meristematic tissues, which may
not show any genetic changes in relation to the parents. This technique had been widely
used for the rapid multiplication of commercial varieties and forms an important
component of the sugarcane seed programmes at present. Micropropagation has made it
possible to multiply new varieties very rapidly and make them available for cultivation in
a very short time. Apart from this, micropropagation is also useful in the rejuvenation of
the older varieties which shows varietal degeneration following years of continued
cultivation. A detailed discussion on the subject has been included elsewhere in this
manual.
53
1.c. In Vitro germplasm storage
One of the world collection of sugarcane germplasm is maintained by Sugarcane
Breeding Institute, at its Research Centre at Kannur. The year to year maintenance of the
germplasm in the field requires considerable amount of time and resources. Alternatively
germplasm can be conserved in vitro. In sugarcane, in vitro storage of germplasm was
conceived as a back-up for the field maintenance, to prevent probable loss of germplasm.
Methods were standardized for the in vitro storage of sugarcane germplasm in liquid
medium containing minimum nutrients (Sreenivasan and Jalaja, 1985). This protocol
required change of medium only once a year. Plants were stored for periods upto 3 years
using this technique, without any detectable cyto-morphological changes.
2. PLANT TRANSFORMATION
Transformation refers to the genetic changes brought about in an organism
through the introduction of foreign DNA. Transformation was first demonstrated by
Avery et al, (1940) in bacteria and is being routinely employed in experiments involving
micro organisms since then. Transformation experiments involving plant cells were
seriously pursued since 1980s and several techniques were developed for the
transformation of plant cells, their regeneration and stable expression of the transgenes.
By comparison, transformation technology provides a viable and speedy option for the
selective introduction of specific genes or gene complexes in crop plants, which
conventional hybridization and selection techniques will take several years to achieve.
Today plant transformation is a proven technology demonstrated in a large number of
crop species including sugarcane.
The basic requirements for plant transformation are the following.
2.a. Availability of the cloned gene of interest
Methods are now available to identify, characterize and isolate genes of interest
and clone them or synthesize them based on the sequence information. The mechanism of
gene expression also is fairly well understood now that the genes of interest with suitable
regulatory elements like promoters, enhancers etc. can be assembled to form a functional
gene. A typical gene construct will include a promoter, a coding sequence and a
terminating signal. Apart from the gene of interest, there also should be a selectable
marker that will enable us to pick out the transformed cells from among the
54
untransformed ones. This marker gene is usually an antibiotic resistance gene like
Kanamycin, which will prevent the proliferation of untransformed cells in a medium
containing Kanamycin or a visually scorable marker like fluorescence.
2.b. Availability of suitable methods for the delivery of DNA into cells
Once the genes of interest are identified and cloned, we should have a suitable
mechanism by which the genes can be placed inside the cell and got stably integrated in
the genome and expressed. Over the years several methods have been developed to
deliver DNA into the cells. This includes both physical as well as biological methods,
some of which are discussed here.
2.b.1. Electroporaton
This is a relatively simple procedure, in which the DNA uptake by cells is
achieved by creating pores on the cell membrane through the application of high voltage
electric current. The pores reseal on its own and will not interfere with the cell function.
Many types of tissues have been used for the electroporation, including meristem, callus,
embryos, seed etc. The tissue to be electroporated is placed in a buffer containing the
particular DNA of interest and a short charge of high voltage electric current is passed.
This will result in the pore formation, following which the DNA uptake will take place.
Though not widely adopted, stable transgenics in many crops including rice and
sugarcane have been produced using this technique.
2.b.2 Agrobacterium mediated transformation
This is one of the most widely used techniques in plant transformation, exploiting
the natural ability of the Agrobacterium to deliver a part of its DNA into the host cell and
thereafter to get it integrated into the host genome. This bacteria which causes the crown
gall disease in dicot plants carries a large plasmid known as 'Ti' (Tumour inducing)
Plasmid. On infecting a host plant, the bacteria transfers a small segment of its DNA (T-
DNA) carried on the Ti-plasmid to the host cells. Once inside, this fragment gets stably
integrated into the chromosome of the host cell and thereafter several genes carried on the
T-DNA encoding for the biosynthesis of growth regulators, auxins etc. are expressed and
their excessive production leads to uncontrolled cell proliferation and tumour formation.
The T-DNA also encodes for certain aminoacid derivative called opines, which are
utilized by the bacteria.
55
There are three key elements essential for the T-DNA transfer into the host cells.
These are
i. T-DNA border sequences:
The 24-25 bp direct repeats flanking the T-DNA ( known as the right and left
borders of T-DNA) are essential for the delivery of T-DNA into the host cell. Generally,
all the DNA present between these border sequences are delivered into the plant
chromosomes. By replacing some of the original sequences lying between the T-DNA
borders in the Ti plasmid, with the desirable gene sequences, a Ti-plasmid can be
developed, which on infecting the plant cells will deliver the newly introduced sequences
into the host chromosome.
ii. Virulence (vir genes)
These segments present in the Ti-plasmid are essential for cell infection, excision
of the T-DNA and subsequent integration of the T-DNA into the host chromosome.
iii. Chromosomal genes
Apart from the genes present in the Ti-Plasmid, some of the genes present on the
bacterial chromosome also are involved in the transformation process. They control the
recognition of the host and attachment of the bacteria to the host cells.
Agrobacterium generally infects only dicots, which was considered a limitation in
bringing about transformation in monocots. But by suitably modifying the bacterial
genome, it has been possible to achieve Agrobacterium mediated transformation in
important cereal crops like rice, maize etc.also.
2.b.3. Particle bombardment or Biolistic delivery
This is one of the more recent and widely adopted method for plant
transformation. In this method, microparticles of gold or tungsten coated with the specific
DNA of interest are accelerated to a high velocity using gas pressure or electric discharge
and directed to plant tissues using a particle gun, physically delivering the DNA into the
plant cells. The method allows any type of material ranging from embryos, anthers,
microspores, leaf, stem or apical meristem to be used for transformation. The exact
mechanism of DNA integration into the host genome is not clearly understood.
Multicopy integration of the DNA as well as fragmentation of the DNA due to the
physical force are possible, which is a limitation of this method.
56
Other methods used for transformation include PEG (Poly Ethylene Glycol)
mediated DNA uptake, Laser mediated transformation, Microinjection etc.
2.c. Proper Regeneration Method
The success of plant transformation experiments depend on the availability of
appropriate regeneration protocols by which, the transformed cells could be grown into a
complete plant. For most of the important crops regeneration protocols are available and
is not a serious limitation.
2.d. Transformation studies in sugarcane
Early experiments on sugarcane transgenics were carried out in Australia by
Bower and Birch during late 1980s. Transformation of callus through electroporation
could be achieved in sugarcane, but regeneration has not been possible (Rathus & Birch,
1992). The first gene of agronomic interest to be incorporated in sugarcane through plant
transformation was the bar gene, encoding for herbicide resistance (Chowdhary & Vasil,
1992). Bower and Birch (1992), reported sugarcane transgenics through particle
bombardment. Herbicide resistant transgenics were also reported by Gallo-Meagher and
Irvine (1995) and Subramanian et al, (1998). Transgenics of sugarcane incorporating bt
gene for borer resistance also have been reported (Fitch et al, 1996). Transgenics with
mosaic and cane grub resistance have been reported from Australia (Smith et al, 1999).
3. SUGARCANE GENOMICS
Molecular studies on sugarcane genome dates back to late 1980s, when RFLP
based genome analysis in sugarcane was initiated at the Cornell University with the
active support of HSPA Experiment Station, Hawaii and Copersucar, Brazil. With the
advent of PCR based markers, the molecular characterization of sugarcane became faster
and more widely adopted. Molecular markers are superior to the conventional
morphological markers in several ways. They are abundantly present in the genome, are
stably inherited in Mendelian fashion and their expression is environment independent.
More over, these markers can be detected at any stage in the development of the plant,
unlike morphological markers which are expressed only at a particular stage of
development. The important molecular markers widely used in sugarcane genomic
studies are:
57
3.a. Restriction Fragment Length Polymorphism (RFLP)
When the genomic DNA of an organism is treated with a restriction enzyme, the
DNA is cut into a large number of fragments. Each restriction enzyme has a recognition
site on the DNA, represented by a specific nucleotide sequence and the enzyme will cut
the DNA only at these sites. The distribution of DNA restriction sites vary between
individuals, with the result the size of the fragments obtained following restriction also
varies. This variation in the size of the restriction fragments is referred to as RFLP.
RFLPs are detected by hybridizing the enzyme digested genomic DNA with a labelled
probe of known sequence and is visualized by autoradiography. RFLP gives highly
repeatable results, but is laborious, expensive, requires large quantities of DNA and
involves radioactive detection. RFLP is a codominant marker.
3.b. Randomly Amplified Polymorphic DNA (RAPD)
This is a PCR (Polymerase Chain Reaction) based assay using a single random
primer, usually decamers. The primer binds to two sites on the opposite strands of the
DNA template and if these priming sites are within an amplifiable distance of each other,
the DNA segment lying between them will be amplified during thermal cycling. This is
essentially a thermal reaction involving 3 steps. In the first step, the reaction containing
the template DNA, the dNTPS, the random primer and the Taq DNA polymerase with the
required buffer is heated to 94°C, when the template DNA is denatured and the two
strands separate. In the second step, the reaction is cooled to ~35°C, when the primer will
anneal to the opposing DNA strands where there is complementarity. During the third
step the reaction is heated to 72°C, at which the Taq DNA polymerase will extent the
primer along the template DNA resulting in the synthesis of a new segment of the
template DNA. With repeated cycles, several copies of the DNA segment will be
produced which can be visualized following Ethidium bromide staining. The primer
binding sites will vary among the individuals, resulting in the variation in size of the
amplification products, thus contributing to the polymorphism. This method is relatively
simple, fast, requires very little DNA and involves no radioactivity. However the
technique is highly sensitive to experimental conditions and repeatability is relatively
low. RAPD is a dominant marker.
58
3.c. Amplified Fragment Length Polymorphism (AFLP)
AFLP is a dominant marker that combines the reliability of RFLP and the power
and versatility of the PCR techniques. AFLP involves restriction of the genomic DNA
with two restriction endonucleases, followed by ligation of site specific double stranded
DNA adapters to the fragments to generate DNA templates for amplification. Selective
amplification of the DNA fragments is achieved using suitable primers. The
polymorphism revealed by AFLP is far more than either RFLP or RAPD.
3.d. Microsatellites
Microsatellites or Simple Sequence Repeats (SSRs) are tandem repeats of small
DNA motifs ( eg: GACA GACA GACA GACA), of varying length. They are abundantly
found in the genome and can be characterized by using appropriate primers.
Microsatellites are highly polymorphic and are inherited in a codominant fashion.
Molecular markers have a variety of applications in the study of plant genomes.
They are widely used in genome mapping, finger printing of varieties and germplasm,
identifying markers associated with specific traits and in the study of phylogeny and
genetic diversity of crop plants.
3.e. Molecular markers in sugarcane
3.e.1. Genome mapping of sugarcane
Genetic maps define the physical organization of genes on the chromosomes and
they can help in the resolution of complex traits of economic importance and thus have
potential application in plant breeding programmes. Molecular mapping of Saccharum
genome using RFLP was initiated at Cornell University during 1989, with the active
participation from HSPA Experiment Station, Hawaii and Copersucar, Brazil. RFLP
mapping was attempted using cDNA and random genomic probes developed from
Saccharum as well as maize and other related grasses. Mapping population was derived
from a cross of the Saccharum spontaneum clone SES-208 (2n=64) x ADP 68 (2n=64; a
doubled haploid of SES-208). da Silva et al. (1993), reported the RFLP linkage map for
S.spontaneum, comprising of 216 loci, detected by 116 DNA probes and distributed over
44 linkage groups. At a density of atleast one marker every 25 cM interval, the coverage
of the genome was 86%. RFLP studies also suggested the autopolyploid nature of
S.spontaneum. Al Janabi et al. (1993) mapped 208 single dose PCR polymorphisms into
59
42 linkage groups using primers of arbitrary sequence. da Silva et al.,1995 reported a
linkage map of 64 linkage groups for Saccharum spontaneum (SES 208, 2n=64),
constructed using 208 single dose arbitrarily primed PCR markers, 234 single dose, 41
double dose and one triple dose RFLPs. This map had a predicted genomic coverage of
93% and an average interval of 6cM between the markers.
Genetic maps of S.officinarum and S.robustum also had been developed based on
a mapping population from the cross Louisiana Purple (S.officinarum) x Mol 5829
(S.robustum). Mudge et al. (1996) constructed a RAPD map of S.officinarum using this
population, which included 161 markers mapped on 50 linkage groups. Guimaraes et al.
(1999), reported a genetic map of Louisiana Purple with 341 SDMs (Single Dose
Markers) mapped on 74 linkage groups and that of Mol 5829 with 301 SDMs spanning
65 linkage groups, using AP-PCR, AFLP’s and RFLP’s. Molecular map of commercial
cultivars SP 701006 (D'Hont et al., 1994) and R570 (Grivet et al., 1996) also had been
reported.
3.e.2. Trait Specific markers
Molecular markers linked to important plant characters can be effectively used for
screening plant populations during different stages of breeding. Honeycutt et al. (1995),
reported DNA markers for quantitative characters like percent flowering, disease
susceptibility, stalk girth, cane tonnage and percent pols in a population derived from a
cross between S.officinarum and S.robustum. RAPD markers linked to fibre content in
Saccharum species had been identified by Msomi and Botha (1995). A simulated
selection using these markers resulted in a significant increase in the number of high fibre
clones in the selected progeny. Mudge et al., 1996 reported a RAPD marker linked to
eye spot disease in a population derived from S.officinarum X S.robustum cross. A RFLP
marker linked to rust resistance in the sugarcane cultivar R570 had been reported by
Daugrois et al., 1996. SCAR markers for sugarcane rust resistance in variety NCo 376
has also been identified by Barnes and Botha (1998).
3.e.3. Molecular fingerprinting of varieties and germplasm
Molecular fingerprinting has important applications in the context of plant variety
protection and biodiversity conservation. Fingerprints of 80 sugarcane progenies and two
parents could be established using 4 RFLP probes at HSPA Experiment Station. RAPDs,
60
Microsatellites and telomere motifs also had been used for the fingerprinting of sugarcane
clones (Harvey and Botha, 1996).
3.e.4. Genus and species specific markers
Interspecific hybridization of cultivated and wild species of Saccharum had been
the mainstay of all sugarcane breeding programmes. Hybridization of Saccharum with
related genera like Erianthus and Miscanthus also had been found to yield progenies with
higher productivity and better adaptability. Distant hybridization involving related
species and genera is difficult to perform and identification of the true hybrids from selfs
among the progeny is invariably difficult. Molecular markers had been found to be useful
in this context for the identification of genuine interspecific and intergeneric hybrids.
D'Hont et al, (1995) used PCR amplification of 5s ribosomal DNA spacer length
variations to identify intergeneric hybrids involving Erianthus. Genus specific repetitive
sequences (Besse and McIntyre, 1998; Alix et al., 1998) and Alu PCR (Alix et al., 1999)
also have been found to be useful in identifying hybrids involving Saccharum and related
genera.
3.e.5. Molecular markers in Saccharum phylogeny
Molecular markers have been found to be particularly useful in resolving complex
phylogenetical problems in Saccharum. D'Hont et al. (1993), reported closer relationship
between S.officinarum and S.robustum based on the study of mitochondrial DNA
variation. S.barberi and S.sinense showed similarities with the genome of S.officinarum,
indicating a possible S. officinarum origin. RFLP studies also showed that S.spontaneum
is genetically more diverse compared to other species of Saccharum ( D' Hont et al,1993;
Lu et al, 1994). Sobral et al, (1994), reviewed the phylogenetic relationship among 19
species of Saccharinae, based on the analysis of chloroplast restriction site mutations and
concluded that Saccharum, Narenga, Sclerostachya and Miscanthus belonged to a
monophyletic group, while Erianthus and Eccoilopus formed a separate group. A study
on Saccharum complex based on RAPD markers showed that the genetic diversity was
low in S.officinarum and high in S.sinense (Nair et al, 1999). Among the related genera,
Sclerostachya was found to be closer to Saccharum while Erianthus was found to be
highly divergent from Saccharum. Saccharum, Sclerostachya and Narenga formed a
closely related group while Erianthus was found to be highly divergent from them. A
61
study by Harvey and Botha (1996), on the genetic diversity of 26 clones of
S.officinarum, S.spontaneum and commercial hybrids using RAPDs and SSR’s revealed
80 % similarity among the DNA of commercial varieties. Harvey et al, (1994) also
reported low genetic diversity (10.27 to 28.18%) among 20 South African commercial
varieties, with most of the varieties showing nearly 80% genetic similarity. Nair et al,
(2002), estimated the genetic diversity among 28 Indian commercial varieties to be about
30% only, indicating a limited genetic base of the current commercial varieties.
Conclusion
Recent advances in biotechnology have contributed significantly to our
understanding of the sugarcane genome, providing greater opportunities for the
improvement of the crop through genetic manipulations. Molecular maps of different
species of Saccharum and varieties have been developed which will eventually lead to
saturated genetic maps of sugarcane with loci for important phenotypic traits mapped into
it. DNA markers tightly linked to important traits will enable breeders to select for these
characters with more precision, without scoring for the phenotype per se. The
introgression of wild genes from the related species and genera can be precisely
monitored using molecular markers, which will strengthen the base broadening
programmes. Sugarcane transgenics are a distinct possibility now, with several
transgenics incorporating disease, pest and herbicide resistance genes undergoing field
evaluations. Biotechnology is thus expected to provide greater precision and added thrust
to the sugarcane improvement programmes in the years to come.
References
Alix K, Baurens F.C, Paulet F, Glaszmann J.C. & D'Hont A. (1998), Isolation and characterization of a satellite DNA family in the Saccharum complex. Genome 41: 854-864
Alix K, Paulet F, Glaszmann J.C. & D'Hont A.(1999), Inter-Alu like sequences in Saccharum complex. Theor Appl Genet. 99: 962-968
Al Janabi S.M, Honeycutt R.J. & Sobral B.W.S. (1993), A genetic linkage map of
Saccharum spontaneum L. SES 208. Genetics 134(4): 1249-1260
Barnes J.M. & Botha F.C. (1998), Progress towards identifying a marker for rust resistance in Sugarcane variety Nco376. Proceedings of the Annual Congress - South African Sugar Technologists Association. 72:149-151
62
Besse P. & Mc Intyre C.L.(1998), Isolation and characterization of repeated DNA sequences from Erianthus spp. (Saccharinae : Andropogonae). Genome 41: 408-416
Bower R & Birch R.G.(1992). Transgenic sugarcane plants via microprojectile bombardment. Plant J. 2:409-416
Chowdhury M.K.V & Vasil I.K. (1992). Stably inherited herbicide resistant callus of sugarcane via microprojectile bombardment of cell suspension cultures and electroporation of protoplasts. Plant Cell Rep. 11:494-498
da Silva J, Sorrells M.E, Burnquist W.L. & Tanksley S.D.(1993), RFLP linkage map and genome analysis of Saccharum spontaneum. Genome 36:782-791
da Silva J, Honeycutt R.J, Burnquist W.L, Al-Janabi S.M, Sorrells M.E, Tanksley S.D. & Sobral B.W.S.(1995), Saccharum spontaneum L. ‘SES 208’ genetic linkage map combining RFLP- and PCR-based markers. Mol Breed 1:165-179.
Daugrois J.H, Grivet L, Roques D, Hoarau J.Y, Lombard H, Glaszmann J. C. & D’Hont A.(1996), A putative major gene for rust resistance linked with an RFLP marker in Sugarcane cultivar R570. Theor and Appl.Genet. 92: 1059-1064.
D'Hont A, Lu Y.H, Feldmann P. & Glaszmann J.C. (1993), Cytoplasmic diversity in sugarcane revealed by heterologous probes. Sugarcane 1: 12-15
D'Hont A.D, Lu Y.H, Le'on D.G.D, Grivet L, Feldmann P, Lanaud C. & Glazmann J.C.(1994). A molecular approach to unravelling the genetics of sugarcane, a complex polyploid of the Andropogoneae tribe. Genome 37: 222-230
D'Hont A.D, Rao P.S, Feldmann P, Grivet L, Faridi N.I, Taylor P & Glazmann J.C. (1995). Identification and charcaterisation of sugarcane intergeneric hybrids, Saccharum officinarum x Erianthus arundinaceus, with molecular markers and DNA in situ hybridisation. Theor. Appl. Genet. 91: 320-326
Fitch M, Chang V, Perlak F, Dela Cruz A & Moore P.H. (1996). Insect resistant transgenic sugarcane via particle bombardment. Proc. Int.Soc. Sugarcane Technol. XXII (2): 459-463
Gallo-Meagher M & Irvine J.E. (1995). Production of herbicide resistant transgenic sugarcane plants. Plant Genome III. Poster 64.
Grivet L, D’Hont A, Roques D, Feldmann P, Lanaud C. & Glaszmann J.C. (1996), RFLP mapping in cultivated sugarcane (Saccharum spp.): Genome organization in a highly polyploid and aneuploid interspecific hybrids. Genetics 142: 987-1000
63
Guimares C.T, Honeycutt R.J, Sills G.R. & Sobral B.W.S. (1999), Genetic maps of Saccharum officinarum L. and Saccharum robustum Brandes and Jew.Ex Grassl. Genetics and Molecular Biology 22:125-132.
Harvey M. & Botha F.C.(1996), Use of PCR-based methodologies for determination of DNA diversity between Saccharum varieties. Euphytica. 89: 257-265.
Harvey M, Huckett B.I & Botha F.C (1994). Use of the polymerase chain reaction (PCR) and random amplification of polymorphic DNAs for the determination of genetic distances between 21 sugarcane varieties. Proc. South African Sugar Technol. Association. 36-40.
Heinz D.J, Krishnamurthy M, Nickell L.G & Maretzky A. (1977). Cell, tissue and organ culture in sugarcane improvement. In: Reinert,J & Bajaja,Y.P.S (Eds). Applied and fundamental aspects of plant cell, tissue and organ culture. Springer Verlag, Germany. pp 1-17.
Honeycutt R, Sills G.R, Bridges W. & Sobral W.S. (1995), Association of molecular markers with quantitative traits in a cross between sugarcane (Saccharum officinarum L.) and S.robustum Brandes and Jesw.ex Grassl. Plant Genome II. The international conference on the status of the Plant Genome Research, San Deigo, USA. Final programme and abstract guide. pp.46.
Krishnamurthy M & Tlaskal J. (1974). FIji disease resistant Saccharum officinarum Var. Pindar sub clones from tissue culture. Proc. Int. Soc. Sugarcane Technol. XV:130-137
Lu Y.H, D'Hont A, Walker D.I.T, Rao P.S, Feldmann P. & Glaszmann J.C. (1994),
Relationships among ancestral species of sugarcane revealed with RFLP using single-copy maize nuclear probes. Euphytica 78:7-18.
Msomi M. & Botha F.C. (1995), Identification of putative molecular markers linked to the fibre trait. International Plant Genome Conf. III Abstracts:pp 27.
Mudge J, Anderson W.R, Kehrer R.L. & Fairbanks D.J. (1996), A RAPD genetic map of Saccharum officinarum. Crop Science 36: 1362-1366.
Nair N.V, Nair S, Sreenivasan T.V. & Mohan M. (1999), Analysis of genetic diversity and phylogeny in Saccharum and related genera using RAPD markers. Genetic Resources and Crop Evolution. 46: 73-79.
Nair N.V, Selvi A, Sreenivasan T.V and Pushpalata K.N. (2002). Molecular diversity in Indian sugarcane cultivars as revealed by Randomly Amplified DNA polymorphisms. Euphytica ( Under Print).
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Nickell L.G. (1964). Tissue and cell culture in sugarcane: Another research tool. Hawaiian Planter's Record. 57: 223-229.
Nickell L.G. (1977). Crop Improvement in sugarcane: Studies using in vitro methods. Crop Sci.17: 717-719
Rathus C & Birch R.G. (1992). Stable transformation of callus from electroporated sugarcane protoplasts. Plant Sci. 82: 81-89.
Smith G, Joyce P.A, Nutt K.A, McQualter R.B, Taylor G.O and Aslopp P.G. (1999). Evaluation of transgenic sugarcane plants engineered for resistance to mosaic and cane grubs. Proc Int. Soc. Sugarcane Technol. XXIII (2):
Sobral B.W.S, Braga D.P.V, LaHood E.S. & Keim P. (1994), Phylogeneti analysis of chloroplast restriction enzyme site mutations in the Saccharinae Griseb. subtribe of the Andropogoneae Dumort. tribe. Theor Appl Genet 87:843-853.
Sreenivasan,T.V. & Jalaja N.C.1985.In vitro sugarcane germplasm storage.Sugarcane1: 1-2
Sreenivasan J, Sreenivasan T.V, Alexander K.C & Madhusudhana Rao M. (1986). Somaclonal variation for smut disease (Ustilago scitaminea Syd.) resistance in sugarcane. Proc. National Symp. Recent Advances in Plant Cell and Tissue Culture of economically important plants. Osmania University, Hyderabad.
Sreenivasan J, Sreenivasan T.V & Alexander K.C.(1987). Somaclonal variation for rust resistance in sugarcane. Indian J. Genet. 47 (2):109-114
Subramanian N, Sridhar V.V, George Thomas, Hemaprabha G & Tripathi, B.K. (1998). Expression of a transferred herbicide resistance gene in a sugarcane cultivar. Proc. 60th Ann. Con. Sugarcane Technol. India. (Agrl. Section) 34-39.
USDA-ARS, 1990. Solving agricultural problems with biotechnology, Program Aid 1445.
65
CANE AGRONOMY FOR WIDE ROW SPACING
P. GOPALASUNDARAM AND C. KAILASAM
Crop production aims at efficient harvest of solar energy through crop plants,
which in turn depends upon the efficiency of light interception and its utilization. Higher
efficiency of light interception could be achieved through rapid development of leaf area
index (LAI) and maintaining the optimum LAI for a longer duration. Plant population
and crop geometry have a dominant influence on LAI and light interception. Population
defines the size of area available to individual plants or the number of plants per unit
area, whereas crop geometry defines the shape of area available for individual plants or
the pattern of distribution of plants over the ground.
Attempts to work out the optimum row spacing for sugarcane to realize higher
yields have probably been made ever since sugarcane became a commercial plantation
crop. Shunmugasundaram and Venugopal (1979) after reviewing the sugarcane spacing
trials in India concluded that the optimum row spacing for different locations varied from
60 to 105 cm. As the environmental adversities of the locations increase, the optimum
row spacing narrowed down to a minimum of 60 cm. For high biomass yield, narrow
row spacing has been found beneficial (Lipinsky et al., 1978; 1979). Irvine and Benda
(1980) concluded that a higher yield under closer spacing is due to an exponential
increase in stalk population despite a linear weight decrease. A decrease in cane diameter
with crowding is also obvious. A high cane yield from close spacing is also associated
with a high biomass production.
Kanwar and Sharma (1975) studied the effect of five inter row spacings (60, 90,
120, 150 and 180 cm) on tiller mortality, stalk population and cane yield of the sugarcane
variety CoJ 46 (midlate variety with medium thin cane and erect habit) under sub-tropical
conditions. The results showed that tiller population was higher in closer spacings than
in wider spacings and the narrowest spacing (60 cm) recorded the highest population.
Tiller mortality was significantly reduced as the inter row spacing increased. Wider
spacing also produced thicker canes compared to narrow spacing. The cane yield at 60,
66
90, 120 and 150 cm row spacings were on par although 180 cm spacing gave lower yield
(Table 1).
Table 1. Effect of inter-row spacing on sugarcane ( CoJ 46)
CharacterRow spacing (cm) CD
(5%)60 90 120 150 180
a. Plant crop
No. of tillers( '000s / ha)
298.0 229.9 225.9 205.2 174.6 35.6
Stalk population( '000s / ha)
133.1 130.9 118.4 114.1 101.4 9.1
Tiller mortality (%)
55.3 43.1 47.6 44.4 41.9 -
Cane thickness ( cm )
1.85 1.87 1.90 1.90 2.00 NS
Cane yield (t / ha )
86.0 86.9 86.2 78.9 69.7 7.7
b. Ratoon crop
No. of tillers( '000s / ha)
310.6 225.3 230.7 203.3 172.4 30.6
Stalk population( '000s / ha)
117.2 116.8 116.6 116.6 98.2 8.6
Tiller mortality (%)
62.3 48.2 49.5 42.7 43.0 -
Cane thickness ( cm )
1.83 1.98 2.03 1.98 1.99 NS
Cane yield (t / ha )
61.1 59.6 61.3 65.7 55.2 NS
Source: Kanwar and Sharma (1975)
67
The drawbacks of narrower spacing are the high cost of seed cane and difficulties
in carrying out cultural practices and harvesting. Freeman (1968) expressed the
apprehension that the increased cost of cultivation may negate the gains achieved under
narrower spacings. Hunsigi (1993) has discussed the row spacings adopted under
commercial cultivation in the sugarcane producing areas of the world. The row spacings
range from 0.6 m to 2.4 m. In areas where mechanized cultivation is practiced, the row
spacing is wider ( > 1.2 m ) while narrower row spacings (0.6 m - 1.2 m) are adopted in
countries where human labour is extensively used for the cultivation of sugarcane. It is
therefore logical to assume that wider spacings were necessitated by mechanized
cultivation.
In India, harvesting of sugarcane is being done at present by using human labour.
As this field operation involves too much of drudgery, the availability of human labour
for harvesting is gradually dwindling. In addition, the labour is also becoming very
costly. Therefore, development of a mechanical sugarcane harvester suitable for Indian
conditions is the need of the hour. Wider row spacing is a pre-requisite for using
mechanical harvesters. M/s. Sakthi Sugars, Appakudal, Erode District, Tamil Nadu have
introduced a mechanical cane harvester from Australia (Case Austoft). For using this
machine, the sugarcane needs to be grown adopting a row spacing of 1.5 m (5 feet) which
is popularly referred to as wide row spacing. If wide row cane cultivation is done
adopting the management practices of conventional 90 cm row spacing, the cane yield
may be reduced. Hence it is necessary to adapt the management practices to maintain
cane yield under wide row spacing on par with conventional 90 cm row spacing.
Varietal selection plays a pivotal role in the success of wide row spacing.
Considerable differences in the response of sugarcane varieties to row spacing have been
reported. An experiment was conducted at Sugarcane Breeding Institute, Coimbatore to
study the performance of 10 sugarcane varieties under wide row spacing compared to the
conventional 90 cm spacing. The results indicated that varieties Co 62175, CoC 85061,
Co 8122 and Co 86032 recorded higher stalk population under wide row spacing,
whereas Co 87025 had the lowest stalk population due to extremely poor tillering.
Varieties Co 86032, CoC 671, Co 62175 showed a tendency to lodge under wide rows,
68
while CoC 85061, Co 8122 and Co 6304 remained erect (Sugarcane Breeding Institute,
1998). In general, the variety Co 86032 performs well under 150 cm wide row spacing.
A seed rate of 75,000 two budded setts per hectare, which works out to 6.75 setts
per metre length of row, is being adopted for sugarcane under the normal row spacing of
90 cm. When we adopt the above seed rate of 6.75 setts per metre length in wide rows,
there is a possibility of yield reduction because of lower stalk population per hectare.
However, it has been well established that tiller mortality is substantially lower and a
higher percentage of shoots survive to become millable canes under wide rows. Hence, it
may not be necessary to increase the seed rate to 11.25 setts per metre row to maintain
the seed rate of 75,000 setts per hectare. Increase in the average weight of cane at wide
row spacing has also been observed in several experiments. It is therefore suggested that
the optimum seed rate for wide rows may be around 9 setts per metre row length (60,000
setts/ha).
When the seed rate per unit length of row is increased, it may not be possible to
plant the setts in single rows in each furrow as practiced for 90 cm row spacing. The
setts may have to be placed either diagonally across the furrows or in double lines by
widening the furrows. This will make available more space for the germinating shoots
and facilitate higher tillering and better tiller survival.
At Sakthi Sugars, Appakudal, wide row spacing of 1.5 m (5 feet) was compared
with conventional spacing of 75 cm (2.5 feet) with the variety Co 86032. The seed rate
adopted for wide row spacing was 50,000 two budded setts/ha as against 1,00,000 two
budded setts used for 75 cm spacing. The data on quantitative characters recorded are
given in Table 2.
69
Table 2: Quantitative parameters of cane under wide row spacing compared to
conventional spacing
Sl.
No.
Quantitative characters Wide row spacing
(1.5 m)
Conventional
spacing (75 cm)
1. No. of tillers per hectare at 90 days 2,70,000 4,14,000
2. No. of millable canes per hectare at
harvest
1,05,000 1,20,000
3. Cane height (cm) 430 322
4. Cane diameter (cm) 2.64 2.35
5. Number of internodes per cane 31 29
6. Single cane weight (kg) 1.98 1.52
7. Cane yield (t/ha) 208 182
Source: Nagendran (1999)
At Sugarcane Breeding Institute, Coimbatore, sett placement patterns in wide
rows was studied with uniform seed rate of 75,000 two budded setts/ha in the variety Co
86032. The dual row planting (setts placed in two rows, 20 cm apart in the widened
furrow bottom) gave significantly higher cane yield (123.3 t/ha) than single row planting
in wide row (114.7 t/ha) or 90 cm spacing (99.3 t/ha) (Sugarcane Breeding Institute,
2000a).
In another experiment at Sugarcane Breeding Institute, Coimbatore, three seed
rates (75,000, 60,000 and 45,000 two budded setts/ha) were studied under wide row
spacing in the variety Co 86032. Soybean was also raised as an intercrop. The cane
yield obtained was 107.0, 104.6 and 96.8 t/ha in the seed rates, 75,000, 60,000 and
45,000/ha respectively as compared to 110.0 t/ha in the control (90 cm row spacing and
75,000 setts/ha). The study indicated that a seed rate of 60,000 setts/ha would be
sufficient for wide row planting (Sugarcane Breeding Institute, 2000b).
Prabhakar (1999) also compared the performance of the sugarcane variety Co
86032 under wide row spacing (150 cm row spacing and 60,000 setts/ha) and normal row
70
spacing (90 cm row spacing and 75,000 setts/ha). The cane yield obtained was almost
same in both situations, 119.1 t/ha under wide row and 119.8 t/ha under normal row.
The studies conducted on fertilizer and irrigation requirements of sugarcane under
wide rows and normal rows indicated that these do not change between the two situations
as the yields obtained are comparable.
The availability of large interspace between the wide rows facilitates the use of
power tillers and other small machinery for operations like weeding and earthing up. In
addition it is very easy for the human labour to move inside the field for operations like
trashing, plant protection, guiding irrigation water etc.
It has also been reported that when sugarcane is grown adopting closer row
spacing, it takes about three months for 'closing in' of the canopy while it takes longer
time under wide row spacing. The availability of more space and sunlight for a longer
duration in the early phase of sugarcane under wide rows also facilitates growing of
intercrops without any adverse effect on sugarcane.
REFERENCES
Freeman, K.C. 1968. Influence of row spacing on yield and quality of sugarcane in Georgia. Agron. J., 60: 424-425
Hunsigi, G. 1993. Production of Sugarcane - Theory and Practice. Springer-Verlag, Berlin, pp. 57
Irvine, J.E. and G.T.A. Benda, 1980. Sugarcane spacing II. Effect of the spacing on the plant. Proc. Int. Soc. Sug. Technol., 17: 357-366
Lipinsky, E.S., S. Kresowich, T.A. McClure and W.T. Lawhon, 1978 and 1979. Annual Reports (1978 and 1979) on Fuels from sugar crops to the U.S. Department of Energy by Battelle's Columbus Laboratories
Nagendran, K. 1999. Mechanization programme in Sakthi Sugars. In : Souvenir, National Workshop on Mechanization of Cane Cultivation. 25 April, 1999. Sakthi Sugars, Appakudal, Erode Dt., Tamil Nadu
Prabhakar, C. 1999. Management practices for intercropping of soybean in wide row sugarcane. M.Sc.(Ag.) Sugarcane Production Thesis. Sugarcane Breeding Institute in collaboration with Agricultural College and Research Institute, TNAU, Coimbatore
71
Shunmugasundaram, S. and Venugopal, 1979. Row spacing, sett rate and population control in relation to cane and sugar yield of sugarcane - A review. Indian Sug., 28(10) : 1-9
Sugarcane Breeding Institute. 1998. Wide row spacing. In : Annual Report for 1997-98, pp. 32. Sugarcane Breeding Institute, Coimbatore
Sugarcane Breeding Institute. 2000a. Wide row spacing. In : Annual Report for 1999-2000, pp. 39. Sugarcane Breeding Institute, Coimbatore
Sugarcane Breeding Institute. 2000b. Input requirement and economics of wide row spaced sugarcane with soybean intercrop. In : Annual Report for 1999-2000, pp. 41. Sugarcane Breeding Institute, Coimbatore
72
IMPROVING SUGARCANE RATOON PRODUCTIVITY
B. SUNDARA
Ratoons account for sizeable share in the total production of sugarcane in India.
In some of the major cane growing states like Uttar Pradesh, Maharashtra, Gujarat and
Haryana, more than 55 per cent of the total cane area usually remains under ratoons,
whereas in certain parts like Assam, ratoons account for more than 80 per cent of the area
under cane. Ratooning is an essential part of sugarcane cultivation since ratoons offer
several advantages: Ratoons are more profitable as the cost of cultivation is less by about
25 per cent from the plant crop because of the saving in the cost of seed material and land
preparation. Ratoons mature early by about a month and hence are useful for early
crushing. Besides, ratoons are generally rich in juice quality. Though many ratoons are
common in some of the sugarcane growing countries like Mauritius, Hawaii and Cuba,
only one or two ratoons are taken in our country. Ratoon yields are poor, the yield gap
between plant and ratoon crops being as wide as 30-40 per cent in the sub-tropical cane
belt and 10-20% in the tropical belt. Ratoon yields could be equaled or even improved
over the plant crops by proper management practices.
Ratoon management should aim at inducing early sprouting and stubble
establishment, early tiller production, low tiller mortality with higher millable canes and
early initiation of fresh root system.
Stubble establishment and quick sprouting depends on several factors like variety,
age of the plant crop at harvest, pests and diseases. Varieties manifest variable stubble
establishment ability and deterioration. Disease affected crop also affects stubble
sprouting. For this, spraying of organomercurial compounds like Emisan, Bavistin, have
been found useful. Time of harvest has great bearing on stubble sprouting. If the cane is
harvested in the rainy months, stubble deterioration will be much higher due to fungal
infestation. A spray of mercurial compounds may be required. Ratoons are more
susceptible to aberrant climatic conditions. Stubble establishment is poor in the early
harvested (Nov - Dec) cane in the sub-tropical India due to low temperature. Studies
have indicated that cane yields are better under trench planting than under flat planting.
73
To enhance sprouting, polythene mulch was found useful, but from the large scale
adoption view point, this does not appear promising due to high cost involved. Spraying
of growth promoters like gibberellic acid (GA3) and ethrel have been found to enhance
survival of sprouts under the adverse climatic conditions of north India. Other chemicals
like cycocel, indole buteric acid (IBA) and indole acetic acid (IAA) have also been found
useful. In the tropical region, however, the problem of low temperature does not arise.
Sprouting is generally better, provided the stubble condition is good and moisture and
nutrients are not limiting. At Mandya, irrespective of the variety, plant crop ratooned in
February gave better yield and quality compared to August or November harvests.
Tiller production is early and profuse in ratoons. This can be achieved and
sustained by nitrogen and phosphorus applications, ratooning in warmer months and
spraying certain growth promoters.
There is some time lag between the decay of old root system and the formation of
the shoot roots in the ratoons. This time lag varies between 4 to 6 weeks depending on
the variety, climatic conditions and cultural practices. Ratoons cannot stand moisture
stress particularly in the early stages of growth and therefore require irrigation at frequent
intervals. For proper root development, application of nutrients especially N and P, near
the stubble is essential. Shoots of the successive ratoons originate at higher level than the
plant crop. Therefore ratoons have less anchorage and are prone to lodging. Deep
stubble shaving is useful to get shots from the lower level and to have root system at a
deeper level which would be better equipped to draw nutrients and water from the deeper
soil layers. Stubble shaving also helps in eliminating top unhealthy buds.
Soil compaction is an important problem in ratoons; bulk density increases and
soil aeration is affected. This leads to several complications like poor root development
and hence uptake of nutrients and water. Digging the inter spaces, off bearing and sub-
soiling operations would help overcome this problem.
One more serious problem in sugarcane ratoons is the occurrence of gaps, which
when exceeds 20 per cent have caused significant yield reductions. Studies have shown
that gap filling the ratoons with pre-germinated setts raised from single bud setts in
polythene bags ensure quick establishment, higher tiller and stalk populations.
74
Ratoon response to applied nitrogen is far less than the plant crop. Studies at
Anakapalle (AP) have shown that ratoon required double the dose to produce the same
response as that of plant crop. Thus N-use efficiency in ratoons is poor. However, in
deep well managed soils with high organic matter content, good responses have been
observed. N-use efficiency could be improved by incorporating legume residue. By this
method, about 20 per cent increase in N-use efficiency has been noted at Mandya.
Legumes that could be used are sunnhemp, french beans and green gram.
In the ratoons, there is temporary blocking of nutrients due to microbes while
decomposing crop residues (old roots and stubbles). Coupled with this, there is some
time lag before the new roots are formed. Hence the ratoons suffer due to want of
nutrients. Ratoon chlorosis therefore occurs widely. Ferrous sulphate application along
with urea would help the crop. Because of the temporary tie-up and less N-use efficiency
of the ratoons, usually ratoons need slightly more nitrogen. Several studies in the tropical
India have shown that about 25 per cent more N is required for ratoons.
Time of manuring is of vital importance for better establishment of ratoons. In
plant crops, manures are applied before 4 months, while in ratoons, it is important to
complete manuring by about 2 months. Several studies in the sub-tropical region have
indicated that application of manures in two equal splits - half immediately after the
harvest of plant crop and the remaining half when the monsoon breaks is ideal. In the
tropical belt, it has been indicated that application of N and K is best done at 30 and 60
days of the harvest of the plant crop. Phosphorus however has to be applied as basal.
Some studies have favoured first top dressing at the time of second irrigation, i.e. about
8-10 days after the harvest of plant crop. From extensive studies of this author, the best
manurial schedule for ratoons is: Full P + 1/3 N + 1/3 K at ratooning followed by 1/3 N
+ 1/3 K at 30 and 60 days later.
Popularisation of a variety depends to a great extent on its ratooning ability. For
example, CoC 671 performed better as plant crop, but not as ratoon in a number of
locations. Such varieties need special ratoon management practices.
Ratoons are more prone to moisture stress due to their shallow root system.
Therefore copious irrigation after the harvest of plant crop is required. Irrigation at 50
75
per cent soil available moisture depletion during the formative and grand growth phases
and at 75 per cent depletion in the maturity phase has been found useful.
Multi ratoons are possible only under certain situations like deep alluvial soils, in
areas free from pests and diseases and in soils rich in organic matter. With appropriate
variety, manurial practice, addition of organic manures and trash incorporation multi-
ratoons could be raised. In acid soils, liming is required for better ratooning.
In ratoon fields, trash management is an important aspect. Several studies have
proved that trash mulching is better than trash burning. Trash also could be composted in
situ using decomposing microbial culture.
Thus ratoons forms a significant component of sugarcane production. By proper
management, yields could be improved. Management practices include proper time of
harvest of the plant crop, stubble shaving, off-barring, digging the interspaces, gap filling,
early manuring and adequate irrigation. Special efforts are required in sub-tropical belt to
establish the stubble crop.
REFERENCES
Hunsigi,G.1985. Ratoon cane:some recent innovations. Maharashtra Sugar10(9): 19-44
Misra, A. and P.S. Mathur, 1983. Ratooning sugarcane in India - retrospect and prospect.
Indian Sugar Crops Journal. July - Sept.,1983. pp. 1-4
Parthasarathy, S.V. 1972. Sugarcane in India, KCP, Madras
Plucknett, D.D., J.P. Evenson and W.G. Sanford, 1970. Ratoon cropping. In: N.C.
Brady (Ed.) Advances in Agronomy, Academic Press, New York, 22: 285-330
Sundara, B. 1987. Ratoon management. In: K. Mohan Naidu and S. Arulraj (Editor),
'Sugarcane Technologies', pp. 28-36. Sugarcane Breeding Institute, Coimbatore
Sundara, B. 1998. Sugarcane cultivation: Vikas Publishing, New Delhi. 302 p.
Sundara, B., Sankaranarayanan, P. and Batcha, M.B.G.R. 1992. Varietal characteristics
affecting ratooning potential of sugarcane. Sugarcane, No.6: 1-4
76
COST MANAGEMENT IN SUGARCANE PRODUCTION SYSTEMS
B. SUNDARA
The cost of production of sugarcane is increasing year-by-year which is evident
by the increasing statutory minimum price of cane (Table 1). Therefore, sugarcane
production systems are becoming less remunerative to the farmers. The sugar factories
have to pay more for the raw material. Therefore cost of sugar production is increasing
and most factories report less profits and many are even becoming sick due to heavy
losses particularly in the Cooperative Sector. The Indian Sugar is reported to be costlier
than the sugar produced elsewhere in the world and this is why there is problem of export
of sugar beyond the quota limit. In many sugarcane growing areas often farmers have
been switching over to other more remunerative crops which are more input-productive
than sugarcane. This puts extra strain on the factories to register adequate cane area.
Thus there is urgent need to effect economy and improve profits both for the sugarcane
farmers as well as millers.
Table 1: Statutory minimum price of cane during different years linked to 8.5% sugar recovery
Year Statutory minimum price(Rupees per quintal)
1980-81 13.00
1985-86 23.00
1995.-96 42.50
1999-2000 56.10
COST REDUCTION
Importance of cost reduction to any production system is quite vital for its
survival. This is equally true to agricultural systems. Sugarcane production systems
being commercial oriented with both producers (farmers) and consumers (millers) being
interested in higher profits, cost reduction and management becomes specially important.
77
Once the costs are saved they should be controlled at the low level until some
methods of reducing them still further is worked out. There should be constant
endeavour to increase the difference between the revenue received and costs incurred i.e.
positive difference to justify continuation of the production system. This should satisfy
both the farmers and factories. Farmers need not worry about profitability by switching
over to other agricultural systems or enterprises. Cost reduction can also help the sugar
mills pay less to the raw material and produce sugar at economic rate and sell sugar
abroad at competitive price if not supported by export quotas. The key to cost reduction
could be intensive and logical thinking and application of potential cost reduction
technologies.
COST REDUCTION TECHNIQUES AND STRATEGIES
No universal cost reduction technique could be suggested for reduction of cost in
sugarcane production systems as there are wide variations in the practices followed in
different agroclimatic regions as well as within a factory operational area itself.
Therefore, the intention should be to understand the strategies and concepts and
techniques which should be planned, organized, tested and implemented. It is really not
feasible to quantify precisely the savings. It depends upon the effectiveness of the
technology and thoroughness of its application by the farmers in individual growing
situation or production system.
There could be three basic approaches for cost reduction or improve profitability.
They are:
Approach 1 : Reduce input cost without affecting productivity
Approach 2 : Improve productivity without extra cost
Approach 3 : Improve productivity with extra cost; but the extra cost
must be less than the extra returns, i.e. with higher
marginal benefit cost ratio (MBCR)
The Approach 1, implies application of certain low cost technologies whereby
basic cost elements such as seeds, labour, water, few other inputs like fertilizers,
pesticides etc. are economized.
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In Approach 2, we aim at improving the input productivity like improving labour
use efficiency, fertilizer use efficiency, water use efficiency, etc. Also, all wastages of
inputs are minimized by appropriate technologies.
In Approach 3, the aim is to bring about long lasting improvements in the
production system with additional inputs or expenditure that will ultimately lead to
productivity improvements.
COST REDUCTION AREAS
To understand the areas of cost reduction in sugarcane production systems, it is
essential to know the components of cost of production or the cost structure. This author
has been working out the cost of cultivation of sugarcane for the past many years, mainly
to teach postgraduate students of sugarcane production course. As per the cost analysis
done during 1996, the total variable cost of cultivation (TVC), was around Rs. 48,000 for
a plant crop at Rs. 36,000 for a ratoon crop (Table 2). The cost structure analysis (Table
3) indicated that the human labour cost accounted for the biggest component of the TVC,
around 45 per cent for plant crop and 57% for ratoon crop. The next items of cost were
seeds and fertilizers that accounted for around 14 per cent each of the TVC.Transport was
another important item of cost, particularly when the distance is more.
Table 2: Economics of sugarcane cultivation*
Particulars Plant Ratoon
Cane yield (t/ha) 130 110
Gross returns (Rs./ha) 54,500 71,500
Total Variable Cost (Rs./ha) (Cost A) 47568 35631
Total Cost (Rs./ha) (Cost C) 67954 50901
Net Returns (Rs./ha) (On Cost A) 36932 35869
Net Returns (Rs./ha) (On Cost C) 16546 20599
Cost/tonne (Rs.) (On Cost A) 365.91 323.92
Cost/tonne (On Cost C) 519.58 462.74
Input/Output (On Cost A) 1.78 2.01
Benefit/Cost (On Cost C) 1.24 1.40
*Tamil Nadu, under optimum package of practices, cane price 650/t 1996
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Table 3: Cost structure in sugarcane cultivationS.No Input % TVC
Plant Ratoon
1. Human labour including contract harvest labour 45 572. Machine labour includes transport 17 113. Seeds 14 34. Manures & Fertilizers 14 195. Pesticides 4 46. Interest on working capital 6 7
100 100
From the above cost structure analysis, it is evident that cost reduction strategies
should aim at economizing labour use, seed cost, fertilizer cost and transport cost.
EFFICIENT USE OF BASIC COST ELEMENTS
In sugarcane production, the basic cost elements are labour, inputs mainly seeds
and fertilizers. This should go hand-in-hand with elimination of all wastes in the input
use down the production system. All excess uses should be eliminated. For example,
there is excess use of seeds and fertilizers particularly nitrogen and also irrigation water.
LOW COST TECHNOLOGIES
The low cost technologies available in sugarcane cultivation are indicated below:
No. Low cost technologies Objective
1. Spaced transplanting technique (STP)
To economize seed cost
2. Polybag seedling transplanting technology
3. Single bud sett direct planting
4. 'Chip bud' seed technology
5. Quality seeds
6. Machines and labour saving implements -
developed at IISR, Lucknow and elsewhere
To reduce labour cost To improve labour productivity
7. HerbicidesTo reduce labour cost and cost on pesticides8. Need based pesticide usage
9. Biofertilizers (Azospirillum, Azotobacter, Acetobacter, Phosphobacteria)
To economize cost on manures and fertilizers
10. Crop residues (trash) and by products (pressmud)
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It is difficult to say how much cost reduction is possible through each of these
technologies. Because, the extent of cost reduction depends upon the effectiveness of the
technology under different growing situation as well as the effectiveness of its
application. However, various seed technologies mentioned can bring about two-thirds
savings in the cost of seeds. Biofertilizers and herbicides are the potential means of cost
reduction provided we are sure of the quality of the products used. Labour saving
devices and implements may need refinement and modifications for different growing
situations, particularly soil types and cultivation systems followed. But they are potential
means of cost reduction and may become a necessity due to labour shortages increasingly
felt, particularly during peak periods of operation such as planting and harvesting. Partial
mechanization should greatly help improve profits.
COST-REDUCTION PRODUCTIVITY CONCEPT
Cost reduction here embraces unit cost reduction by the increase in productivity
i.e.increase in output i.e. cane yield (or rate or output for a given expenditure). The basic
farm productivity concept is that profits are directly related to productivity. It means high
efficiency which results in low costs and therefore, maximum profits. In fact,
productivity is a measure of effectiveness of the production systems. Higher productivity
with even extra cost is worth, if the extra cost involved gives higher productivity and thus
profits. For example, a 5% increase in the cost, if can yield 10% higher productivity
then, it is worth aiming.
Improving productivity per unit labour, per unit input (seed, fertilizer, irrigation
water) should be aimed.
To improve labour productivity, it is essential to employ labour saving devices
and means as indicated. For example, labour requirement can be reduced by the use of
sett cutting machine, planters, use of herbicides and harvesters, etc.
Labour management improves the labour productivity, this includes, reasonable
targets to labourers, prompt wage payment, medical help and transport provision.
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LONG-TERM PRODUCTIVITY IMPROVEMENT STRATEGIES
Improving productivity and sustaining the same over a long period of time should
be an important strategy in cost management approaches. This should involve, soil
health improvements, particularly, elimination of problems such as salinity, alkalinity and
waterlogging; micronutrient deficiency etc. In the considered opinion of the author, there
is specific need to improve drainage in several of the canal irrigated tracts. Drainage
improvements in several areas can help improve productivity by 10-15 tonnes per hectare
in such areas.
VARIETAL APPROACH TO COST REDUCTION
Newer sugarcane varieties better in yield and rich in sucrose are being released by
the Sugarcane Breeding Institute and other State Agricultural Universities. Their
appropriate usage by proper varietal scheduling would help improve yields and
recoveries.
In the productivity improvement and cost management, sugarcane nursery
programme has a definite say. Quality seeds add to higher yields. Periodical seed
renovation through techniques like heat therapy or meristem culture need to be followed.
ROLE OF RATOONS IN COST REDUCTION
Sugarcane ratoons account for 40-50 per cent of the total cane area in the country.
But their contribution to total production of cane is around 35 per cent which means their
productivity is lower. Therefore, one of the major cost management areas is to improve
ratoon productivity. In improving ratoon productivity, important considerations are use
of varieties with better ratooning potential, proper and timely manuring, use of trash and
organic manures. By appropriate ratoon management, it is possible to improve ratoon
yields substantially.
Attempts to increase the number of ratoons or 'multiratooning' should also help
reduce cost per crop in the sugarcane production system. Particularly, there could be
huge saving in the labour and seed costs. As indicated in Table 2, the cost of production
per tonne of cane is lower in ratoons, even with slightly lower yields. Ratoon
productivity improvement, therefore, should help improve over-all profits greatly.
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USE OF INTERCROPS TO IMPROVE PROFITABILITY
Sugarcane cultivation practice followed offers considerable scope to grow
intercrops to improve profitability of the sugarcane production systems. However,
considerable care is required for selecting suitable intercrops and their varieties, and,
management of the intercrop as well as the sugarcane in the system. Some important
considerations should be to choose high value crops with assured market, which has no
deleterious effect on sugarcane or raise the crop in such a way that it does not affect the
sugarcane. However, intercropping may need additional labour as well as inputs. This
needs careful assessment of the availability.
CROP ROTATION TO IMPROVE THE PRODUCTIVITY OF THE SYSTEMS
In sugarcane production systems, avoiding monocropping is important from the
long term productivity point of view. Crop rotations involving legumes or green manure
crops, and also high value cereal crops will be helpful to have a profitable sugarcane
based cropping sequence.
COST REDUCTION-PROFITABILITY CONCEPT
Profit is the return received on a business undertaking after all operating expenses
have been met. It is also the increase in the networth of a business enterprise in a given
accounting period. We can apply the same analogy to the sugarcane production systems.
Profitability improves and sustains the sugarcane production system. To improve
profitability as already dealt with, other farm enterprises, cropping systems (such as
intercropping) particularly centered around sugarcane can be considered. Farmers
therefore, can consider sugarcane seed production, polybag seedling raising, trash
composting, vermi composting, growing cane for other purposes such as jaggery,
chewing, juice etc., of course, after meeting the commitment of the sugar factories.
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SENSITIVITY ANALYSIS
A major requirement for efficient cost reduction is establishing the area to be
attacked. Since cost reduction is not free of cost, it is essential that savings realized
exceed the cost reduction costs sufficiently to justify its application. Sensitivity analysis
is the technique that measures the expected values in a decision model that will be
affected by changes in the application of any new technology. Thus, before adopting or
introducing a new technology with the objective of cost reduction, or to improve
profitability, the exercise must be made. This however is not the activity of the farmers.
This should be the business of the cane departments or other extension agencies that are
going to introduce the technology.
In a sugarcane production system, for example, if one wants to introduce a new
variety as a means to improve productivity for overall cost reduction, such analysis would
convince the management to justify the costs because, introduction of new variety would
involve considerable cost on seed production and promotional efforts. Same way, this
applies to any other new technology such as use of herbicides, biofertilizers, introduction
of a new machine to save labour etc.
COST ANALYSIS AND CONTROL
Cost analysis is a necessary activity before any cost reduction programme can be
initiated. The same approach is used in the treatment of cost control. The basic control
process involves a) Establishing standards; b) Measuring performance against these
standards and c) Correcting deviations from the standards.
For analysis of cost, it has to be classified. All costs can be classified on the basis
of how they are affected by changes in volume of the item being costed. Fixed costs
remain constant, regardless of the volume. Usually variable costs change. Analyses such
as capital expenditure analysis, return on investment analysis (on labour, fertilizer),
break-even analysis, incremental analysis are some of the analyses to be done for cost
reduction. Since it is not sufficient for profitability to merely cut costs, it is also
important to control costs upon completion of the reduction programme in order to
maintain profitability. Measures such as budgeting (partial or complete, and inventory
cost control, would be effectively used for cost control. To illustrate this in simple term,
84
supposing we introduce biofertilizer as a means of reducing the cost of fertilizers, then
ensuring availability of adequate quantities of bio-fertilizer at appropriate time and right
quality is essential. Otherwise, this exercise will be a futile one, so also, any other
technology. Say in case of a new variety, on continuing basis, there should be provision
to get the quality seeds.
CONCLUSION
Sugarcane production systems are becoming costlier. There is urgent need to
effect cost reduction for the benefit of both the cane farmers and factories by appropriate
cost reduction strategies. The strategies should be to reduce the basic cost element costs
by appropriate low cost technologies, productivity improvement approaches by
improving input-use efficiency and by long term productivity improvement programmes.
This calls for concerted efforts by the sugar factories, extension agencies and of course
by the farmers.
REFERENCES
Sundara, B. (2000). Cost reduction strategies in sugarcane production systems.
Cooperative Sugar, 30(11&12): 1043-1046
Sundara, B.(1998). Sugarcane Cultivation. Vikas Publishing House, New Delhi, 302 p.
85
MANAGEMENT OF PROBLEM SOILS
P. RAKKIYAPPAN
Soil is a living body and is soul of infinite life. It is one of the most important
non-renewable natural resources. Soil is the vital but scarce natural asset, which provides
very complex life support system. India is "Museum of Soils" as is gifted with all kinds
of soils. The present population and future generations to come have to depend on this
natural resource. It is the prime responsibility of every citizen to maintain the soil health
and sustain the productivity by adopting suitable specific scientific soil and crop
management practices. About 10% of the cultivable land is reasonably free from known
constraints. One soil may suit to one particular crop but we have to cultivate a variety of
crops in a wide range of soils, which warrants correction. Although sugarcane needs a
well drained loamy soil with neutral soil reaction for its ideal growth, it is grown in
widely varying soil environments. Cane production is affected by low soil organic
carbon content, unfavourable soil reaction (pH), electrical conductivity (EC),
exchangeable sodium percentage (ESP) and poor physical conditions such as hard pans,
inadequate drainage, surface crusting and hardening, waterlogging etc. These soils need
reclamation and special management practices to improve their productivity.
MAINTENANCE OF SOIL ORGANIC MATTER
ROLE
Soil organic matter, being one of the soil constituents, helps in better soil structure
formation and provides the most favourable air and water regimes. It is the source of
plant nutrients including micronutrients, which are liberated in available form during
mineralisation. It increases the water holding capacity, buffer and exchange capacity and
microbial activity of the soils. Hence soil organic matter is considered as an elixir of soil
productivity. It is important to improve and maintain the soil organic matter content to
achieve higher productivity. Our soils are generally low in organic matter content due to
rapid decomposition owing to high soil temperature and improper cultural practices.
86
SOURCES
Soil organic matter content can be improved and maintained by liberal application
of green manure, green leaf manure, farm yard manure, compost and bulky organic crop
residues. Pressmud obtained from sugar factory, sugarcane trash, straw, husk, coir pith
waste, vegetable or fruit peelings etc. can be properly collected, composted and used as
manure.
ENRICHMENT OF PRESSMUD
Large quantity of pressmud (3% of cane crushed) is available at every sugar
factory. Fresh pressmud has wide C: N ratio and evolves a lot of heat during
decomposition. Hence it should be applied only after proper decomposition. The
technique developed at Sugarcane Breeding Institute for rapid decomposition and
enrichment of pressmud using microbes is described below:
Fresh pressmud can be spread to 1 metre width and 3 metre length (depending
upon the quantity) to about 15 cm thickness. Then microbial culture - Pleurotus or
Trichoderma viride (1 kg/tonne of pressmud), urea (5 kg/tonne of pressmud) and
cowdung as a starter (50 kg/tonne of pressmud) can be sprinkled over this layer by
mixing them in water. Then another layer of pressmud to a thickness of 30 cm can be
added over the first layer. Again microbial culture, urea and cowdung can be sprinkled.
This process is repeated until we reach a height of about one metre. The top layer can be
covered with soil. Water is sprinkled to moisten it to 50% water holding capacity. This
moisture level is to be maintained throughout. Decomposition will be over within 6 to 8
weeks. Rock phosphate, ferrous sulphate, zinc sulphate etc. can also be added to improve
the nutrient contents. The pressmud thus composted is dark in colour with narrow C:N
ratio (about 10:1). The well decomposed pressmud can also be used as a source of
inoculum @ 1:5 ratio (Decomposed : Fresh pressmud).
SUGARCANE TRASH COMPOSTING
A huge quantity of sugarcane trash is being burnt every year. About 10-15 tonnes
of trash is being produced from one hectare of sugarcane field yielding 100 tonnes of
cane. Instead of burning the trash, it can be properly collected, composted and used as
organic manure. Trash contains about 0.35% N, 0.13% P205, 0.65% K2O, 0.27% CaO
and also appreciable quantity of micronutrients with wider C:N ratio (60:1). The
87
following method can be adopted for composting the sugarcane trash and using the same
as an useful manure.
The collected sugarcane trash can be spread in the corner of the field or in a
suitable place to a width of 3 metre and a breadth of 7 metre to a height of 15 cm (about
100 kg of trash). Over this, about 100 kg of pressmud can be spread. Then 10 kg of
mixture of rock phosphate, gypsum and urea (5:4:1) can be spread over this along with 10
kg of well decomposed FYM or compost and 10 kg of cowdung as a starter. Then the
entire layer could be moistened. This process can be repeated till the heap reaches 1.5
metre height. Then, the top layer is covered with the mixture of soil and pressmud to a
height of 5 cm. The moist condition at 50% water holding capacity should be maintained
throughout by sprinkling water at 10 days interval. After three months, this should be
raked, mixed thoroughly by spade and again heaped. At the end of 5th month, the trash
becomes a good compost with narrow C : N ratio (10:1), N = 1.80%, P205 = 0.51 %,
K2O = 0.20%, CaO = 1.20% and appreciable quantity of micronutrients.
MANAGEMENT OF SALINE/SODIC SOILS
CAUSES
The major soil problem in India is salinity/sodicity, affecting 7.25 million
hectares in our country. Salt accumulation in soil is primarily due to weathering of parent
materials in arid and semiarid regions where evaporation is greater than precipitation i.e.
there is not enough rainfall to leach the salts. Use of poor quality irrigation water, rise in
ground water table, impeded drainage, indiscriminate land use pattern and construction of
reservoirs and inundation of sea water also lead to salt accumulation.
EFFECTS
Salinity/sodicity causes reduction and delay in germination in sugarcane setts. It
causes burning of tips of young leaves and edges of older leaves. In extreme cases, the
spindle dries up exhibiting a burnt appearance. It retards stem elongation, root
development and tillering resulting in poor yield and juice quality. The canes harvested
from salted soils are withered and pithy. Normally sugarcane crop stand is poor in salt
affected soils with slick or barren spots in the field. EC of 4 mmhos/cm and ESP of 15
are considered as threshold levels.
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RECLAMATION
For better cane production, the salted soils need reclamation in saline soils, the
reclamation process involves leaching of excess soluble salts. It is also important to
avoid further accumulation of salts. For reclamation of saline soils, the field is levelled
first and divided into small plots of about 1000 sq.metres by providing bunds. Drainage
channels of 75 cm depth are provided all-around the field. The field is irrigated
copiously with good quality water and stagnated for two to three days so that the salts in
the soils get dissolved. Then the salts are removed by draining the water through
drainage channels (vertical drainage) so that the salts are removed from profile atleast to
a depth of 75 cm. This leaching process has to be repeated till the soil is free of harmful
salts. Surface drainage has to be avoided. Leaching and drainage can be improved by
applying huge quantities of organic manures and mechanical treatments like deep
ploughing, sub-soiling, sanding and profile inversion.
Reclamation of saline/sodic soil involves the addition of amendments to replace
excess of sodium present in exchange complex with calcium ion. Then the excess
soluble salts and sodium salts formed are to be removed as in the case of saline soils.
Regarding the sodic soils, the physical condition is to be improved by addition of
large amount of organic matter in addition to chemical amendments to replace sodium by
calcium in the exchange complex and to remove carbonate and bicarbonate with sulphate.
Generally gypsum, phosphogypsum, pressmud, sulphur and pyrites are recommended as
amendments. Gypsum is the most effective and cheap amendment. The recommended
quantity of powdered gypsum (2.5 to 12.5 t/ha depending upon soil pH, ESP and soil
buffering capacity) is applied to the soil by broadcasting, irrigated with good quality
water and ploughed thoroughly so that the reaction takes place effectively. The reaction
of gypsum in sodic soil is as follows:
Clay Na+ + Ca++SO4-- ……………….. Clay Ca++ + Na2SO4
Na+
When gypsum is applied to the sodic soil, it ionises into calcium and sulphate
ions. Sodium ion exchange site is replaced by calcium. The sulphate and replaced
sodium ions form sodium sulphate, which is highly soluble in water and leached easily.
The process recommended for leaching is the same as that advocated for saline soils.
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Pressmud, a sugar industry by-product, can be profitably used in reclamation of
sodic soils. It contains considerable amount of N (1.20%), P205 (3.83%), K20 (1.46%)
and CaO (11.10%) and improves soil fertility status also. It also saves 25% inorganic
fertilizers. Application of 12.5 to 20.0 tonnes of pressmud per hectare may be useful to
reclaim alkali soils. Pressmud can be enriched by using Pleurotus and Trichoderma
along with urea (5 kg/t) and cowdung (50 kg/t) as starter. After reclamation, the
following points are to be considered while using alkaline soils for cultivation.
1. Level the land and maintain it
2. Apply huge quantity of organic manures
3. Use 25 per cent more N than recommended
4. Apply 25 kg FeSO4 and 12.5 kg ZnSO4 per hectare
5. Irrigate with less quantity of water at frequent intervals.
6. Improve drainage facilities
7. Grow resistant sugarcane varieties (Co 453, Co 853,Co 740, Co 6304,
Co 85002 and Co 85007)
8. Use physiologically acidic fertilizers
1. Mulching can be practised. Enriched pressmud, coir pith, groundnut
shell and safflower hull may also be applied to improve soil physical
conditions
10. Monitor soil pH, EC and ESP and avoid salt accumulation
MANAGEMENT OF ACID SOILS
Sugarcane is also cultivated in acid soil in some areas of Kerala, Karnataka and
Goa. Acid soils are characterized by low pH (less than 6.5) which leads to increased
solubility of aluminium, iron and manganese often to levels that are toxic to the plants.
Shoot elongation as well as tillering of cane is adversely affected. Application of lime
(2.5 to 7.5 t/ha) is recommended to raise the pH to neutrality. The quantity of lime
recommended depends on the pH, CEC and buffering capacity of the soil. The common
liming materials are burnt lime, pulverised limestone and dolomite. The caustic nature of
the burnt lime causes handling difficulties and is also costly. However pulverised
limestone and dolomite are cheaper and safe for handling. Liming materials are to be
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applied before ploughing. Red and laterite soils benefit largely from regular and
adequate liming. Among the phosphatic fertilizers, bone meal and rock phosphate are
well suited for acid soils.
SOIL PHYSICAL PROBLEMS AND THEIR MANAGEMENT
In heavy textured black soils, compaction and presence of hard pans in the root
zone restrict the root growth resulting in poor nutrient and water uptake and consequently
poor yield. Effective root system of cane crop normally spreads to 45 cm both
horizontally and vertically. Deep ploughing or chiselling to break the hard pan will
facilitate deeper and better root growth, resulting in higher nutrient and water uptake
leading to maximum production. Besides, all the tillage operations must be carried out at
optimum moisture level so that soil structure is not destroyed and soil compaction is
prevented. Application of heavy dose of organic manure will also avoid compaction and
improve the structure. Compaction in sodic soils can be avoided by ameliorating with
gypsum. Sand application over years will also improve the texture.
In most of the areas, cane is cultivated after paddy. Due to puddling for paddy
crop, soil structure is spoiled and impervious layer is formed. As a result, sugarcane crop
grown after paddy gives poor yield. Deep ploughing after paddy will help to overcome
such problems and it will benefit the main crop as well as the ratoon. In black soils,
cracks occur due to drying and as a result the roots are cut off. When the field is irrigated
again, lodging of cane occurs. This can be avoided by irrigating at optimum soil
moisture and trash mulching. Application of huge quantity of organic manures and
organic wastes like groundnut shell, safflower hull, tamarind seed, paddy husk, coir pith
and pressmud may also help in this regard. Cane crop in these soils suffers due to poor
drainage. This can be improved by providing open drains of 75 cm depth for every 15 to
20 rows of cane. Mole drains and underground tile drains are also effective.
Shallow rooted varieties like CoC 671 and Co 6907 are affected more by soil
compaction, hard pans and cultivation of cane after paddy. The root system of such
varieties could be improved by high earthing up.
In the case of open textured red soils, cane production is affected by surface
crusting and hardening which restrict sprouting and root growth. This occurs in soils
having 60-80 per cent sand with predominance of fine sand. Light and frequent
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irrigations and incorporation of paddy husk or groundnut shell at the rate of two tonnes
per hectare in surface soil will overcome this adverse effect. Besides, moisture retention
is also improved. In the light textured sandy soils, production can be improved by
addition of organic matter, clay and silt and by soil compaction. This will improve the
soil physical environment, moisture retention and water and fertilizer use efficiency of
cane crop.
MANAGEMENT OF WATERLOGGED SOILS
Sugarcane is somewhat tolerant to excess moisture/waterlogging. But the stage of
the crop at the time of excess moisture and the duration of the excess moisture situation
decide the extent of tolerance. If it occurs during germination phase, it is highly
detrimental. Unless the excess moisture is removed immediately, there may be failure of
germination that might lead to total loss of the crop. In other stages, the sugarcane crop
is able to tolerate excess moisture conditions for about a week. But when it exceeds this
limit, damage begins to occur. The damage or loss in yield is directly proportional to the
duration of the excess moisture situation.
During tillering phase, excess moisture causes death of tillers. In the grand
growth phase, it affects the cane formation and cane elongation. At maturity phase, it
induces early ripening but deteriorates the juice quality.
Excess moisture causes root decay and prevents root development because of the
anaerobic conditions. This reduces the uptake of water and nutrients from the soil and
causes physiological drought, which leads to the crop loss. Hence, management of the
excess moisture situation is as important as the management of the drought situation. To
achieve this, the water coming from outside the field has to be checked. If excess
moisture situation is anticipated, a network of drainage trenches are to be made in every
field prior to planting and they should be maintained properly throughout the crop period.
Through these drainage trenches, excess water must be removed and let into the natural
drains. Water from the field drains may also be collected in a small well like structure in
a corner of the field and can be pumped into the natural drains.
Adoption of certain cultural practices like early planting, use of higher seed rate,
use of polybag single bud settlings and Partha method of planting (planting setts in an
erect but slanting position at 60o with one bud inside the soil) will be helpful under early
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waterlogging situations. Varieties Co 775, Co 785, Co 975, Co 997, Co 8371, Co 951,
Co 6604, Co 454, Co 1148, Co 740, CoSi 86071, BO 91, Co 1158, Co 62175, Co 8231,
Co 8232, WL 8422, Co 87267 and Co 87270 are tolerant to waterlogging.
NUTRIENT DEFICIENT SOILS
Indian soils are in general poor in nitrogen and well supplied with phosphorus and
potassium. Application of N P K fertilizers based on soil test results will help in
improving sugarcane productivity.
Iron chlorosis is common mainly due to high lime content in soil. This can be
corrected by repeated foliar spray of ferrous sulphate (1.0 to 2.0%) with 0.1% citric acid
at weekly intervals till the chlorosis vanishes. In normal soils, soil application of ferrous
sulphate (@ 50 kg/ha) will alleviate this malady. Application of 150 kg of ferrous
sulphate along with organics is recommended for calcareous soils. Varieties Co 86032
and Co 8021 being tolerant to iron deficiency are recommended for cultivation in iron
deficient calcareous soils. Zinc deficiency is also noticed in some soils. This can be
corrected by foliar spray (0.5%) coupled with soil application (25 kg/ha) of zinc sulphate.
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BIOFERTILIZERS FOR SUGARCANE
K. HARI
INTRODUCTION
Integrated nutrient management which aims at the judicious use of inorganic,
organic and microbial sources of fertilizers to sustain optimum crop yields and to
improve or atleast maintain the physical, chemical and biological properties of the soils is
the need of the hour. Biofertilizers are preparations containing live or latent cells of
efficient strains of nitrogen fixing, phosphate solubilizing or cellulolytic microorganisms
used for application to seed, soil or composting areas with the objective of increasing the
population of specific microorganism and accelerate certain microbial process to improve
the availability of nutrients (Subbarao, 1988). Microbial inoculants, which are cheaper
and eco-friendly, play a very significant role in improving soil fertility.
Fertilizer demand for sugarcane is high and this can be supplemented by
biofertilizers along with chemical and organic fertilizers. Sugarcane supports growth and
colonization of many beneficial bacteria. Among the various microorganisms, the
nitrogen fixing and the phosphate solubilizing bacteria are given importance as they can
meet part of the fertilizer need.
BIOFERTILIZERS FOR NITROGEN FIXATION
The N2 fixing bacteria generally found associated with sugarcane crop are
Azospirillum, Acetobacter, Azotobacter, Beijerinkia, Derxia, Pseudomonas, Bacillus,
Enterobacter, Klebsiella and Herbaspirillum. Although sugarcane crop encourages the
growth and proliferation of these bacteria studies indicated that Azotobacter, Azospirillum
and Acetobacter as efficient nitrogen fixing biofertilizers.
Azotobacter is an aerobic and free living bacteria found in high numbers in the
rhizosphere zone of plants. They fix nitrogen and produce growth promoting substances
in the rhizosphere zone. Azotobacter uses soil organic matter and plant root exudates for
fixing atmospheric nitrogen and produce growth promoting substances and
polysaccharides that help in improving the physical characteristics of soil. They are
relatively more effective in the soils rich in organic matter.
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Azospirillum is an efficient nitrogen fixing bacteria capable of colonizing the
roots of plants. The low oxygen availability conditions prevailing in rhizosphere soil and
root surface is an ideal environment for the growth and nitrogen fixation of Azospirillum.
They also produce growth promoting substances and polysaccharides.
Presence of Acetobacter diazotrophicus in sugar rich crops like sugarcane, sweet
sorghum, ragi, coffee and sweet potato has been reported (Boddey and Dobereiner,
1995). This bacterium can fix high quantities of atmospheric nitrogen comparable with
that of the Rhizobium. This bacterium is an endophyte, which can colonize the root
surface and also the inner parts of the sugarcane plant.
EFFECT OF BIOLOGICAL NITROGEN FIXING (BNF) BIOFERTILIZERS ON
SUGARCANE
Studies were conducted at Sugarcane Breeding Institute, Coimbatore to study the
response of sugarcane varieties with different inorganic fertilizer nitrogen doses, along
with the different biofertilizer cultures viz., Azotobacter, Azospirillum and Acetobacter.
The overall results showed that Azospirillum improved 12.2% cane yield followed by
Acetobacter (5.2%) and Azotobacter (3.8%) over uninoculated control (Fig. 1).
Fig. 1 Effect of different biofertilizers on the cane yield of sugarcane
Varietal differences in response to biofertilizer application have been recorded
(Table 1). Overall, the results indicated that the varieties tested showed significant cane
yield improvement due to Azospirillum inoculation compared to control, while the
response due to Azotobacter and Acetobacter differed among the varieties. Maximum of
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17.2 % yield improvement was observed in Co 8021 due to Azospirillum inoculation
compared to uninoculated control (Hari and Srinivasan, 1996).
Table 1: Effect of different biofertilizers on the cane yield of different varieties
Sl. No.
Varieties Cane Yield t ha-1
Azotobacter Azospirillum Acetobacter Uninoculated Mean
1. Co 8014 108.9 109.5 107.7 99.3 106.4
2. Co 8122 88.8 112.3 93.93 90.1 96.3
3. Co 8021 104.4 119.2 110.9 101.7 109.1
4. Co 6304 121.2 123.1 118.4 116.4 119.1
5. CoC 85061 123.5 127.3 123.9 119.7 123.6
Mean 109.4 118.3 110.9 105.4
CD at 5% Biofertilizers: 2.88 Variety x Biofertilizers: 6.5
EFFECT OF N DOSES ON BIOFERTILIZER RESPONSE
The treatments with different fertilizer N doses along with Azospirillum and
Acetobacter inoculum showed significantly higher cane yield with the nitrogen dose 200
kg N ha-1 (Fig.2) than with 300 kg N ha-1(Hari and Srinivasan, 1996 ).
Fig. 2 Effect of applied N with biofertilizers on cane yield of sugarcane
The cane yield data was processed for quadratic regression analysis to find the
physical optimum dose of applied fertilizer required for different sugarcane varieties with
and without Azospirillum (Hari,1995). Physical optimum dose of fertilizer is the dose of
fertilizer required to get maximum cane yield. The results of the analysis clearly
96
indicated that Azospirillum inoculation considerably reduces the requirement of fertilizer
nitrogen to get the maximum yield benefit (Table2).
Table 2: Physical optimum dose of inorganic N required for different varieties with Azospirillum
Sl. No.
Varieties Physical optimum N kg ha-1
With Azospirillum Without Azospirillum1. Co 8122 290 3522. CoC 671 311 3603. CoSi 86071 251 3034. Co 8021 246 2505. Co 7634 248 2786. Co 740 232 2657. Co 7204 265 2968. Co 775 268 2859. Co 7201 270 31810. Co 62175 255 293
Note: Varieties Co 8133, Co 6304, Co 8014 & CoC 85061 responded linearly even
beyond 300 kg N ha-1
Detailed trials conducted in the farmer's holdings of various sugar factories in
Tamil Nadu also indicated that inoculation of Azospirillum resulted in considerable
improvement in the cane yield with 75% of the recommended inorganic N fertilizer dose
(119.9 t ha-1) compared to recommended inorganic N fertilizer dose (110.6 t ha-1).
Response of sugarcane as indicated by cane yield was significant due to Azospirillum
inoculation in different soil types viz., alluvial, clayey and sandy soils (Srinivasan and
Mohan Naidu,1987).
BIOFERTILIZER FOR PHOSPHATE SOLUBILIZATION
Indian soils are generally low to medium in available phosphorus. The fertilizer
phosphorus applied to crops is generally converted to relatively unavailable forms and
only 10 to 15 per cent alone are made available to the crops. Many soil bacteria and
fungi bring this insoluble inorganic phosphate into soluble forms by producing organic
acids. The most efficient phosphate solubilizing bacteria are Bacillus megaterium, B.
polymyxa and Pseudomonas striata. Inoculation of these cultures have improved the
yield of many crops and also improved the P uptake and P availability. In general the
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bacterium Bacillus megaterium is recommended as phosphate solubilizing biofertilizer
(Gaur, 1990).
Field experiments were conducted at Sugarcane Breeding Institute to evaluate the
response of sugarcane varieties to the application of phosphobacteria (PSB) along with
combinations of super phosphate and rock phosphate keeping the total phosphorus dose
constant. About 12.7 per cent higher cane yield was recorded in Phosphobacteria applied
plots over those not applied with phosphobacteria. Substitution of super phosphate with
rock phosphate to the extent of 50 per cent is possible when used along with
phosphobacteria (Fig. 3).
Fig. 3 Effect of application of phosphobacteria of cane yield
Due to phosphobacterial application, improvement of soil available P status and
juice quality was noticed. On the ratoon crop, a higher stalk population was recorded in
the phosphobacteria applied plots over uninoculated plots. The stalk population was
highest (89,599/ha) in the superphosphate (100% P dose) + phosphobacteria applied
followed by the plots in which superphosphate was substituted to the extent 50% with
rock phosphate and supplied with phosphobacteria (87,963/ha). In general, better growth
has been noticed in plots supplied with rock phosphate along with phosphobacteria.
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BIOFERTILIZER PRODUCTION
Generally, efficient microorganisms are used as biofertilizers. For this purpose
biofertilizer strains are isolated from the different sugarcane growing areas. After testing
under lab and field conditions, the efficient cultures are identified as biofertilizer. The
microorganisms are aseptically grown in liquid media containing the nutrients required
for the microorganism to grow. Under suitable temperature and aeration, the
microorganisms grow to sufficient numbers in about a week. This fully grown liquid
culture contain about 1 x 109 cfu ml-1. This liquid culture is then mixed thoroughly with
stabilized carrier materials like peat soil or lignite powder. This biofertilizer material
should contain about 25 to 35 percent moisture, as this moisture is very essential for the
survival of the microorganisms (Motsara et al., 1995).
OVERALL BENEFITS
Cane yield improvement
Fertilizer saving
Plant growth promotion
Improved use of applied fertilizer
Improved water uptake, mineral uptake and health by the crop
Improved soil fertility
DOSAGE AND METHOD OF APPLICATION
Lignite based cultures are available for inoculation. The recommended dose for
sugarcane crop is 5.0 kg Azospirillum (or Acetobacter) plus 5.0 kg Phosphobacteria per
acre. The biofertilizer should have a minimum bacterial load of about 107 colony forming
units (cfu) per gram of biofertilizer material. The biofertilizer can be applied in two
methods viz., sett soaking and soil application. Studies conducted at Sugarcane Breeding
Institute, Coimbatore revealed that application of Azospirillum either by sett soaking for 2
h or soil application did not show significant yield difference (Rajaram and Srinivasan,
1987). Soil application method is generally recommended for sugarcane when
Azospirillum is applied. For Acetobacter, since it is an endophytic bacterium, in addition
to soil application, sett soaking also can be followed.
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For sett soaking, 1.0 kg of the biofertilizer is mixed well with 100 l of water and
the setts are soaked for 20 to 30 min and planted. For soil application, the biofertilizer is
applied in two doses, application of half of the dose at 30 days after planting and a second
dose after 60 days. For application, the biofertilizer is mixed thoroughly with 500 kg of
powdered farmyard manure/compost/pressmud and uniformly applied near the base of
the crop. For better results, application of both Azospirillum and phosphobacteria is
recommended. Biofertilizer application should necessarily be followed by slight earthing
up to cover the biofertilizer with soil, followed by irrigation to ensure optimum moisture
conditions for proper bacterial growth.
GENERAL PRECAUTIONS
The biofertilizers can only be complimentary or supplementary to chemical
fertilizers to meet the nutrition demand of the crop. They cannot replace chemical
fertilizers completely. It can only supplement 20 to 25 per cent of the nitrogen
requirement of the crop and improves the scope for using the cheap low grade P sources.
While applying this biofertilizer, the soil should have sufficient moisture to obtain best
results. Biofertilizer should not be mixed directly with insecticides, fungicides,
herbicides or chemical fertilizers, as these chemicals at higher concentration will kill
these biofertilizer cultures. The packets can be stored in room temperature away from
sunlight for about six months to one year period.
REFERENCES
Boddey,R.M. and Dobreiner,J.1995. Nitrogen fixation associated with grasses and
cereals: Recent progress and perspectives for the future. Fert. Res.,42,241-150.
Gaur, A.C. 1990. Phosphate solubilizing microorganisms as biofertilizer. Omega
Scientific Publishers, New Delhi. pp. 176.
Hari, 1995. Biofertilizers in sugarcane. Lead paper presented in 10th sugarcane R&D
workers meeting of South Karnataka, Shimoga, 2 - 3, June, 1995.
Hari, K and Srinivasan, T,R. 1996 Effect of biofertilizers under different nitrogen levels
on sugarcane varieties Paper presented in the X Southern regional meeting on
microbial inoculants, AVVM Sri Pushpam college, Poondi, Thanjavur, Tamil Nadu,
India, on 10&11 December 1996.
100
Motsara, M.R., Bhattacharyya, P and Beena Srivastava. 1995. Biofertilizer Technology,
marketting and usage. Fertilizer Development and Consultation Organization, New
Delhi, pp 184.
Rajaram,V. and Srinivasan,T.R. 1987. Methods of application of biofertilizers in relation
to sugarcane varieties. Proc. 50thAnnual Convention of STAI, Kanpur, India.
Srinivasan, T.R. and Mohan Naidu, K. 1987. Response of sugarcane varieties to
biofertilizers under different soil conditions. Sugarcane, 3, 5-10.
Subbarao, N.S. 1988. Biofertilizers in agriculture. Oxford & IBH, New Delhi. pp. 375.
Subbarao, N.S. 1986. Soil microorganisms and plant growth. Oxford & IBH, New Delhi.
pp.311.
101
POST-HARVEST DETERIORATION OF CANEAND SUGAR LOSSES
S. ASOKAN
Sugarcane plant, once severed from the ground can do little to manufacture new
sugar, on the contrary its capacity to lose stored sucrose increases tremendously due to
intrinsic and extrinsic factors. Thus a well-ripened harvested crop, may lose its sugar
within a few days after harvest, which tends to increase further due to high ambient
temperature, pre-harvest burning, harvest and transportation injuries and microbial
infestation. These losses tend to increase during processing, especially in those units
where hygienic conditions are rather unsatisfactory. The post-harvest sugar loss is one of
the most vexing problems of sugar industry and has attracted wide spread attention in the
recent years.
In sugarcane growing countries any of the following constraints seem to operate
at farmers and factory level. These may considerably delay the milling of harvested crop
and affects the quality of raw material and consequently sugar recovery:
1. Absence of a proper varietal balance and scientific harvesting schedule
based on cane maturity
2. Extension of milling period during summer months when ambient
temperature is high (> 40oC)
3. Practice of harvesting sugarcane crop 3 to 6 days in advance before its
supply to mills, in some areas of sub-tropical India, this delay is around
7-10 days
4. Limited crushing capacity of the mills resulting into staling of cane at
mill yard/cane centres (an intermediary agency between farmers and mill
which manages supply of cane)
5. Inordinate delay in transport of harvested cane from farmer's field/cane
centres to the mills and lack of an efficient communication net-work
6. Complete absence of cane laundering/cleaning system, practice of
uprooting, burning and detopping of cane in certain areas
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7. Week-end shut down and other unforeseen circumstances, such as labour
scarcity and power interruption
8. Absence or lack of understanding regarding cane and mill sanitation
program and use of proper biocides during milling
9. Mechanical harvesting of sugarcane (burnt crop) without proper and
timely supply arrangements
CAUSES OF POST-HARVEST DETERIORATION
The following causes are often attributed to post-harvest cane staling at the
farmer's field/mill yard and in the milling tandem:
(a) Nature of varieties grown in the area (rind hardness, wax content) and
their inversion behaviour
(b) Moisture and original condition of cane, maturity status of the crop
(c) Pre-harvest practices such as burning and severity of fire, detopping etc.
(d) Atmospheric conditions, viz. temperature, humidity and rainfall
(e) Methods of harvesting viz. hand cut or mechanically harvested
(f) Size of billets (short/long green, short/long burnt)
(g) Storage methods (open storage or in piles, size of the piles) and duration
(h) Time lag between harvesting to milling
(i) Sanitary conditions inside the mill as well as efficiency of processing
(a) Crop history, viz. incidence of pests and diseases; factors affecting
growth and quality of crop viz. saline/alkaline/drought/waterlogged
conditions
(k) Physical condition of cane i.e. number of bruises, presence of mud etc.
According to Foster and Ivin (1981), pre-harvest burning of sugarcane practiced
in some western cane growing countries viz. Australia, Iran, Jamaica causes major
physico-biochemical changes in cane plants. These metabolic changes along with
microbial infestation and other factors such as thermal destruction of sucrose, high
inversion rate, water loss and loss of sugar by exudation on the cane surface are
additional reasons for lowering CCS value of burned crop.
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CANE TRANSPORT AND STORAGE SYSTEM
The cane transport system ranges from man, bullock carts, camel carts, canals to
highly mechanized road and rail cars and is a major factor governing quality of harvested
cane. The time factor during transport, storage conditions, degree of damage from
loading equipment and size and shape of transport containers are important factors in
governing cane quality.
FACTORS AFFECTING CANE DETERIORATION CANE VARIETY
Sugarcane varieties play a crucial role in sugar recovery, depending upon the
climate and management practices followed. A very big difference in susceptibility to
post-harvest deterioration has been noticed which is important in countries where there is
a long delay prior to crushing such as India, Sri Lanka, Bangladesh, Pakistan and Nepal.
Sugarcane varieties, in addition to their inversion behaviour may also have an effect on
its susceptibility to Leuconostoc infection.
The current situation is that almost all cane varieties are prone to post-harvest
deterioration but the rate of moisture loss may vary due to their physical, chemical and
bio-chemical constitution as well as prevailing environmental conditions.
ENVIRONMENTAL FACTORS
There are ample evidences to show that weather is of prime importance in
determining the rate of deterioration. Higher the temperature and humidity, and wetter
the weather, the greater is the deterioration. Deleterious effects of high temperature
(around 40oC) and low atmospheric humidity (25-35%) on juice quality have been
reported by many workers. Numerous early workers surmised temperature-moisture
relationship to deterioration of cane and there was general view that cane stored in the
shade or covered with trash are less prone to deterioration than if stored in open place.
In Hawaii, Wold (1946) found that deterioration of cane was closely related to
moisture and original condition of cane than to storage methods i.e. piles vs. open
storage. His observations are sound, clean, dry cane deteriorates much slower than cane
which is damaged, dirty and wet, as, of course, we would expect to be the case.
The activity of internodal invertase(s) as well as microbial population increased
manifold with the concomitant increase in the level of reducing sugars, which has a
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detrimental effect on sucrose recovery. Higher night time temperature triggers off
dextran production in stored cane. These observations show that environment play a
major role in quality decline and weight loss after harvest, however, variety factor also
influences deterioration process, but to a certain extent.
CROP MATURITY
The fully mature cane will not deteriorate as rapidly as either immature or over
mature cane. This deterioration is relatively faster in hot weather. Foster (1969) and
Alexander (1973) emphasized that maturity was a major factor in the rate of inversion in
stored cane. As maturation level increased the extent of deterioration slackened.
DETERIORATION OF GREEN AND BURNED CANE
Burned and unburned cane behave differently during storage. Much controversy
still exists on the subject, with the literature favouring green cane as being less
susceptible to post-harvest deterioration as compared to the burned cane. Young (1963)
performed elaborate experiments with burned harvested and standing cane and noticed
that sugar losses in cut cane were more as compared to burned standing cane. Delaying
the harvesting of burned standing cane for more than 24 hours resulted in a marked loss
in the yield of sugar. Foster and Ivin (1981) reported that severe fires could lead to mass
loss of about 6 per cent one day after burning. It has been noticed that in case of hand cut
full cane the sugar losses within 24 hr are negligible during early milling, but increased
substantially during late-milling (Solomon et al., 1997).
MECHANICAL HARVESTING
The introduction of mechanized harvesting and subsequent chopping of green
cane has also resulted in serious problem, especially dextran formation. The mechanical
harvesting with consequent delay in delivery of cane to sugar factory continue to be one
of the major problems affecting factory efficiency and sugar quality to a great extent.
The post-harvest losses in crop, harvested by chopper harvester in Queensland (Australia)
represented 6 to 11 per cent of the original CCS present as compared to a loss of 1 to 2
per cent in the stored whole cane.
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NATURE AND MAGNITUDE OF POST-HARVEST LOSSES
The time lag after harvest and the external temperature are most important factors
which determines the rate of sucrose loss through inversion, dextran, formation
(biochemical and microbiological) and respiration.
In India, cane is harvested manually which is mostly unburned full green cane.
There is no planned burning of crop, however, in south Gujarat, irrespective of measures
taken by factory, burning of cane is a routine practice and burnt cane upto 80 per cent is
observed, especially near the end of crushing season. In some parts of north India, burnt
cane is supplied at the end of crushing season, especially when cane is in plenty. Good
harvesting practices are followed in western Maharashtra, north Karnataka and parts of
south Gujarat, where cane plantation is planned and harvesting is entirely carried out by
the factory. Other states depend on farmers for cane supplies, leaving maximum
possibilities for irregularities. It has been observed that appreciable amount of sugar is
lost during the time lag between harvesting to milling, even in well managed mills. In
some cases sugar losses are as high as 25 kg per MT cane in summer in Uttar Pradesh,
the losses are higher in certain areas of Tamil Nadu an Andhra Pradesh where
temperature is high. On an average, Indian Sugar mills lose about 10 to 15 kg of sugar
per tonne of cane ground. These losses are further escalated when crushing is extended
till May/June or even later. The enormous amount of sugar lost during post-harvest
operations point out the feasibility of increasing sugar production in field level if sugar is
not proportionately recovered in the factory.
Magnitude of cane deterioration further increases if the cane supplies are from
problem soils such as saline, alkaline, waterlogged, burnt field, fields receiving excessive
application of nitrogenous fertilizer, crop damaged by frostor affected by pests and
diseases. Freeze also causes considerable deterioration in quality and affected by variety,
disease, canopy, nutrition, soil moisture and duration of cold.
CONSEQUENCES OF CANE STALING
The phenomenon of post-harvest cane deterioration affects both growers as well
as sugar industry. As discussed earlier, loss of moisture from the harvested cane affects
the growers due to reduction in cane weight, as payment is made on weight basis in most
of the developing countries. The sugar industry loses money due to low recovery from
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the stale cane. In addition to these, many undesirable compounds are formed as a result
of bacterial growth, and chemical reactions, which create problems in sugar processing.
LOSS IN CANE WEIGHT
Cane starts to lose weight by drying out as soon as it is harvested. The percentage
loss varies widely with temperature, humidity, wind speed, variety, method of storage
etc. The loss in cane weight is more in case of chopped cane than full cane as observed
after 72 hrs of staling. Solomon (1996) observed weight loss between 7.14 to 15 per cent
under sub-tropical conditions and also found that the weight loss may be as high as 16-18
per cent after 120 hours of storage, during May and June.
LOSS IN SUGAR
Commercial Cane Sugar (CCS) is the first quality factor that is looked at while
considering the deterioration. But it is total recoverable sugar that is of paramount
importance. Based on the available literature and studies carried out in India around 10-
15% sucrose is lost after harvest of cane and its subsequent delay in processing.
ECONOMIC IMPLICATIONS OF CANE STALING
Cane starts to lose weight by drying as soon as it is harvested. Although, the per
cent loss varies widely with the variety and external conditions, farmers do not get
adequate return on the investments they have made on raising the crop. It is estimated
that under normal weather conditions, if transport of harvested cane to the factory is
delayed by 24 hours, farmer loses about Rs. 2000 (US $ 48) per day for every 100 ton of
cane supplies to the sugar mill. The revenue losses due to staling during late-crushing
may be as high as Rs. 12,000.
The studies conducted in other locations of Indian sub-tropics show that mill
(2500 TCD) crushing stale cane (72 hrs) loses about Rs. 25 to 4.0 lakh/day on account of
low sucrose recovery. These losses may further escalate depending upon the variety,
duration of storage and ambient temperatures. In addition to revenue loss, sugar mills
encounter many processing problems on account of many undesirable products formed
due to staling. In a similar study conducted at Sakthi Sugars Ltd., it was observed that
considerable fall in juice quality and sugar recovery occurs after 72 hours of staling. It is
computed that for a factory of 4000 TCD loss in cane weight was about 80 tonnes during
March for every 24 hours delay in crushing. The sugar loss is worked out to be about 75
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tonnes, which is equivalent to Rs.8.5 lakhs. In addition to these, indirect losses such as
processing, heat loss, etc. due to dextran will tend to escalate total revenue losses.
BIOCHEMICAL BASIS OF POST-HARVEST SUGAR LOSSES
The deterioration of harvested cane is primarily a biochemical process followed
by bacterial inversion through the cut ends or damaged sites of stalk. The time lag
between harvesting and milling is therefore, of crucial importance to achieve maximum
sugar recovery. The enzyme invertase(s) are most abundant in the immature tissue where
they perform important roles in growth process as well as sugar storage, but they are also
present in fully mature stalks. An abundance of immature cane rich in acid invertase may
play havoc during milling due to its high inversion rate within the crude juice.
Soon after the harvest of sugarcane, endogenous invertases get activated due to
rapid loss of moisture and lack of any internal physiological and biochemical control
mechanism. Besides invertase, Das and Prabhu (1988) reported the presence of amylase,
acid phosphatase, carboxymethyl cellulase and fructose 1,6 di phosphatase in stale cane.
These studies indicated that majority of hydrolytic enzymes get activated, especially acid
and neutral invertase(s) during staling of cane, which are responsible for major losses of
sucrose.
INVERSION CONTROL IN HARVESTED CANE: CHEMICAL METHODS
Solomon et al (1999) emphasized the need Cane Sanitation in the field, especially
in north India due to exceptionally longer harvest-to-grinding period. It was necessary to
minimize inversion and microbial infestation by sprinkling eco-friendly chemical
formulations containing a bactericide and inversion inhibitor (potassium permanganate or
sodium dithiocarbamate + sodium metasilicate) on harvested stored cane. Dipping or
spraying in solutions containing bactericidal agents viz. Actin ID, Bactrinoo-100,
Leukokil, BD Mill Sanitizer, formaldehyde, Polycide, Benzoic acid, Ifopol, Potassium
permanganate, sodium metasilicate, SucroguardTM, etc. have been tried and reviewed by
Solomon et al (1997). Coote (1984) pointed out that bactericide applied in the field, can
eliminate upto 40 per cent of the dextran in juice. Alexander (1973) reported efficacy
sodium metasilicate in controlling inversion in sugarcane juice.
MICROBIOLOGICAL ASPECTS OF CANE STALING
Micro-organisms in standing cane
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Studies conducted to assess the microflora on cane revealed the presence of
approximately 50 different microorganism on green cane, and 17 different organisms on
the burnt cane. There are genera of yeast (Saccharomyces, Torula and Pichia), of
bacteria (Pseudomonas) and of soil bacilli (Bacillus cereus) as well as Penicillium and
other fungi, Actinomyces and acid producing Streptomyces are very active. The most
important polysaccharide producing organism is Leuconostoc sp. which is responsible for
huge sugar losses in the industry, harbors under the leaf sheath, in company with
Saccharomyces, Torula and Pichia, three genera of yeast.
Micro-organisms in harvested cane
Micro-organism such as yeast, Leuconostoc and some acid producing rods are
found in the interior of cane stalk immediately after cutting. Massive infection is found
upto six inches from the cut ends after about one and half hours storage. Organisms such
as yeasts, Leuconostoc, Xanthomonas and Aerobacter the last three being producer of
mucoid material such as dextran are present at cut ends or damaged sites. Presence of
Penicillium, Actinomyces and acid producing Streptomyces was also recorded on
harvested cane.
The deterioration due to these microorganism is also known as biodeterioration
and caused by mainly Leuconostoc sp. (L. mesenteroides and L. dextranicum).
Microorganisms grow fast on the surface of burned cane, even as early as 10 min after
burning. They are predominantly rods, such as Xanthomonas, Coryne-bacterium and
Bacillus. Other organisms are found on canes standing for 24 h after burning, such as
fungi, Rhizopus and Aspergillus, and colored yeasts, Rhodotorula and Candida.
Leuconostoc is extremely common in burned cane and their numbers increase markedly
with time, after burning.
Dextran formation and sucrose losses
The dextran, which are polymers of glucose containing 60 per cent (1, 6) linkage
are produced directly from sucrose by the bacteria Leuconostoc mesenteroides or L.
dextranicum. It has been noticed that canes from a ratoon crop are more prone to dextran
formation as compared to canes from a corresponding plant crop. Dextrans are known to
create problems in processing. Therefore, staling of canes from a ratoon crop may entail
more difficulties in processing vis-à-vis losses as compared to a plant crop.
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The sucrose losses as a result of dextran formation is approximately 1.9 times the
dextran formed. Margaret Clarke (1997) and her colleagues in U.S.A. calculated the loss
of sucrose and acid produced due to dextran formation. Every 0.1 per cent of dextran
produced represents sucrose loss of 0.04 per cent.
Dextran production and sugar processing
The loss of sucrose after harvests is the greatest source of revenue loss catalyzed
by inversion and dextran formation. The detrimental dextran formation on sugar
processing and recovery are summarized below:
i. Reduction in sucrose recovery, losses are exorbitant during late-milling
ii. Formation of more reducing sugars and increased molasses purity
iii. Formation of soluble polysaccharides (starch and dextran) in milled juice
due to multiplication of Leuconostoc. sp. which leads to processing and
sanitation problems. The increased viscosity lowers heat exchange rate
and therefore, causes lower evaporator efficiency and slow crystal growth
iv. Slow crystallization, poor clarification and slow mud-settling rate.
v. Dextran impeds clarification by acting as neutral or uncharged colloids
and blocking aggregation of charged particles
vi. Excess nucleation formation of elongated crystals of sucrose which
affects its marketability (this occurs only when the dextran contains more
than 84% of 1.6 linkages)
vii. Increase in gum content leading to high viscosity of syrups, massecuites,
increase in organic acids leading to scaling problem, requiring more
heating time during evaporation
viii. Erroneous pol reading in sugar factory due to presence of dextran.
Chemical control become distorted as dextran affects the pol in varying
degree from juice through syrups to sugar
ix. The loss of time and capacity in process involving a loss of steam,
especially in the factories having power co-generation projects.
x. Dextran also creates multiple problems in sugar refinery such as pol
distortion, loss in affineation and slowing of filtration, etc. Margaret
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Clarke of Sugar Processing Research Institute, USA, pointed out problems in
products such as soft brown sugar elongated crystals, which do not pack into the
assigned containers and cloudiness in cordial and liquors
11. Dextran also poses numerous problems in sugar refinery (Chou, Wnukowski,
1980) due to its viscous nature and remains in the sugar crystal which are
morphologically abnormal. The elongated crystals prevalent in remelt sugar
create the greater increase in cost factor in the refining situation.
EFFECT OF CANE DETERIORATION ON MILLING PROCESS
The stale cane undergo further deterioration in quality during subsequent milling
operation i.e. cane preparation, juice extraction and clarification stage (Hylton, 1997).
These harvested sugarcane stalks delivered to the mills contain a large number of bacteria
which further multiplies if time lag between harvesting and milling is more. The soil
coming along with the cane is also full of bacteria. During milling process, high
population of bacteria are passed on into the extracted juice. The microbes thus entering
the juice starts their activity under favourable conditions of temperature and pH. The
conditions become worse when the disease or pest infected cane is ground in the Mills.
The activity, survival and growth of micro-organism is at its peak when the temperature
levels are between 30oC to 40oC and go in dormant condition when the temperature
exceed 95oC. The activity of microbes is considerably reduced when the juice is heated
and sent to clarifiers and remains in dormant condition in the muds and clarified juice.
the muds, pas through the filter station and the filtrates are re-circulated to the mixed
juice, where these microbes readily become active.
Diluted juice has been found to favour the growth of micro-organism and hence
the imbibition water entering the last mill speed up their multiplication. An increase in
temperature by 1oC brings about ten fold increase in the activity, maximum at 30-40 oC.
Alkaline condition (pH 8.0) greatly favours the production of dextran in juice.
MICRO-ORGANISMS IN SUGAR PROCESSING
Cane juice is a rich medium which contains about 15-18% sucrose, 0.5% reducing
sugars and adequate amounts of organic nitrogen and mineral salts for microbial growth,
its pH value ranges from 5.0 to 5.5 making it selective for acidophilic microorganisms
especially, yeasts and lactic acid bacteria. In a typical cane sugar factory, juice extracted
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from the stalks by crushing them in a series or three or five roller mills. The collected
juice is then limed to pH 8 and heated to boiling in the clarification process which
effectively kills all vegetative cells. the time interval between crushing and clarification
is approximately 15-20 minutes, but the level of microbial contamination of the juice is
usually extremely high, typical viable counts being 108-109 cells/ml juice. The microbial
population increases tremendously if there are unscheduled stoppage and no biocides are
used during milling. Nearly all microbes are eliminated during liming and sulphitation,
however, due to fluctuation in temperature as a result of frequent stoppage, certain
thermophilic bacteria have the tendency to multiply.
In sugar industry, formation of metabolic products of microbial origin have
special importance because of their effect on sucrose recovery and processing operations.
Some important metabolites of microbial origin are:
(a) Organic acids
Organic acids such as lactic acid, acetic acid and butyric acid produced by
microorganisms leads to sucrose inversion. For each gram of acid produced about 2.77 g
(L. mesenteroides) and 11.09 g (E. coli) sucrose is degraded. Juice containing excess
acid requires extra lime addition to neutralize acidity. The reaction between acids and
lime results in heavy scale formation in juice heaters, thus decreasing heating efficiency.
(b) Ethanol
Large population of yeast is invariably present in juice which not only favours the
acid but also ethanol production at the expense of sucrose.
(c) Dextran
Sucrose is biologically converted to dextran by L. mesenteroides, which produces
an enzyme dextransucrase.
FIELD CONTROL OF POST-HARVEST LOSSES
Research efforts to assess the extent of cane deterioration and control its progress
at the field and factory have met with only partial success. Various parameters of juice
quality for the cane arriving at the factory which have been found useful are dextran gum,
oligosaccharides, ethanol, reducing sugars, titrable acidity, invertase content, juice
viscosity, purity drop etc. Based on these indicators quality of cane supplied to the mills
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could be assessed, however, sucrose losses in harvested cane could be minimized by
using methods described below:
(1) There is no substitute for better communication, quick and efficient transport to
minimize post-harvest losses. The harvested cane must be brought to mill and
processed as quickly as possible. The factory management must ensure that fresh
cane is supplied regularly and all indent should be placed accordingly.
(2) The harvested cane obtained for crushing should be made free rom trash, leaves
and roots etc. For late-milling periods, varieties with high rind hardness/fibre
along with high wax content should be preferred. This will reduce considerable
moisture and sugar loss from cane.
(3) Soil content of cane is also one eof the factor influencing not only cane
deterioration but also causes process difficulties, such as cane preparation,
milling, clarification and is a source of millions of microbes that can grow in
juice. Soil also is directly responsible for damage of hammer, knives, Conveyer,
juice screens, pipes and many other parts of the plant. It is therefore, important
that processing of muddy cane should be avoided.
(4) It has been observed that topped cane deteriorates faster than cane with the crown
of leaves attached. In case of any anticipated delay in crushing, topping should be
avoided.
(5) Maturity is a major factor in the inversion and subsequent reduction of stored
sucrose. As maturation level increases the extent of sucrose loss is
minimized. Harvesting of immature or over mature cane should be avoided to cut
down post-harvest sugar losses. It is necessary that maturity-wise harvesting
should be implemented, especially in the low recovery areas.
(1) In order to cut down post-harvest sugar losses, it is important to identify
sugarcane varieties with high sucrose content with less inclination to post-harvest
inversion (both biochemical and microbiological). These varieties should
also be screened for rind hardness, wax content etc.
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(7) The transport and storage of cane also affect the process of dextran formation i.e.
degree of damage from loading equipments, size and shape of container etc.
Excessive mechanization viz. grab loader, chains and slings tend to bruise cane.
(8) In case of unavoidable delay in crushing, the harvested cane should be stored in
small heaps with minimum ground contact and sprinkled with a solution of
bactericide and covered with a thick layer of trash. This method has been found
to suppress the activation of internodal invertases. The cane piles should be
stacked in such a way so as to facilitate proper ventilation.
(1) The cleanliness in the cane yard is of utmost importance. The management
should ensure that first cane in should be first cane out, this will avoid piling up of
stale cane.
(2) Although several disinfectants have been tried in recent past but their practical
use has been restricted by the availability, high cost and sometimes
environmental problems.
Desai et al (1985) noticed that spraying of harvested cane with benzoic acid (100
ppm) and formaldehyde (100 ppm) significantly retarded post harvest losses. Frequent
spraying of solution containing potassium permanganate (0.1%) sodium metasilicate
(1%) on harvested stored cane was found to be much effective in minimizing invertase
activity and retaining the juice quality. The efficacy of this method is further enhance if
cane heaps are covered with trash. This integrated method is "Environmentally benign"
and suitable for Indian conditions.
(3) Recently, a new chemical formulation 'Sucroguard' is being made available in
Indian market to suit Indian conditions and practices of cane harvesting. It was
observed that dipping both the cut ends is far superior method of application
of Sucroguard, and improvements upto 0.9% higher recovery on cane were
obtained. It is also observed that there is about 70 % reduction in microbial
population of the primary juice of Sucroguard applied cane than that of control.
POST-HARVEST LOSS MANAGEMENT : FUTURE POSSIBILITIES
(1) Field control of Leuconostoc bacterium offers an excellent scope to minimize
dextran formation after harvest. Developing a suitable package of nutrients
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containing higher dosage of K and Zn is an interesting area of research in
containing field population of dextran producing bacteria.
(2) There is an ardent need to screen commercial varieties for their ability to
withstand post-harvest stress, especially, to resist moisture loss, inversion and
dextran formation.
(3) A more realistic possibility is to develop a cheap and effective field biocide or
deterioration inhibitor, which may be able to control the growth and
multiplication of Leuconostoc sp. as well as has the ability to minimize
inversion losses.
(4) A strong chemical formulation with broad spectrum anti-microbial activity and
inversion inhibition will find extensive use in the milling tandem to
minimize biological losses of sucrose.
(1) The dextranase system developed in Australia seems to be effective in removing
dextran, however, a thermotolerant dextranase active at high brix may be more
useful for sugar industry.
REFERENCES
Alexander, A.G. (1973). Sugarcane Physiology. Elsevier Scientific Pub. Comp.
Amsterdam. Pp. 412
Chou, C.C. and Wnukowski (1980). Dextran problem in sugar refining : A critical
evaluation. Proc. tech. Sess Cane Sugar Refin. Res. Pp. 1 - 26
Clarke, M.A. (1997). Dextran in Sugar Factories : Causes and Control (Part I and II).
Sugar y Azucar. October/November
Coote, C.J. (1984). Proc. International Dextran Workshop. Sugar Processing Research
Institute. Inc. New Orleans, LA. pp. 70-72
Das, G. and Prabhu, K.A. (1988). Hydrolytic enzymes of sugarcane : Properties of
alkaline phosphatase. Int. Sugar J. 90(1992): 69-71
Desai, B.B., Sangle, P.B. and Gaur, S.L. (1985). Chemical control of post-harvest losses
in sugar cane. Curr. res. Rep. 1(1): 33
Foster, D.H. and Ivin, P.C. (1981). Losses of sugar and water from cane in fires. Proc.
Australian Soc. Sugar Cane Technol. Bundberg (Australia)
115
Hylton,M. (1997) Stale cane:The dextran problem. Sugarcane (Jamaica) 20(4): 1-3.
Solomon, S. (1996). Sugar production in India by 2000 AD. I. Constrains and strategies
for increasing production and production efficiency. Pp. 9 - 11. In : sugarcane
research towards Efficient and Sustainable Sugar Production. (Eds. Wilson, J.R.,
Hogarth, M.D., Campbell, J.A., Garside, A.L. CSIRO, Brisbane-Australia).
Solomon, S., Shrivastava, A.K., Srivastava, B.L. and Madan, V.K. (1997). Pre-milling
Sugar losses and their Management in Sugarcane. Technical Bulletin No. 37.
Indian Institute of Sugarcane Research, Lucknow. pp. 1 - 217
Solomon, S., Shahi, H.N. and Madan, V.K. (1999). AIDS Syndrome affect sucrose
recovery : Cane sanitation must precede mill sanitation (Abs). Proc. Int. Soc.
Sugar Cane Technol. New Delhi
Wold, R.L. (1946). Cane deterioration in a storage pile. Hawaiian Plant Rec.,50(1):5-10
Young, H.E. (1963). The deterioration of burnt standing cane and burnt cut cane.Proc.
Int. Soc. Sugar Cane Technol., 11 : 307 - 311
(Source: Review article by Solomon, IISR, Lucknow, Sugar Tech (2000),
2(1&2): 1 - 18)
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MOISTURE STRESS AND ITS MANAGEMENT IN SUGARCANE
S. VENKATARAMANA & T. RAMANUJAM
Sugarcane is cultivated as an annual irrigated crop in both tropics and sub- tropics
of India. High yielding/high sucrose cane varieties and the environment in which these
varieties are cultivated generally determine sugarcane productivity in India. In India,
sugarcane is grown under widely divergent agro-climatic conditions frequently facing
drought and water logging. This would account largely for low productivity. Moisture
stress associated with high day temperature causes poor growth and high tiller mortality
in both tropics and sub-tropical conditions. Due to the expansion of cane cultivation in
to the relatively less fertile marginal soils combined with one or other environmental
stress, the productivity therefore remained low in all agricultural zones of India. Among
various yield-limiting stresses, major constraint has been the drought. The loss in yield
due to drought has been found to be more than 50%. Farmers in peninsular region
provide optimum level of irrigation and realized maximum return, while in sub-topics the
yield level appears low due to inadequate water management. It has been estimated that
an acre of sugarcane crop receiving 100 acre inches of water through rain and
supplementary irrigation produce 40 tonnes of cane with a water consumption rate of 250
tonnes per tonne of cane. The yield of cane is directly proportional to the amount of
water transpired. Therefore it is desirable to maintain adequate soil moisture through out
the growth period. Accordingly, evolution of sugarcane varieties for drought resistance
and search for genotypes, which possess inherent capabilities of drought tolerance, has
been on the threshold of sugarcane varietal improvement.
SUGARCANE PRODUCTIVITY
The major cane growing areas in the country lie in the sub-tropical belt
comprising the states of U.P., Bihar, Punjab and Haryana which account for about 70% of
the total area and 50 % of the total production. However, the cane productivity of sub-
tropical India is generally low as compared to the tropics where cane yield has touched
even 150 tonnes ha-1. A record yield of sugarcane has been reported at 255 tonnes ha-1
with 42 tonnes ha-1 sugar (22.55 juice sugar) (Ham,1970). Bull and Glasziou (1975)
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predicted a theoretical yield of 288 tonnes ha-1. Further considering light utilization
efficiency, carbohydrate production, respiratory losses, Moore (1987) and Naidu(1987)
derived that sugarcane can yield about 339 tonnes ha-1.
WATER REQUIREMENT AND EVAPOTRANSPIRATION
Total water requirement of annual crop of sugarcane varies from 1250 mm to
2000 mm. Daily evaporation varies from 8-10 mm. Solar energy, wind velocity,
temperature and humidity affect the evapotranspiration. Trials on response of sugarcane
to irrigation suggested that maximum tonnage was obtained at Et/Ep of 0.8. Direct
measurements of soil moisture using resistant blocks, tensiometers and neutron probe are
followed for experimental purposes. Sheath moisture and moisture content of immature
nodes also serve useful index for determining water requirement of sugarcane crop. For
high yield, sheath moisture index should be high enough (83 -85%) at 5th month stage,
and proper drying off with sheath moisture index of about 72% at 12th month is desirable
for higher CCS%.
GROWTH PHASES IN SUGARCANE
Sugarcane crop passes through four distinct physiological growth phases i.e.
germination (o to 60 days), formative (60 to 150 days), grand growth (150 to 240 days)
and maturity (240 to 360 days). Each phase requires a set of specific light, temperature
and water availability. Water requirement of each growth phase of an annual crop is
300mm, 600mm, 1000mm and 600 mm during germination (0-60 days), formative (60 to
150 days) grand growth (150 to 240 days) and maturity (600 mm) respectively. The
optimum temperature for growth is around 30°C. The germination process is very much
dependent on temperature. An aerial temperature range of 26-33°C with soil temperature
of 23-28 °C is favourably suited for initial sprouting and germination of buds. Tillering
and establishment of canopy characterize the formative phase. The optimum temperature
for tillering ranges from 26-33 °C, while higher day temperature in the range of 32-37 °C
has inhibitory effect. Tillering process is highly photosensitive and mutual shading of
leaves and higher interplant competition reduces the tillering. A threshold level of 400-
900 hrs sunshine was found optimum for good tiller production in tropics. Since tillering
coincides with the summer months, adequate water availability should be ensured to meet
the evaporational demands of the crop and to maximize the tiller mortality. The grand
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growth phase is characterized by cane elongation, canopy closure and completion of
vegetative growth. A temperature range of 30-350C with a relative humidity of about
75% is most suitable for grand growth. Rainfall during this growth phase is essential for
higher yields of good quality cane. Sucrose accumulation and maturity follow grand
growth phase. A clear day coupled with 29-370C temperature is helpful for inducing
increased storage of sucrose, lower nitrogen 0 and better quality juice. Fluctuations in
temperature have a negative influence on the enrichment of sucrose. Rainfall during the
maturity period induces a resumption of growth and thus harmful for sucrose formation
and accumulation. Limited water supply, moderately low relative humidity, 7-9 hrs of
sunshine per day, and a temperature of 10-140C favours ripening process.
DROUGHT RESISTANCE IN SUGARCANE
Sugarcane generally experiences moisture stress during the formative phase and
hence reduction in growth associated with yield decline is a constant constraint in
sugarcane cultivation. Various physiological responses have been analyzed and certain
specific parameters have been utilized in a directional breeding programme aiming at
evolving drought resistant cane varieties.
PHYSIOLOGICAL RESPONSES
a) Root system: Extensive root investigations revealed that the sett roots emerge from
the root band (present at nodal region of sugarcane sett), and start growing within 24 hr
of planting. At the third day, some roots extend at a rate of 10 mm/day and by day 5, the
elongation reaches to 20 mm/day. These thin and branched sett roots are replaced by
thick; more fleshy and less branched shoot roots by 90 days age. Rooting depth,
distribution and activity are generally affected by soil water relationships. Generally more
root mass occur at less than 50 cm depth in normally irrigated condition while under
stress, roots penetrate vertically downwards in the form of a rope. The varieties selected
for greater rooting depth suffered the least water deficits as compared to the normally
irrigated plants.
b) Shoot growth: The leaf production steadily increase upto 240 days, and a full ground
cover (LAI=3.0) will be established at around 180 days. When LAI reaches 4-5, more
than 80% of the incident photosynthetically active radiation will be intercepted by the
canopy, which is generally controlled by the foliar arrangement. Rate of canopy closure
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and early development of foliar apparatus are necessary for higher proportion of solar
radiation utilization at active growth phase.
Stalk elongation occurs primarily at grand growth and varieties differ in the rate
of stem elongation. High crop growth types are generally high biomass yielders.
Rostron(1974) calculated that a crop growth rate of 20 g m -2 day would yield about 75
tonnes/ha/y dry matter out of which about 70-80% of the above ground drymass is
accounted by cane stalks only. Dry matter production is generally low during periods of
incomplete canopy development.
The physiological processes such as photosynthesis, respiration, stomatal
dynamics, leaf water potential changes, transpiration etc. function in a coherent manner
to finally determine the yields and sucrose content. Cane elongation is directly related to
water availability and hence stress causes large reduction in stalk number, height, cane
yield and sugar yield. Sucrose accumulation, irrespective of treatment begins at the
bottom of the cane and progresses upward to the top internodes, and by 12 months, the
sucrose % juice attains full genetic potential of a variety.
DROUGHT TOLERANCE MECHANISMS
In sugarcane, drought manifests its symptoms in several ways. The major
attribute is the drying of older leaves and stunted growth of stem, resulting in a dwarf
canopy. The young leaves however remain green under drought stress, but when the
stress intensity becomes severe, the entire crop looses its turgidity and drying will be
hastened as seen in many susceptible varieties. Following stress termination, there will
be a fast revival of leaf growth. However, cane elongation takes longer time in water
stressed crop. Generally sugarcane is a hardy crop and possesses capacity of tolerating
moderate amount of stress by means of morphological adaptations and
physiological/biochemical adjustments. The inward rolling of top canopy, which is seen,
in many tolerant varieties transmits back the irradiance load thus absorbing less quantum
of direct sunlight. Similarly, wax coating on the leaf surface help prevent water loss from
leaf as well as nodal regions of the cane. In addition, various plant responses such as
tissue hydration, stomatal behaviour, water potential changes, stability of enzyme
systems was found to be helpful in imparting drought resistance. Further it was also
identified that less transpiring leaves with low density of sunken stomata, extensive
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vascular bundles in roots and stem possess direct relationship with drought resistance.
Data on regression analysis indicated that number of millable canes, cane height, juice
extraction% and sucrose % cane are the most dominant parameters for yield build up
under stress. Therefore these traits have been used for identifying resistant types. In
recent years, certain biochemical factors such as accumulation of abscissic acid, betaine,
proline and other related chemical compounds were found to enhance the leaf turgidity
and acclimate cane varieties during stress period.
YIELD IMPROVEMENT UNDER DROUGHT
In tropics, the nonavailability of water coupled with summer drought aggravates
the stress effect and eventually lowers the crop yields. The problem of short-term drought
is common in rain fed agriculture, which normally accounts to substantial loss in
productivity. Thus the yield of a variety under stress is its response to stress and inherent
yield potential. Increased yield under stressful environments can be obtained by
modifying cultural practices or by selecting genetically improved varieties. These cultural
practices are costlier alternatives. A slow but long term and ultimately less expensive
objective is to develop stress resistant genotypes. Of late, chemical modification of the
plant to enhance the resistance potential to environmental stress is a possibility that is
currently being investigated. Plant growth regulators offer scope for stimulation of
growth, timely induction of metabolic reactions, modification of internal water relations,
and resistance to environmental stresses. Hence plant breeders have been utilizing large
populations of diverse germplasm for making selections to achieve or to build desirable
traits in present day varieties.
DROUGHT MANAGEMENT
Proper drainage and restricted water management are the essential features to be
considered in ameliorating drought. Maximum cane production could be obtained only
when the crop is not experiencing prolonged moisture stress. Irrigation schedule has to
be planned so as to maintain adequate soil moisture in the root zones. Due to high
evapotranspiration demand during summer months as well during water deficit periods,
the water requirement of sugarcane crop goes up.
Certain management practices such as soaking of setts in saturated lime water,
urea and potash spray (2.5 kg / 100 litres water) during formative phase (60, 90 and 120
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days) helped in mitigating water stress effect considerably. Also, cane trash mulch was
found to increase the rate of tillers and tiller survival. When cane is subjected to stress
during late growth and maturity phase, application of K and mulching the alternate rows
have been found to be highly economical and advantageous in increasing yield and
quality particularly in small and marginal holdings.
CONCLUSION
The strategies for ameliorating drought in sugar production involve varietal
development to suit moisture deficit areas as well as developing suitable cultural
techniques to minimize the yield loss due to drought. How ever for long term
perspectives breeding varieties for drought prone areas and judicial management of
available water are more important. Accordingly, the sugarcane germplasm is being
evaluated for characteristics such as less transpiring leaves, low density of sunken
stomata, extensive vascular bundles in roots and stem curling and inward rolling of
leaves, wax deposition on leaves etc and these traits were utilized in breeding for drought
resistant varieties.
REFERENCES
Bull,T.A. & Glasziou,K.T. (1975) Sugarcane. In: Crop Physiology - Case
Histories(ed.L.T. Evans) pp 51-72, Cambridge Univ.Press, Cambridge
Donald E. Fosket, (1994) Plant growth and development-A molecular approach,
Academic Press, San Diego
Gascho, G.J. & Shih,S.F. (1983) Sugarcane In: Crop water relations (ed. I.D. Teare and
M.M. Peet) John Wiley & Sons,pp 445-479, New York
Naidu,K.M. & Venkataramana,S. (1988) Physiological aspects of yield in sugarcane.
Proc. International Cong. of Plant Physiology, New Delhi, Feb 15-20,1988
Naidu,K.M. & Venkataramana,S. (1989) Sugar yield and harvest index in water stressed
cane varieties. Sugarcane No.6, p 5-7
Naidu,K.M. & Venkataramana,S. (1993) Sugarcane In: Rooting pattern of tropical crops
(Ed. M.A. Salam) Tata Mc Graw Hill (India) New Delhi, pp 169-187
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FLOWERING IN SUGARCANE AND METHODS OF CONTROL
P.N. GURURAJA RAO
Flowering in sugarcane is seasonal and occurs annually during the short days of
late autumn and early winter. Flowering is very common in peninsular India where
during October-November, one can observe sugarcane fields in full bloom. Whereas in
sub-tropical India, sugarcane flowers during December-January.
In sugarcane, flowering is mainly determined by the daylength (photoperiod),
which in turn is a function of latitude. Floral initiation occurs when the plant experiences
photoperiod of 12 h 30 mts. Since the daylength changes with the latitude at the rate of
2.2 days for every degree of latitude, the induction also will be that much later than
equator towards north and earlier towards South of equator. Therefore, sugarcane
flowers throughout year at or near the equator provided all the other conditions are
favourable. Accordingly, the time of floral initiation also differs with location as given
below:
Location Latitude Time of Floral initiation Flowering season
(Time of emergence)
Coimbatore
(Tamil Nadu)
11oN 2nd week of July -
3rd week of August
October-November
Bijapur
(Karnataka)
17oN 3rd and 4th week of August November
Lucknow 26oN 2nd and 4th week of September December-January
In general, the differences in night length (Nyctiperiod) between places are such
that nearer the crops are to be equator, the earlier are their flowering and the critical
period of floral initiation.
Besides photoperiod, flowering is also influenced by several other factors. The
knowledge of the mechanism of flowering and the factors required for flowering is
essential if one has to attempt to control flowering in sugarcane. Some of the factors
influencing flowering in sugarcane are:
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1. AGE OF THE CROP
Sugarcane cannot be induced to flower when it is too young. The minimum plant
age or the physiological "ripeness to flower" stage coincides with the development of 2-4
mature internodes at the base of the stalk. In varieties that flower heavily, this phase is
shorter. This state of ripeness to flower is reached about one month earlier in stalks from
ratooned plants.
2. LEAVES
The leaves of sugarcane plant play a vital role in flowering since the youngest and
most rapidly expanding leaves are the perceptive organs of the photoperiodic stimulus.
When young leaf blades were excised once or twice during induction, flowering
decreased or delayed. This suggested that the flowering stimulus is translocated from the
TVD leaf to the shoot apex.
3. TEMPERATURE
Even at a single location where the natural photoperiods are almost constant from
year to year, the intensity of flowering is highly variable primarily due to annual
fluctuations in minimum temperature and moisture. The night minimum temperature
plays a crucial role; below 18oC, induction is prevented. Sugarcane flowering is reduced
when the daytime temperature (maximum) exceeds 310C at induction. The decrease in
flowering at higher latitudes is primarily due to fewer inductive day-lengths and low
temperatures during the flowering process.
4. MOISTURE
Flowering is quite sensitive to drought. Increased flowering is associated with
high water tables or with soils having a high soil moisture content. The adequate moisture
is critical not only for flower induction and development, but also for timing of
emergence and anthesis. The high temperature inhibition of flowering may also be a
water stress effect.
5. NUTRITION
Flowering was frequently reduced in high fertility soils. Higher levels of nitrogen
especially at the time of induction consistently inhibit flowering. Even the development
of panicle and emergence are inhibited by excess nitrogen.
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Among these factors, temperature and soil moisture determine the time, duration
and intensity of flowering.
CONTROL OF FLOWERING
Flowering is an undesirable trait from the cultivators' stand point. If flowering in
a commercial crop could some how be checked, the farmer stands to gain and realize
more cane and sugar yield. Flowering therefore has profound effects on both cane yield
and quality.
EFFECT OF FLOWERING ON CANE YIELD AND QUALITY
The effect of flowering is mainly related to change in function of the shoot apical
meristem from the production of new leaf and stem tissue to the production of a panicle.
Leaves slowly loose photosynthetic capacity become diseased and senesce which leads to
a respiration loss of sucrose already stored in the parenchyma. A study in Barbados
(13oN) reported a linear relationship between flowering and yield; a loss of 0.47% loss
for each 1% flowering in a plant crop and a lesser 0.28% loss for each 1% flowering in a
ratoon crop. The yield due to flowering is affected by the interaction of flowering with
other factors like time interval and the climatic conditions between flowering and harvest.
The consistent yield losses due to flowering at lower latitudes have stressed the role of
higher temperatures in causing greater yield losses.
Varieties differ in their yield loss after flowering and part of the differences
among varieties could be attributed to pith development. A central column of collapsed
parenchyma tissue (pithiness) invariably develops in the flowered stalks starting from the
upper internodes beneath the peduncle. But greater differences among the varieties seem
to be the result of their ability to form side shoots (lalas), which is a varietal
characteristic.
Immediately after flowering, the stem continues to store sucrose until
photosynthesis declines. Then the stem sucrose itself starts declining. Flowering might
result in an increase, decrease or no change in sucrose yield depending on the interaction
among the time interval, environment between flowering and harvest and the varietal
characteristics. Crop environment may include primarily temperature and adequacy of
water (Soil moisture). The study in Barbados calculated potential sugar loss of 0.05
mt/ha for each 1% of flowering. The differences among varieties in juice deterioration
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after flowering can be considerable. Varieties with less or no deterioration after
flowering may be preferred to benefit the sugar industry.
METHODS OF PREVENTING FLOWERING
Although there are many factors (as described above) which could be potentially
of use in preventing flowering, only a few methods can be incorporated into sugarcane
farming. Prevention measures are feasible only because induction is limited to a brief
period annually. These methods should be easy to use, less expensive and not
detrimental to yields.
In areas conducive to flowering, the best method is to cultivate
low-flowering/non-flowering, non-deteriorating varieties. Keeping this in mind, the
breeders have developed a number of varieties all over the world. If there is no other
option but to grow heavy flowering varieties because of certain other desirable traits,
there are other methods available. Briefly described below are some of the methods of
flower control in sugarcane in commercial fields.
1. GENOTYPE OR VARIETY
Flowering is a genetically determined trait of sugarcane clones. Under ideal
conditions, the flowering may range from 0 to 100 %. Thus, the surest and safest method
for eliminating flowering in commercial fields is to grow non-flowering varieties.
2. CROP AGE
Manipulation of crop age by altering the planting date is one method to control
flowering. Flowering will not occur if plants are too young to be induced during the
photo inductive period. Thus flowering can be avoided in heavy flowering areas by
scheduling the planting or ratooning in such a way that plants were less than 3-4 months
by induction period. This is practicable only when it involves minimal loss of the
growing season.
For example, at Coimbatore, sugarcane planted after may do not flower in
October-November of the same year, but flower in the same moths next year. Flowering
is considerably reduced in April-May planted crop. Certain varieties even escape
flowering in April-May planting. Adsali planting or special season planting (July to
September) of sugarcane is common in some States of tropical India to avoid flowering
and its adverse effects on yield and juice quality.
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3. PHOTOPERIOD
In commercial practice, flowering was prevented and yields were significantly
increased by brief light break applied to break the continuity of night for less than one
month. Though successful, it cannot be practiced on a large scale, since it is highly
expensive.
4. MECHANICAL DEFOLIATION
Sugarcane stalks perceive the photoperiodic stimulus through their top, young and
most rapidly expanding leaves (spindle cluster). If these leaves are removed on the
appropriate date when floral initiation takes place, the plants can be made to miss their
signal and thus skip flowering. This method is totally successful but can be used for
prevention of flowering on small holdings in many parts of the country where agricultural
labour is cheap and easily available. Besides, the growth of the plant is limited thereby
resulting in a considerable loss of cane yield. Hence this method can be dismissed as
impracticable.
5. DROUGHT
Soil moisture is one of the factors controlling the variation in intensity of
flowering from year to year and location to location. Low moisture reduces the intensity
of flowering. This relationship indicates the potential for controlling flowering by
monitoring soil moisture. Imposing drought by withholding irrigation has become a
commercial method for preventing flowering. When irrigation was withheld for one
month prior to induction period, flowering was reduced or prevented entirely with little
permanent injury to the crop. The additional benefits of this method are saving of water
and labour.
This method of controlling flowering by withholding irrigation cannot be used in
several parts of the country simply because the monsoon occurs during the period of
floral initiation. In Tamil Nadu, where north east monsoon (October-December) is the
main monsoon season, withholding of irrigation during floral initiation period reduced
flowering considerably in some of the late season flowering varieties like Co 419, Co
658, Co 740, Co 6304, Co 6806 and CoS 510.
6. CHEMICALS
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In view of one or the other disadvantage of the above-mentioned methods, the
application of chemical is more feasible for inhibition of flowering in sugarcane crops
under our conditions. A number of chemicals have been found to reduce flowering while
at least half a dozen of them were used on a commercial scale. The first chemical used
for flower control on a large scale was Maleeic hydrazide. Later, the substituted ureas,
Monuron (CMU, 3-(p-chlorophenyl)-1, 1 dimethyl urea) and then Diuron (DCMU, 3-
(3,4-dichlorophenyl)-1, 1 dimethyl urea) proved equally effective. They were ethen
replaced by herbicides, gramoxone (Paraquat, 1, 1-dimethyl 4-4'-bipyridinium salt) and
reglone (Diquat, 6,7-dihydropyridol (1,2-9:2',1'-C) pyrazidinium salt). Diquat has been
used on a large scale for the first time in Hawaii in 1970's. The effectiveness of diquat
for control of sugarcane flowering depended critically upon the date of application.
Diquat applications 1 week before or after the optimum date were less than 50%
effective. The optimum date for application varies with varieties and hence each variety
is to be tested individually for its flowering response to diquat.
Experimental studies at Sugarcane Breeding Institute have shown that flowering
can be totally checked in late-season flowering varieties with 225 g of Diquat or 175 g of
paraquat per hectare applied 2 times at 3-4 day intervals, resulting in increased cane yield
as well as sugar yield.
The search for a still better chemical however continued since all the chemicals
described above severely suppressed the growth and the amount of flower control also
varied. In the early 80's, promising results were obtained with ethephon (2-chloroethyl
phosphonic acid), an ethylene-releasing compound. Unlike diquat, ethephon was found
to be active over a wide range of application dates. In addition, ethephon was less
phytotoxic, stimulatory to growth and did not desiccate the crop canopy. The activity of
ethephon was less affected by date of application. This would be advantageous since
adverse weather and limited availability of the spray equipment are the critical factors
during the brief flower induction period.
In Hawaii, on an average across locations and genotypes, ethephon reduced
flowering from 25.6% to 5.7%. Ethephon-treated plots also increased sugar yield by 3-7
mt/ha, the increase in sugar yield was primarily due to an increase in cane yield.
Experiments at Sugarcane Breeding Institute during 1986-89 also indicated that ethephon
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applied at 0.25 kg/ha suppressed flowering by 50-100% in profuse flowering varieties
and resulted in an increase of cane yield by 10% and the sucrose content by 2.5 to 6% at
14th month coinciding with March-April.
The beneficial effect of suppression of flowering can be seen more in tropics,
where cane continues to grow throughout the year. Whereas in sub-tropics, the sugarcane
growth practically ceases at the time of flowering or even before when the cold season
sets in. If the cane crop is harvested soon after flowering, there can be no loss in yield as
compared to non-flowered crop, since the loss occurs only in the ensuing months.
Harvesting of flowered crop is therefore not harmful if the cane is harvested within 3-4
months after flowering.
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NEW IMPLEMENTS IN SUGARCANE CULTIVATION
S. RAJAMOHAN
Sugarcane is one of the most important commercial crops cultivated in India in
about 4.076 m.ha., occupying the field for a full year and ratooned subsequently after
harvesting the plant crop.
Being a labour intensive crop, the farmers have to incur a huge expenditure for
carrying out the field operations, viz, ridges and furrows making, planting, weeding,
partial and full earthing up, detrashing, harvesting, ratooning, etc.
The availability of agricultural labour is decreasing over the years due to
migration to other remunerative sectors. The efficiency of the labour available is also
dwindling due to so many factors. Unless the sugarcane cultivation is mechanized, it
would be difficult to continue this profession in the coming years. What had been done
so far in this regard is inadequate.
In Sugarcane Breeding Institute, few tractor drawn implements have been
developed and field tested for mechanizing some of the field operations mentioned above
which are very efficient, cost effective and can cover large area in a day.
ADJUSTMENT IN THE TRACTOR
A 45 H.P. Tractor is ideal for sugarcane field operations. The tractor as such
cannot be used for operating these new implements in sugarcane planted in the ridges and
furrow system formed with three feet spacing. A small adjustment has to be made in the
tractor wheel`s position. The rear wheels should be reversed and the front wheels drawn
outwards so that the distance between the two tyre centres of the front and rear wheels
become six feet. Now the tractor is ready for hitching the implements
NEW IMPLEMENTS AND ITS USES
SBI SUGARCANE PLANTER
The SBI Sugarcane planter is an improved device to help the sugarcane farmers
of this country for taking up planting in an efficient manner, especially in heavy soil
conditions. By using this device, more area can be planted in a day; there will be
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considerable saving in labour; cost-effective; very simple in design; easy to adopt and
affordable by sugarcane growers.
In the existing planters, there are unwanted attachments like Setts treatment unit
and fertilizer application attachment. These are unwanted in the sense that the setts used
for planting need to be immersed in a fungicide solution for a specified period of time for
effective control of seed-borne pathogens and sugarcane is not applied with nitrogenous
and potash fertilizers at the time of planting . The superphosphate to be applied as a basal
dose can be broadcast over the field just before planting.
Only two rows are planted on a single run in the present models while this
improved version will plant cane setts in three rows, thus covering 50 % more area in a
day.
The two ridgers in the available models are smaller and lighter in weight and can
be used only in light soil conditions in contrast to the three heavier and optimum sized
ridgers in the new model and is suitable for heavy type of soil also, which form a greater
percentage of sugarcane area in India.
Comparing the present planters, the setts are planted deep which will prevent
lodging of crop at grown up stages.
Uniform row spacing of three feet can not be maintained in the present art
whereas the new planter is provided with a marker with which it is possible to keep the
rows exactly three feet apart. This facility will play a great role later for intercultivation
by tractor drawn implements.
The objective of designing the new planter is to overcome the above mentioned
defects and to provide the farmers with an improved sugarcane planter so that they need
not depend heavily on manual labour, the availability and efficiency of which is declining
fast over the years due to so many factors and for timely planting in an easy, quick and
efficient manner.
The SBI SUGARCANE PLANTER comprises of three heavy ridger bodies
with a suitable frame for opening three deep furrows (about 12 inches) even in heavy
soils, a seed-hopper to keep the treated setts, three setts dropping units to guide the
dropped setts, three seats for men to sit and drop the setts, three pairs of tynes to cover the
dropped setts with soil, three metal rollers for compacting the soil over the setts and a
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marker on either side to mark the next third feet row. Apart from the above, it is having
the standard attachments for hitching with a tractor.
WORKING OF THE PLANTER
The planter is hitched to a wheel adjusted 45 H.P. tractor. The setts treated in
fungicide solution are loaded in the seed hopper. Three labour will sit over the seats
provided. The tractor is slowly run and labour will have to take the setts from the hopper
and drop them continuously in the sett dropping units. The setts will be placed in deep
furrows opened by the ridgers and covered with soil automatically by the tynes provided
for the purpose and then compacted with the iron roller fitted behind the tynes. The
marker attached to the device will itself mark the next third feet line over which the
tractor's front wheels have to run while returning after reaching one end of the field.
Thus planting has to be continued till completion of planting.
ADVANTAGES
1. Planting in three rows, covering 50 % more area than the existing two row
planters. Planting can be done in about 1.25 ha/day.
2. Suitable for heavy as well as light soil conditions.
3. Deep planting of setts will prevent lodging of canes.
4. Uniform row spacing of three feet could be maintained which will facilitate
intercultivation by tractor drawn implements.
5. Very simple in design and easy to adopt.
6. Highly labour saving and very efficient.
7. Affordable to sugarcane growers.
SBI FOOT-PATH CUM CHANNEL MAKE
The SBI Foot- path cum channel maker is an agricultural device that will help the
research institute farms under gardenland-irrigated conditions adopting ridges and furrow
system of planting. A footpath with channels on either side is formed in between the
blocks. The path is being used by the field workers often during the crop season for
having easy access to each row of the crop for scientific observations, recording data,
sampling, selfing, crossing, harvesting and keeping the produce, etc., The channels are
for irrigating the crop.
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In the known art, the blocks, channels and foot- path areas are measured, peg
marked on the two edges of the field, tied with a coir/plastic rope and the soil in the
channel portion is removed and placed over the foot path area with the help of spades by
engaging human labour. It is a time consuming, inefficient and costly field operation. As
it is being carried out by labour with spades, the process is very slow. Since the labourers
are in different age groups, knowledge, physical health condition, etc., the channels and
path formed are not always straight and uniform in size, shape and depth, sporting a bad
appearance and causing inefficient irrigation.
This particular area has to be kept always clean throughout the crop season.
Unfortunately, this is not possible and many times infested with weeds and the purpose of
providing a path is not served. Once the crop establishes, the weeds may
disappear/reduce inside the blocks due to shade effect. But since the footpath and
channel areas are possessing all the required elements, viz., moisture, space, sunlight and
no competition from the crop, there is bound to be good growth of weeds always. These
weeds are manually weeded with hand hoes/spades superficially. The monocots reappear
immediately. Any herbicide that can be applied to control these weeds may not be
compatible to the main crop. Hence mechanical control of weeds is a necessity.
The objective of this invention is to devise a mechanical device drawn by a tractor
to overcome the above mentioned defects and to provide the research farms a solution to
make foot paths and channels without using manual labour in a straight and uniform
manner, to reform them at anytime whenever the weeds appear, to reduce the cost of this
operation substantially and lastly to cover large area in an day in an easy and efficient
manner.
The foot-path cum channel maker consists of two heavy bodied ridgers with a
suitable frame for making channels, a height adjustable levelling board in between the
ridgers to level the foot path area, a roller for compacting the soil with a scrapper to
remove the sticking soil in the roller.
WORKING OF THE IMPLEMENT
In a 45 H.P. tractor, this device is to be hitched and the levelling board lowered to
required level. The blocks are measured and marked with pegs leaving a space of six feet
for the footpath and channels. A rope is tied on one side of the block to guide the driver
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to go straight across the ridges and furrows formed already. Now the tractor is operated
from one end to the other across the ridges in a slow and steady manner along the rope
already tied.
The irrigation channels having uniform size, shape and depth will be formed by
the ridgers, the path levelled by the levelling board and the loose soil in the path area
compacted by the roller. If required, the levelling board can be either raised or lowered
according to the field condition like soil moisture, tilth, etc., While running, if pot holes
appear in the foot path, the levelling board should be lowered and if the height of the path
is suppressed and large soil portion accumulate before the levelling board, then the board
must be raised.
Thus, a footpath with channels on either side is formed in a few minutes from one
end to another end of the field easily and continued in between other blocks in the same
way. Among the two channels formed this way, one can be used for irrigation according
to the slope of the field and the other to prepare sub-plots for every five or six rows with
a spade by engaging very minimum labour, say one or two per acre.
ADVANTAGES
a. The cumbersum process of manual work is completely eliminated. Paths and
channels are formed with ease.
b. Very cheap when compared to labour cost.
c. Very quickly done and can cover large area in a day.
d. Very efficient in regard to size, shape and depth of channels, facilitating good
flow of irrigation water which is difficult to ensure if performed by labour.
e. This area can be kept always clean by using this implement repeatedly as and
when infested with weeds.
f. The design is very simple and easy to adopt.
SBI INTERCULTIVATOR
The SBI intercultivator is an agricultural device drawn by a tractor to help the
sugarcane farmers of this country for removing weeds mechanically in between crops in
the ridges and furrow system of planting.. While operating in sugarcane fields, the crop
will not be damaged whereas the weeds in between the rows could be controlled in more
area in a day very effectively and at a very minimum cost.
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There is no mechanical device operated by a tractor for intercultivation and
weeding in sugarcane grown in ridges and furrow system. The weeds are removed
manually with hand hoes or spades by engaging human labour. Sugarcane being a long
duration crop needs a minimum of two to three weedings during the crucial first 90 days
of crop growth. Apart from the fact that, manual weeding being a costly proposition,
sufficient labour force is not available for carrying out agricultural operations in time
during the recent past and the situation is going to be still difficult in future.
The objective of designing this implement is to avoid the costly, tedious and slow
exercise of manual weeding and to provide the farmers with a new implement viz., SBI
Intercultivator so that they need not depend heavily on local labour, spend more on
weeding and to carry out the operation in a quick and efficient manner in time and in
relatively larger area in a day.
The SBI intercultivator consists of three sets of triangle shaped tynes with three
tynes in each set attached to a frame which is sufficiently raised from the ground level to
avoid damage to the crop while running in between the rows. There is a heavy pipe
provided over the frame to add enough weight to the device to have sufficient penetration
by the tynes. The device is also provided with standard tractor hitching attachments.
WORKING OF THE INTERCULTIVCATOR
The SBI intercultivator is hitched to a wheel adjusted 45 H.P. tractor, brought into
the field and placed in such a manner that the three tyne sets rest on the ridge in between
the rows. The tractor is moved slowly lowering the hydraulic to required depth to break
the ridges and to remove the weeds. If the device is operated for the second time, the
effect will be very good. The tractor could be operated faster during the second run. The
weeds in between the crop rows will be completely uprooted.
ADVANTAGES
a. Weeding can be done in one hectare in a day.
b. Owing to the triangle shaped tynes, the underground tubers of monocot weeds
are uprooted which is impossible when the weeding is carried out manually with spades
or hoes.
c. The areas in between the crop rows are loosened well ensuring better aeration
for the young roots.
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d. Very cheap, faster and efficient as compared to manual weeding.
SBI EARTHING UP RIDGER
The SBI EARTHING UP RIDGER is an implement to help the sugarcane
growers for earthing up the plants and covering the applied fertilizer during 40-45 days
and 80-90 days of age of the crop, hitherto performed manually which is a laborious,
costly, time consuming and inefficient method.
There is no mechanical device available at present for this purpose and is being
carried out manually with spade by engaging labour. The fertilizers are first applied by
hand in between the crop rows and then earthing up is done with spade for the purpose of
covering the applied fertilizer and to provide anchorage to the plants. Only very limited
area could be covered in a day by manual earthing up. As it is being performed by many
labourers varying in age, experience, knowledge, physical health, etc., the work turned
out may not be uniform resulting difficulty in irrigation.
Therefore the need to devise a device to overcome the above mentioned defects
and to provide the farmers with a simple implement so that they need not depend heavily
on manual labour, the availability and efficiency of which is dwindling over the years and
to carry out earthing up timely, cheaply and efficiently, was felt necessary.
This implement consists of two heavy ridger bodies with a suitable frame and
standard hitching attachments.
Working of the implement
The implement is attached to a wheel adjusted 45 H.P. tractor. This field
operation is done first on 40-45 days and then on 80-90 days after planting. Urea and
Muriate of Potash are mixed in required quantities and applied as a band in the middle of
the furrow. The tractor is placed in the field in such a manner that the wheels are
standing on the first and third furrow and the hydraulic lowered to required level. The
tractor is moved forward. The ridgers while moving forward will split the soil in between
the crop rows and form the ridges along the crop rows, thus covering the applied fertilizer
and earthing up the plants simultaneously. The operation is continued and earthing up
done in alternate rows on each occasion.
ADVANTAGES
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1. The earthing up operation hitherto performed by manual labour can be dispensed
with, thus highly labour saving.
2. About 1.00 to 1.25 ha area can be earthed up in a day as compared to manual
labour.
3. Plants are earthed up upto one-foot height, which provides good anchorage
to plants preventing lodging.
4. The furrows are uniformly deep, facilitating free flow of irrigation water.
5. Small weeds are smothered by soil.
6. The device is simple, easy to adopt and affordable
SBI OFF-BARRER
The SBI OFF-BARRER is an implement to help the sugarcane farmers for
carrying out the field operation of off barring for a ratoon crop hitherto performed
manually.
There is no mechanical means available now for the above said purpose and
performed manually with spade by engaging human labour. After removing/burning the
trash left over in the field during harvesting the plant crop and giving copious irrigation
to the field, the fertilizer mixture is broadcast over the field by hand and the sides of the
ridges are broken with the spade. This is a labour consuming, slow, costly and
inefficient process. The farmers have to incur a huge expenditure on this account.
To provide the sugarcane farmers with a simple device so that they need not
depend heavily on human labour and to carryout the off-barring operation easily, cheaply,
efficiently and in more area per day, this implement was designed.
This device consists of three sets of tynes with two tynes in each set attached to a
frame and standard tractor hitching attachments.
WORKING OF THE IMPLEMENT
Urea and Muriate of Potash fertilizers in required quantities are mixed and applied
as a band in the middle of the furrow. The device is hitched to a wheel adjusted 45 H.P.
tractor and brought into the field and placed in such a manner that the wheels are in the
first and third furrows. The tractor is moved forward after lowering the hydraulic to the
required level. The tynes will cut the sides of the ridges without uprooting the cane
stubbles.
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ADVANTAGES
a. No need to engage manual labour; highly labour saving and inexpensive
b. About 2.00 ha area can be covered in a day.
c. Operation can be done timely.
e. The device is simple, easy to adopt and affordable by ryots.
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SUGARCANE DISEASES AND THEIR MANAGEMENT
P. PADMANABAN AND N. PRAKASAM
The importance of diseases as a constraint in the production and productivity of
sugarcane is well recognized. It is estimated that loss caused by disease range from 10 to
25 per cent.
Diseases of sugarcane are caused by different kinds of pathogens viz. fungi,
bacteria, viruses and mycoplasma. Among fungal diseases red rot, smut, wilt and sett rot
are important. Besides these, bacterial leaf scald, mosaic (caused by virus) and grassy
shoot (caused by mycoplasma) are potential diseases, which can cause considerable
damage.
1. RED ROT
Red rot disease caused by Colletotrichum falcatum Went is the major constraint
for sugarcane cultivation in most parts of India. The disease was responsible for failure of
most important varieties like Co 419, Co 997,Co 1148, Co 7717, CoJ 64, CoC 671 and
CoC 92061. It continues to be a serious threat to the Indian sugar industry particularly in
the states of Tamil Nadu, Andhra Pradesh, Orisa, Gujarat, Rajasthan, Punjab, Haryana,
U.P and Bihar (Alexander and Viswanathan, 1996).
The disease is primarily caused through infected setts. The secondary spread of
the disease occurs during monsoon period when high humidity condition prevails.
Sporulating conidia at the nodal portion of the susceptible canes are carried through rain
splash and irrigation water to the adjoining cane / area resulting in secondary spread.
Fresh surviving debris of red rot inoculum also serves as a source for further spread of the
disease. Red rot disease can be managed by following integrated approaches as
mentioned below.
i. Setts should be selected from red rot free area in order to eliminate primary source
of infection.
ii. Movement of red rot infected canes from red rot prone area to red rot free area
should be prevented through domestic quarantine legislation.
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iii. If primary infection is noticed, the infected stools should be destroyed
immediately.
i.If the plant cop in infested by red rot, it should not be ratooned.
v. Red rot infected plant crop should be harvested on a priority basis to prevent
secondary spread.
vi. Red rot infected sugarcane fields should be rotated with paddy crop to destroy
surviving debris borne inoculum in the field.
i. .Red rot resistant varieties viz. Co 8021, Co 7704, Co 86010, Co 86011,
Co 86249, Co 93009, CoG 93076, CoSi 95071 and CoV 92102 (Tropical).
Co89003, Co93026, Co 97017, Co 98015, CoH 101, CoPant 94211, CoS 8432,
CoS 8436 and CoS 96208 (Sub tropical) can be grown in red rot endemic areas.
2. SMUT
Smut is an important fungal disease which causes yield and quality loss in sugarcane.
It is widely prevalent in South India especially in parts of Karnataka, A.P and
Maharashtra. The wonder cane of Maharashtra Co 740 is highly susceptible to this
disease. The disease is primarily transmitted through infested setts and secondary spread
occurs through wind borne teliospores of the smut fungus. In Tamil Nadu a popular
variety CoSi 95071 is highly susceptible to smut disease.
By proper seed selection, roguing of smut-infected clumps, avoiding ratoons of plant
crop with moderate smut infection, the disease can be easily managed. Setts from smut-
affected fields should be treated in hot water at 50 oc for one hour or 52oc for 1/2 hour
along with systemic fungicide Bayleton (Tridemephon) at 0.1 % concentration to
eliminate the sett borne infection (Padmanaban, et al., 1987). The fungicide hot water
treated setts should be raised as part of healthy seed nursery programme and distributed
to farmers.
Varieties, Co449, Co 527 and Co 6806 are consistently resistant to smut disease.
3. SETT ROT
Sett rot is caused by the fungal pathogen Cerotocystis paradoxa. The disease is
common in germinating setts. The disease is primarily spread through soil borne
innoculum under ill-drained conditions. The fungus infects the setts mainly through the
cut ends and slowly spreads to the entire parenchyma tissues. Sett rot infected setts fail to
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germinate leaving lot of gaps in the field. In the early stage of rotting stinky odour of
pineapple is emitted due to production of ethyl acetate and it helps in identifying the
disease. Sett treatment with systemic fungicide viz. Bavistin at 0.1 % concentration is
found effective in controlling the sett rot infection. Providing adequate drainage in the
field will also help in avoiding the disease.
4.WILT
The disease is associated with fungi Fusarium sp. and Cephalosporium sacchari and
the syndrome is predisposed by biotic and abiotic stress factors. Wilt fungi are weak soil
borne pathogens. Abiotic factors like drought, water logging, drought followed by water
logging weaken the root system and predisposes the plant for wilt infection. Subterranean
soil pests like white grub, root borer and nematode and insect pests like mealy bug, scale
insect, fungal pathogen like red rot weakens the plant and root system paving the way for
wilt infection.
Elimination of biotic and abiotic stress factors will reduce the wilt incidence. Wilt
can be effectively managed by using healthy setts, crop rotation with paddy and by
application of organic manure in order to increase the antagonistic flora, which can
suppress wilt pathogen present in the soil.
5. GRASSY SHOOT DISEASE (GSD)
The disease is widely prevalent in all parts of India. It is mainly transmitted
through infected setts. Proutista moesta, a derbid bug has been reported to transmit this
disease. The disease is caused by a Mycoplasma like organism (MLO). GSD can cause
very heavy yield loss particularly when planting material is obtained from infected
sources. Yield losses in ratoon reach their maximum in crops in which primary infection
appeared early in the plant crop.
GSD can be eliminated from infected setts by treating the setts in aerated steam
therapy (AST) at 50o C for one hour. Roguing and eradication of GSD clumps are very
much helpful in the reduction of GSD. Plant crop with high level of GSD should not be
ratooned.
6. MOSAIC
Virus causes Mosaic disease. The primary spread of the disease is through
infected setts. Secondary spread of the disease is through aphids viz. Rophalosiphum
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maidis and Longuinguis sacchari. Only mild strains of mosaic are prevalent in India.
Yield loss caused by mosaic is negligible since only mild strains are prevalent in India.
However surveillance is required to spot out severe strains of mosaic.
7. RATOON STUNTING DISEASE (RSD)
The disease is caused by the bacterium Clavibacter xyli sub sp. Xyli. The disease
is aggravated by abiotic stress like water logging and drought. The variety Co 419 that
was widely cultivated in Northern Karnataka is severely infected by RSD. It causes
severe yield loss in ratoon crop. The disease can be effectively controlled by hot water
treatment of infected setts at 50o c for two hours.. Cane cutting knives should be dipped
with one per cent Dettol or one per cent Lysol to prevent secondary spread of the disease
through cutting knives. Disease free seed should be used for planting.
8. LEAF SCALD
This is a bacterial disease caused by Xanthmonas altilineam. It is widely prevalent
in the varieties CoC 90063 and CoSi 86071 in coastal Tamil Nadu (Viswanathan
et al., 1998). It has also been reported in severe form in pockets of Andhra Pradesh and
U.P.(Agnihotri, 1963). The disease is mainly transmitted through infected setts.The
mechanical transmission by implements that are used for cutting infected stools is also
possible.
Disease free seed material should be used for effective management of the
disease.
INTEGRATED MANAGEMENT OF SUGARCANE DISEASES
Integrated management of sugarcane diseases involve care in seed material such
as seed selection, sanitation, seed treatment and seed multiplication; manipulation of
agronomic practices like field sanitation, adjustment of planting schedule, roguing, crop
rotation, irrigation and fertilizer management; and use of chemical methods such as sett
treatment, soil drench, foliar sprays and pest /vector control etc. All the above are super
imposed on a resistant or tolerant variety. Seed certification, quarantine and legislative
control are also other aspects to be integrated for effective management.
A. SEED SELECTION
Red rot, smut, GSD, RSD and Leaf scald are primarily transmitted through setts
and hence seed selection will help in reducing transmission of these diseases
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considerably. In case of red rot, seed materials should always be selected from red rot
free areas. Any crop with > 5% smut disease or >2% GSD incidence is unsuitable for
seed purpose.
B. FIELD SANITATION AND CULTURAL PRACTICES
Fields without any recent history of red rot, smut or wilt are ideal for planting
sugarcane. Deep ploughing exposes sub-soil to solar radiation and significantly reduces
inoculum load of the pathogen. Restricting the flow of irrigation water from diseased
fields to healthy fields go a long way in containing red rot. Improving drainage
conditions will reduce the severity of foliar diseases. Drought and waterlogging are the
predisposing factors for wilt infection.
C. ROGUING
Timely roguing and eradication of red rot and smut-affected clumps reduce
pathogen inoculum and check secondary spread of disease. All crop refuse and debris of
affected clumps should be burnt. Roguing and eradication are also effective in reducing
the secondary transmission of GSD, RSD and leaf scald.
D. RATOON MANAGEMENT
Diseases like red rot, smut and GSD build up rapidly in the ratoons. Hence the
ratoons should be critically monitored for these diseases and wherever there is high
disease incidence in plant crops, ratooning should be shunned.
E. CROP ROTATION
Crop rotation has been found quite effective in containing red rot where the
residual inoculum has the potential to survive for considerable duration in soil.
Introduction of a rice crop between successive sugarcane crops eliminates red rot
pathogen through anaerobic soil conditions and hence strongly recommended in red rot
endemic areas.
A. HARVEST MANAGEMENT
Severely diseased crops in maturity phase may be harvested ahead of schedule on
priority basis to eliminate the inoculum and chances of secondary spread. The stubbles
of such crops are also uprooted and destroyed.
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B. THREE TIER SEED NURSERY PROGRAMME
It is a systematically developed procedure for management of disease in the
sugarcane area of each factory, using heat treatment. The entire area of the factory is
divided into 5 equal parts each one being a sector. In the first year one per cent of the
first sector is planted with primary seed after heat treatment. This is critically monitored
for diseases and diseased clumps if any systematically rogued. At 7 months the crop is
harvested and is used to plant 1/10 of the first sector area. Simultaneously the second
sector is side by side planted with primary seed. The rate of multiplication of seed cane
is 1 to 10. In the third year the secondary seed nursery of the first sector provides the
commercial seed for the general planting of entire remaining area of first sector.
Simultaneously the secondary seed of the second sector and primary seed of the third
sector are planted. Thus in five years all the five sectors of the factory are saturated with
disease free seed. At every stage there could be slow disease build up due to secondary
spread escapes. Hence in order to constantly maintain the disease level below the
economic threshold levels the entire area is replaced with freshly produced heat treated
disease free seed material once in every five years by repeating the cycle.
The schematic schedule of production and utilization of the disease free seed cane
in the 3-tier seed nursery programme is illustrated in Annexure 1.
A. CHEMICAL CONTROL
The sett rot disease can be controlled by fungicidal dip of setts in 0.1%
carbendazim for 10 min. prior to planting.
B. CULTIVATION OF RESISTANT VARIETIES
By far the most effective measure in the long term management of major
sugarcane diseases is use of resistant varieties for cultivation. Varieties viz. Co 8021, Co
7704, Co 86032, Co 85019, Co 86010, Co 86249 and Co 93009 are tolerant to red rot.
Co 6806 and Co 449 are resistant to smut.
C. QUARANTINE
All seed crops which are proposed to be transported to disease free locations are
to be systematically examined for prevalence of major diseases and only after such
verification and freedom from diseases, such seed material should be permitted to be
transported to disease free areas. Before distributing the cane from such seed material
144
nursery crops should be raised in carefully monitored quarantine farms and only after
confirming that such crops are free from all seed transmitted diseases these crop can be
used as seed cane for general cultivation.
CONCLUSION
Application of information discussed above and its utilization in a comprehensive
manner will be of much use for the efficient integrated management of sugarcane
diseases reducing the crop loss caused by them and thereby increasing the production and
productivity of the crop.
REFERENCES
Agnihotri V.P.(1963) Diseases of sugarcane. Oxford & IBH Publishing Co Ltd. New
Delhi, pp 363.
Alexander K.C. and R.Viswanathan (1996) In sugarcane germplasm conservation and
exchange (Eds. Crogt.B.J. Piggin C.M. Wallis. C.S. and Hogarth P.M.) ACIAR
Proceedings. No 67.Canberra. pp.46-48
Padmanaban P. Alexander K.C. and Shanmugam N. (1987) Effect of hot water treatment
and fungicide on the control of smut disease of sugarcane. Sugarcane Spring
supplement. 13-14.
145
INTEGRATED PEST MANAGEMENT IN SUGARCANE
S.EASWARAMOORTHY
1. INTRODUCTION
Sugarcane is an important cash crop in India. It is cultivated under diverse agro-
climatic conditions ranging from tropical Peninsular India with a moderate climate to the
sub-tropics characterized by extremes of weather. The productivity of sugarcane is
affected by various factors like environmental stresses, nature of crop husbandry and
attack by pests and diseases. The pests inflict considerable losses in sugarcane and sugar
yields. The loss is estimated to be around 20 per cent in cane yield and 15 per cent in
sugar recovery (Avasthy, 1983). This necessitates the adoption of methods in an
integrated strategy to regulate the pests below economic injury level, taking into
consideration the ecological, economic and social acceptance.
2. SUGARCANE ECOSYSTEM
Sugarcane ecosystem has several unique features compared to other cash crops in
India. The physical characteristics of the sugarcane crop limit the use of chemicals
against pests infesting the stem once the canopy has closed and the practice of ratooning
limits opportunities for applying insecticides against root feeders. Thus control
measures against different group of pests often tend to be incomplete and integrated
control is generally practiced without deliberate effort (Fewkes and Greathead, 1978).
Consequently the insecticide pressure is less in sugarcane, compared to other cash crops
in India. In fact, only 2-3 per cent of the total insecticide used in India has been utilized
for control of sugarcane pests (Balasubramanian, 1988). As a result unlike in other crops
the ‘disaster phase’ has not been reached in sugarcane.
2.1. PEST COMPLEX
Though more than 200 species of insect pests infest the sugarcane crop (David
and Nandagopal, 1986), only a dozen pests are economically important. There is much
variation in the geographic distribution, status, number of broods, period of activity and
population build-up of these pests. Generally the pest problem are more in sub-tropical
146
India with regard to the number of species and intensity of infestation by different pests.
The major pests of different agro-climatic zones are given in Table-1.
Table 1: Major pests of sugarcane in different agro-climatic zones of India
No. Climate zone Major pests
1. Humid north - Western Himalayan zone
Negligible area under cane cultivation, No major pests.
2. Himalayan foot-hills Top, shoot and stalk borers; Pyrilla, black bug and whitefly.
3. Humid high rainfall North eastern zone
Stalk, shoot, Plassey and pink borers and Pyrilla.
4. Humid Assam, Bengal zone
Shoot, stalk and Plassey borers, Pyrilla; scale insect and whitefly.
5. Sub-humid and humidSutlej - Ganga alluvial zone
Top, shoot, stalk, Gurdaspur, green, Plassey and root borers, scale insect, Pyrilla, black bug, white flies, white grub and termites.
6. North-Western Semi-arid And arid zone
Top, shoot and pink borers; Pyrilla, scale insect, black bug, white grub and termites.
7. Central semi-arid Vindhyam zone
Top, shoot and pink borers; Pyrilla, scale insect, whiteflies, termites and white grubs.
8. High rainfall, high run off Chotta-Nagpur plateau and adjoining areas of West Bengal and Orissa.
Termites, shoot, top and Plassey borers and Pyrilla.
9. Assured rainfall, deep Black soil malva plateau And Narmada basin.
Shoot borer, scale insect and Pyrilla.
10. Chhatisgarhy plateau zone Shoot borer and Pyrilla
11. Variable rainfall south Central Deccan Plateau zone
Root borer, Pyrilla, scale insect and white flies.
12. South Eastern brown red
Soil zoneShoot and internode borers, scale insect Pyrilla and white flies.
13. Southern variable rainfall, mixed soil zone
Shoot and internode borers, scale insect and white grubs.
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14. Southern bimodal rainfall zone
Shoot and internode borers, scale insect and white grubs.
15. Eastern Coromandal Coastal zone
Shoot and internode borers, scale insect and Pyrilla.
16. Western Malabar Coastal zone
Shoot borer and scale insect.
2.2. NATURAL ENEMY COMPLEX
A large number of natural enemies occur in the sugarcane ecosystem (David and
Easwaramoorthy, 1986) and their activity results in the regulation of pest population
below economic injury level in several occasions. In the absence of these natural
enemies, the losses due to pests would have been several folds. Unlike other crops like
cotton, the strategy for IPM in sugarcane is to conserve and maintain the naturally
occurring biological control so that the insecticidal application are kept at the lowest
level.
Sugarcane, being a C4 plant, is highly efficient in biomass production. Because
of this and the long duration of the crop, it is able to compensate for the damage inflicted
by several pests to a certain extent over a period of time. For example, studies
conducted in a number of centres in India with three varieties viz., Co 313, Co 356 and
Co 421 show that there is extra tillering following shoot boer attack in all the three
varieties, the order of effective compensation being 1.84-116.61 per cent. The
compensating ability of the plant results in a higher economic threshold level for several
pests. For instance, it is 15.0 (Seshagiri Rao and Krishnamurthy, 1973) to 22.0 per cent
(Subba Rao, 1972) incidence for shoot borer, 28.5, 12.2 and 6.2 larvae or 28.39, 24.4 and
17.15 bored internodes per row of 6 metre low length with an interrow spacing of 90 cm
for varieties CoJ 64, Co 6806 and Co 6304, respectively, for internode borer
(Nandagopal, 1963) and 3-5 nymphs/adults per leaf for pyrilla (Pawar, 1983).
3. COMPONENTS OF SUGARCANE IPM
Some of the components like host plant resistance and biological control simply
optimize the naturally occurring phenomena of insect control while other components
148
like cultural, mechanical and chemical control are artificial. In integrated pest
management, all or most of the components are to be blended in a harmonious manner
with minimum disruption to the ecosystem.
3.1 HOST PLANT RESISTANCE
The development and use of resistant varieties, which possess other economic
traits, is an economically cheap and ecologically sound technique of pest management.
Considerable progress has been made in developing varieties with acceptable level of
resistance in the case of top borer. Moreover, the best build up can be reduced by
avoiding the cultivation of highly susceptible varieties, for instance Co 8021 for shoot
borer, CoJ 64 for top borer, CoJ 67, Co 740, Co 975, Co 62175, Co 7219, CoA 7602 and
CoR 8001 for scale insect and Co 7704 in areas prone to mealy bug infestation.
3.2 BIOLOGICAL CONTROL
If undisturbed by adverse factors, the large number of parasites, predators and
pathogens occurring in the sugarcane ecosystem provide an effective natural control of
many pests on several occasions. Colonization of specific parasites has resulted in the
effective suppression of few key pests. A notable example is the colonization of Isotima
javensis Roh. in Tamil Nadu and Karnataka for the suppression of top borer (Puttarudriah
and Usman, 1961, Raja Rao, 1964) which virtually eleminated the use of insecticides for
the past 4 decades. Redistribution and mass release of Epiricania melanoleuca Fletcher
has provided effective suppression of pyrilla in several states like Haryana, Uttar
Pradesh, Gujarat, and Maharashtra (Misra and Pawar, 1984). As a result aerial spraying
of toxic insecticides has been avoided in the sub-tropical India, which has resulted in the
saving of more than a crore of rupees every year (Chaudhary and Sharma, 1988).
Inundative release of Trichogramma chilonis Ishii for the control of internode borer in
Tamil Nadu (Sithanantham et al., 1978) is also found to be beneficial. Among the insect
pathogens, granulosis virus is found to be useful in the management of shoot borer and
the milky disease bacterium, Bacillus popilliae and the fungus Beauveria brongniartii are
found promising against white grubs.
3.3. CULTURAL CONTROL
Cultural control is one of the oldest methods of crop protection and these methods
are compatible with most other control measures. Several cultural practices like
149
adjusting time of planting, seed selection, trash mulching, earthing up, detrashing, proper
irrigation and drainage, optimum manuring etc. have been found useful in suppressing
pests like shoot borer, internode borer, stalk borer, mealy bugs, scale insects and white
flies. However, some of the practices may influence other pests favourably. For
example, trash mulching, which reduces shoot borer incidence, may increase the damage
of young shoots by armyworm, termites and rats.
3.4. MECHANICAL CONTROL
Mechanical control is also compatible with other control methods. Spectacular
success has been achieved in the control of Gurdaspur borer by collection and destruction
of infested canes during the gregarious phase (Agarwal, 1980). White grub suppression
has been successful by the timely collection and destruction of adult beetles either
naturally or using light traps. However, adoption of mechanical control measures has to
depend much on the timely availability of labour and cost benefit analysis.
3.5. CHEMICAL CONTROL
The undesirable side effects of insecticides underline the fact that they must be
used judiciously and those that are narrowly selective against target pests must be sought.
Soil application of insecticides and sett treatments does not interfere with natural
enemies. Whorl application is also less disruptive. For instance, soil application of
granules of lindane, chlorpyriphos and sevidol are recommended for the suppression of
shoot borer. All these insecticides are selective and do not harm the activity of its
principal parasite, Sturmiopsis inferens Tns. (Easwaramoorthy et al., 1990). Another
example for selective use of insecticide is in the case of top borer control. In North
India, effective control of top borer is obtained with carbofuran granules applied @ 1 kg
a.i./ha (Avasthy and Banerji, 1982) or phorate granules @ 3 kg a.i./ha during the first
week of July, synchronising with the appearance of the most destructive third brood of
the pest. The chemical application does not affect the parasite, Isotima javensis Roh.
directly and it also helps to reduce the margin between parasite: host ratio, so that the
parasite can effectively check the pest subsequently. Similarly, selective use of
insecticide is possible in the control of scale insect. Soil application of phorate,
carbofuran and quinolphos do not adversely affect the parasite Adelencyrtus mayurai
Subba Rao, while foliar sprays of dimethoate, monocrotophos, quinalphos, carbosulfan
150
etc. reduce the level of parasitism by the parasite under field conditions. Soil application
of insecticides at the time of planting or 30 days after that does not harm the spider fauna.
Some insecticides are less harmful to certain stages of parasites even as foliar
sprays. For instance foliar sprays of malathion (0.5 kg a.i./ha) and dimethoate (0.4 a.i./ha)
are reported to be least harmful for the cocoons of Epiricania melanoleuca F. (Verma and
Bindra, 1980). However, recent observations on the aerial spraying show that the
parasite larvae are adversely affected. The larvae are dislodged from the host body and
fall to the ground and cannot form viable cocoons. It is evident that toxicity depends
upon the developmental stage during which the insecticide applied. Similar results were
obtained in the case of Trichogramma spp. (Sithanantham and Navarajan Paul, 1980).
3.6. OTHER METHODS
Use of synthetic sex attractants promise effective monitoring of stalk borer,
internode borer and shoot borer. These pheromones can also be used in their management
(David et al. 1985). Fluorescent light traps are useful in attracting the beetles of
Holotrichia consanguinea Blanch. They can be used during the beetle emergence season
in areas where the pest is a serious problem. Light traps are also useful against root borer.
SELECTED REFERENCES
David, H., S.Easwaramoorthy and R. Jayanthi (1986). Sugarcane Entomology in
India. Sugarcane Breeding Instt. Publ. Coimbatore. pp. 564.
David, H. and S.Easwaramoorthy (1988). Biocontrol technology for sugarcane pest
management. Sugarcane Breeding Instt. Publ. Coimbatore. pp 378.
151
EXTENSION AND TECHNOLOGICAL PACKAGE FOR SUGARCANE IMPROVEMENT
R.THIAGARAJAN AND RAJULA CHANDRAN
Introduction
Many of the developing countries have achieved outstanding agricultural progress
in the recent years. However, there has been little effect of green revolution technologies
in most of the holdings of the resource - poor farmers. New technologies rarely spread
beyond the large farmers and the aggregate impact remains small (Russel et.al 1989;
Mullen 1989). This lack of progress by resource - poor farmers is a feature of agricultural
development in many countries and it has been argued that it is largely due to its
inappropriateness of the transfer of technology (TOT) approach used in many research
and development programmes. The system of research is usually conducted in a top down
fashion, supported by various formal diagnostic and experimental techniques and often
fails to capture the real priorities and interests of farmers indeed, the research is often
carried out in such a way that it denies attention to the majority of resource - poor
farmers. The conditions under which resource - poor farmers operate are so varied that a
farming systems approach is also inadequate. So, farmers participation in the technology
development is highly essential.
METHODOLOGY
The participatory extension approach has two components namely, participatory
technology development and participatory technology transfer.
PARTICIPATORY TECHNOLOGY DEVELOPMENT (PTD)
In recent years, the agricultural development schemes or projects have
demonstrated that agricultural production can be improved in resource - poor regions
through the adoption of technologies that maximize the use of on-farm resources
provided that farming households themselves are fully involved in the generation of
technologies; in their extension to other farmers and in the experimental adaptation to
local conditions (Bunch 1990, Chambers et al 1989).
152
PARTICIPATORY TECHNOLOGY TRANSFER (PTT)
The heart of the diffusion process is the modeling and imitation by potential
adopters of their near-peers who have previously adopted a new idea. In deciding whether
or not to adopt an innovation, we all depend mainly on the communicated experience of
others much like ourselves who have already adopted. These subjective evaluation of an
innovation mainly flow through interpersonal networks. For this reason, we must
understand the nature of networks if we are to comprehend the diffusion of innovations
fully (Rogers 1983). History reveals that diffusion campaigns are more likely to be
successful if the change agents identify and mobilize opinion leaders. Opinion leadership
is the degree to which an individual is able to influence informally other individuals
attitude or overt behaviour in a desired way with relative frequency. Working through
leaders improves the credibility of the innovation, there by increasing its probability of
adoption. In fact, after the opinion leaders in a social system have adopted an innovation,
it may be impossible to stop its further spread.
The methodology involved the following strategic approaches.
Interaction meetings
Yield gap analysis at macro-level
Selection of a village with high yield gap
Rapid Rural Appraisal (RRA) exercise
Transact analysis
Micro-level survey for constraint analysis
Studying the community protocol
Organizing cane growers clubs
Prioritization
Identification of technologies (including indigenous technical knowledge) for
immediate spread
Farmer-Scientist workshop
Conducting PTD experiments
Farmer to farmer visits
Integration with existing packages
Participatory technology transfer
153
Preparing a working paper
This PTD experiments have to be repeated until the scientific results are packaged
in a form that is ready to be adopted by users. This stage in the technology development
is called commercialization. Perhaps the most crucial decision in the entire technology
development process is the decision to begin diffusing the innovation to potential
adopters.
PROJECT IMPLEMENTATION PROCESS
Participatory technology development: Considering the importance of assessing the
relevance of the PTD approaches under Indian conditions, a collaborative research
project entitled "Use of participatory technology development and indigenous technical
knowledge in sugarcane development programmes" was initiated by Sugarcane Breeding
Institute Coimbatore (Indian Council of Agricultural Research) and Annamalai
University. The project is implemented at the reserved area of the NPKRR Co-operative
Sugar Mills, Mayiladuthurai availing the facilities offered by the factory. The Thiruvali
village in the reserved area of the factory was selected for the study. Based on the field
visit, constraints affecting sugarcane productivity in the village were listed and ranked at
a post-community walk discussion session. For the constraints listed, suggestions for
overcoming the maladies were discussed. The technologies, which were readily available
and well suited to the local conditions, were immediately adopted by the farmers. A few
important constraints for which the technologies already available might not suit to their
local conditions and for which the farmers were willing to conduct experiments to
identify appropriate technologies that would suit their method of sugarcane cultivation
were also identified. In addition, the trialability of the problem, probable solutions
available and the willingness of the farmers were also taken into consideration and the
following topics were chosen for PTD.
i. Selection of varieties for wetland condition
ii. Sandy soil management
iii. Ratoon management
Each experiment had different treatments and observations to be recorded at
various stages of crop growth. For recording each observation, the concerned scientists
demonstrated the method of data collection to the farmers and farmers themselves
154
recorded the necessary observations and also maintained records. Transect analysis was
used as an important tool for initiating the participatory technology development
programme.
PTD Trials
The results obtained from ten trials laid out in the experimental village are
presented below. Farmer - Scientist workshops were conducted in the village where in
results obtained in the PTD trials were discussed.
Trial I: Selection of varieties for wetland conditions
Fourteen pre-release and released sugarcane varieties were tried. The trial supported the
proposal of giving farmers the leading role in on-farm experimentation for testing new
varieties or new crops (Farrington and Martin, 1988).
Variety Cane yield t/ha Variety Cane yield t/ha
Co 8362 122.25 Co 8014 121.75
Co 8371 141.00 Co 8021 162.75
Co 85019 137.00 Co 8122 150.25
Co 85002 148.25 CoG 93076 178.75
Co 86010 148.00 Co 87044 143.0
Co 7704 124.75 Co 87025 140.75
Co 7914 182.75 Co 86032 156.00
Decision
Considering the cane yield obtained from different varieties, morphological
characteristics as observed by the farmers at various stages of crop growth in the trial plot
and also their current status of resistance reaction to red rot disease it was decided that the
farmers in the village would take up planting of CoG 93076, Co 8021 and Co 86010 on a
commercial scale.
155
Trial 2: Sandy soil management
S.No Treatment Cane yield (t/ha)
1 Local practice 111.25
2 Trash mulching at alternate furrows at planting 96.75
3 Application of nitrogen and potassium fertilizer in four
split doses at 30,60,90 and 120 days
112.00
4 Application of additional dose of nitrogen (25% more
nitrogen)
116.00
5 Application of pressmud 106.75
For treatments 2,3,4 and 5 the following practices were followed.
1. Clay application @ 50 tonnes per hectare
2. Application of superphosphate as basal dose
3. Termite control
4. High earthing up
Decision
Realizing the effectiveness of the treatments, the farmers in the village decided
to apply an additional nitrogen dose of 25% to sugarcane crop and also to apply nitrogen
and potassium fertilizers in four split doses.
Trial 3: Ratoon management
S.No Treatment Cane yield (t/ha)
1 Local practice 154.93
2 Gap filling by quartering 144.05
3 Gap filling with polybag seedlings 136.85
4 Local practice + trash mulching 159.75
For treatments 2,3 and 4 the following practices were also adopted.
1. Collection of trash for composting
2. Stubble shaving
3. Off-barring
4. Fertilizer application within 15 days
5. Early irrigation
156
Decision
It was observed that the farmers practice of gap filling, namely uprooting the
sprouts from one corner of the field and planting them in gaps gave better results as
compared to other methods of gap filling. This indigenous technical knowledge could be
popularized in other parts of the State for ensuring better crop stand in the ratoon which is
a pre-requisite for obtaining higher cane yields from the ratoon crop. It was further
decided that the farmers would take up trash mulching also wherever possible.
The observed results were popularised among the farming community. This PTD
approach for identification of technologies, utilization of indigenous technical knowledge
system, indigenous communication systems in the rural societies and the village level
organizations for technology generation and dissemination process was attempted with
the ultimate aim of improving the sugarcane productivity in the area in addition to
bringing about greater awareness among the rural clientele. Cane Grower's Clubs
organized in the study area ensured the sustainability of the efforts taken during the
study. The spread of the technology after the PTD trials was found to be very fast
(instantaneous) which reinstates this mode of transfer of technology for sugarcane
management.
Participatory technology transfer
The project was implemented in the Mill site division of the factory which
included 1165.48 hectares of registered sugarcane area spread over 36 villages. Village
was taken as the primary unit of implementation of the project and two coordinating
farmers were selected from each village. During the year 1995-96 the red rot incidence in
the division was as follows: CoC 90063 - 17.00%, CoSi 86071 - 17.00%, CoC 85061 -
18.00% and CoC 771 - 18.00%.
Through this project, the entire mill site division was covered with red rot tolerant
varieties to bring down the level of red rot incidence as indicated in Table 1.
157
Table 1: Area covered under red rot tolerant varieties in mill site division
Variety Area in hectares Percentage
Co 8021 379.26 32.55
Co 85019 26.74 2.29
Co 86010 18.98 1.63
Co 87025 21.80 1.87
CoC 90063 297.78 25.55
CoC 771 13.18 1.13
CoSi 86071 65.00 5.58
CoSi 95071 169.62 14.55
CoSi 96071 32.08 2.75
CoSi 98071 41.10 3.53
Co 97009 2.10 0.18
CoG 93076 0.64 0.05
Other varieties 97.20 8.34
Besides varietal introduction to bring down the incidence of red rot, efforts were
made to adopt red rot management practices, such as three tier seed nursery programme,
supplying disease free healthy seed material, introduction of red rot resistant varieties,
uprooting and burning of affected clumps, soil drenching with bavistin solution in
affected places and seed treatment with bavistin.
Due to the introduction of red rot tolerant varieties and other red rot management
practices, the red rot incidence was brought down to a minimum level of 0.41%. The
incidence was observed in the varieties CoC 90063 and CoSi 96071. It was decided to
bring down the area under CoSi 96071 and to continue the variety CoC 90063 in which
the secondary spread of the disease was not observed. This methodology was exercised in
the entire sugar factory area.
The results from the experiments indicated that (Table 2) the yield position of the
factory showed 5-10 t/ha increase than the previous years, the red rot incidence was very
minimum (0.23%) when compared with past 4 years and the recovery percent also
showed a slight improvement.
158
Table 2: Varietal percentage, red rot incidence, yield and recovery percent
I Varieties 1995-96 1996-97 1997-98 1998-99 1999-2000
1 CoC 85061 15.00 - - - -
2 CoC92061 3.00 - - - -
3 Co 6304 - - - - -
4 CoC 90063 50.00 33.00 56.00 35.00 33.33
5 CoSi 95071 - - 3.00 29.00 29.84
6 Co 8021 10.00 28.00 18.00 14.00 10.39
7 CoG 93076 - - - - 0.42
8 Co 86249 - - - - 0.43
9 Co 85019 - - - - 0.60
10 Co 87025 - - - - 0.72
11 CoSi 98071 - - - 9.00 5.46
12 CoSi 96071 - - 3.00 - 11.81
13 Co 86011 - - - - 0.86
14 CoSi 86071 15.00 30.00 7.00 - 1.04
15 Co 86010 - - - - 4.71
16 CoC 98071 - - - - 0.39
17 CoC 671 - - - - -
18 CoC771 - - - - -
19 Other varieties 7.00 9.00 13.00 13.00 -
II Red rot
incidence%
25.79 17.84 0.69 0.49 0.23
III Yield t/ha 70.00 67.50 70.00 75.00 82.50
IV Recovery (%) 7.43 8.52 7.93 8.36 8.67
Phase II of the project was implemented in Perur Division of M.R.K. sugar
factory (1600 acre). The project was implemented through 50 opinion leaders (selected
from eight villages) with a farm size of 1-2 acres and the variety Co 86032 was
introduced through them. A training programme on 'sugarcane production technology'
was organized for the selected cane growers.
159
Due to the implementation of the project the variety Co 86032 could occupy a
remarkable area in 2001-2002 planting season. The details are given in Tables 3 and 4.
Table 3: Percentage of plant & ratoon area under different varieties in Perur
division
S.
No
Variety 2000-2001 Season 2001-2002 Season
Area in acres Percentage Area in acres Percentage
Plant Ratoon Plant Ratoon Plant Ratoon Plant Ratoon
1 Coc 90063 277.30 375.50 39.97 51.79 119.00 506.10 11.39 59.09
2 CoSi 95071 3.50 211.00 0.50 29.10 - 19.00 - 2.22
3 Co 86032 190.80 40.00 27.50 5.52 582.25 199.90 55.71 23.34
4 Co 97009 163.00 46.55 23.49 6.42 66.50 83.60 6.36 9.76
5 CoSi 98071 18.00 26.50 2.59 3.65 - 6.00 - 0.70
6 Co 86010 7.00 6.50 1.01 0.89 - 5.50 - 0.64
7 CoC 671 4.50 - 0.65 - 110.05 15.00 10.53 1.75
8 CoC 98061 25.00 5.00 3.60 0.69 20.85 8.45 1.99 0.98
9 Co 86011 3.75 - 0.54 - - - - -
10 Co 86249 1.00 7.00 0.14 0.97 - -- - -
11 Co 8021 - 7.00 - 0.97 - - - -
12 CoV 92102 - - - - 143.50 13.00 13.73 1.52
13 Co 86002 - - - - 3.00 - 0.29 -
Total 693.85 725.05 100.00 100.00 1045.15 856.55 100.00 100.00
The percentage of area under planting for variety Co 86032 has considerably
increased from 27.50 per cent during 2000-2001 planting season to 55.71 per cent during
2001-2002 planting season. The percentage of area under planting for the variety CoC
90063 has drastically reduced from 39.97 per cent during 2000-2001 season to 11.39 per
cent during 2001-2002 season (Table 3).
While considering the total area occupied by plant and raton crop, the variety
Co 86032 occupies the major area of 782.15 acres during 2001-2002 season. Its coverage
was 41.12 per cent during 2001-2002 season, whereas it covered only 16.22 per cent
during 2000-2001 season. The CoC 90063 coverage was maximum of 46.01 per cent
160
during 2000-2001 season but its coverage was 32.87 per cent during 2001-2002 season
mostly constituted by ratoon. (80.96 per cent)
Table 4: Percentage of total area under different varieties in Perur division
No Variety2000-2001 Season 2001-2002 Season
Area in acres Percentage Area in acres Percentage
1 CoC 90063 652.80 46.01 625.10 32.78
2 CoSi 95071 214.50 15.12 19.00 0.99
3 Co 86032 230.80 16.27 782.15 41.14
4 Co 97009 209.55 14.77 150.10 7.90
5 CoSi 98071 44.50 3.14 6.00 0.32
6 Co 86010 13.50 0.95 5.50 0.29
7 CoC 671 4.50 0.32 125.05 6.58
8 CoC 98061 30.00 2.11 29.3 1.54
9 Co 86011 3.75 0.26 - -
10 Co 86249 8.00 0.56 - -
11 Co 8021 7.00 0.49 - -
12 CoV 92102 - - 156.50 8.23
13 Co 86002 - - 3.00 0.16
Total 1418.90 100.00 1901.17 100.00
The yield performance of different varieties in M.R.K.Co-operative Sugar Mills
were assessed and presented in table 5. The variety Co 86032 gave highest yield in plant
crop and ratoon crop. As the Co 86032 variety is a new introduction in this area during
1998-99 season. Hence, there is a wider scope to improve the yield position by
advocating crop and ratoon management practices.
Table 5: Yield performance of different varieties in M.R.K.Co-op. Sugar Mill
Variety Plant crop yield t/ha Ratoon crop yield t/ha
1. CoC 90063 65.0 52.5
2. CoSi 95071 62.5 52.5
3. Co 86032 77.5 67.5
4. Co 97009 75.0 77.5
161
5. CoSi 98071 75.0 57.5
6. Co 86010 75.0 57.5
7. CoC 98061 62.5 66.0
8. Co 86249 60.0 62.5
The selected opinion leaders were given orientation training on sugarcane
production technology. The diffusion network analyzed in the next season (Table 6)
indicated that the opinion leaders contacted cane assistants and cane officers frequently
followed by friends, chief cane officers and neighbours. Since the cane assistants and
cane officers visit farmers fields quite often, they have access to get first hand
information about sugarcane technology. Persons from other villages, agricultural
officers and agricultural assistants were least contacted for getting information on
sugarcane technology.
Table 6: Interpersonal network
Source
Frequency of contactTotal score Rank
Often Occasional Rarely Never
Friends 32.26 58.06 - 9.68 97 III
Relatives 22.58 9.68 58.06 9.68 76 VII
Neighbours 25.81 51.61 - 22.58 87 V
Persons from
other villages
6.45 45.16 - 48.59 65 IX
Agricultural
Officer
6.45 48.39 - 45.16 67 VIII
Agricultural
Assistant
6.45 - 61.29 32.26 56 X
Cane Officer 64.52 19.35 - 16.13 103 II
Cane Assistant 83.87 3.23 - 12.90 111 I
Cane
Development
Officer
38.71 29.03 - 32.26 85 VI
162
Chief Cane
Officer
38.71 29.03 12.90 19.36 89 IV
Analysis of the social factors indicates that the variety Co 86032 could spread
easily in the study area due to the following prime factors: high appreciation by fellow
farmers, better performance in farmers fields, favourable opinion about the performance
of the variety by fellow farmers and family members, and preparedness of the farmers to
adopt the variety.
Table 7 indicated that the farmers discussed frequently about yield performance,
tillering ability, crop duration, number of nodes and spineness of leaves which are
considered to be of prime importance in accepting a new variety for adoption. The least
discussed subject was susceptibility to diseases probably due to the pre-awareness about
the performance of the variety regarding tolerance to major diseases.
Table 7: Attributes discussed about the variety Co 86032
S.NoVarietal attribute
Frequency of conversation Total score
RankOften Occasionally Rarely Never
1 Yield performance
83.87 - - 16.13 109 I
2 Crop duration 70.97 13.23 - 25.80 99 III3 Ratoon
efficiency12.90 51.62 - 35.48 75 IX
4 Additional income
6.45 16.13 - 77.42 47 XV
5 Germination 64.52 3.23 - 32.25 93 V6 Tillering
ability70.97 3.23 3.23 22.57 100 II
7 Number of nodes
70.97 - 3.23 25.81 98 IV
8 Length of internode
64.52 - - 35.48 91 VI
9 Spineness of leaves
64.52 - 6.45 29.03 93 V
10 Easiness in removing dried leaves
61.29 - - 38.71 50 IX
11 Flowering 9.68 - 35.48 54.84 51 XIII12 Girth of the
cane9.68 45.16 -- 45.16 54 XII
13 Height of the 58.06 3.23 - 38.71 91 VI
163
cane14 Hardiness of
the cane54.84 - - 45.16 82 VIII
15 Brittleness of the cane
38.71 12.90 - 48.39 75 IX
16 Bud sprouting 22.58 29.03 - 48.39 70 X17 Stalk pithiness 12.90 29.03 - 58.07 61 XI18 Lodging 54.84 - - 45.16 82 VIII19 Utilization of
plant tops as cattle feed
61.29 - - 38.71 88 VII
20 Susceptibility to disease
12.90 - 3.23 83.87 44 XVI
CONCLUSION
The results obtained, the response observed and the experience gained during the
implementation of the project suggests that the participatory technology development
approach could be used as an important tool in the identification of location specific
technologies. It is expected that if the farmers in developing countries are continuously
exposed to the participatory technology development and transfer approach, the level of
success would improve significantly. This was evident from the higher level of
enthusiasm exhibited by the farmers in the Farmer-Scientist workshops conducted in the
villages. Due to participatory approach, the spread of technology from the farmer-
researcher to other farmers in the social system was also observed to be rapid. To achieve
true participation, putting farmers' priorities first, facilitating their analysis and
supporting their experimentation, requires changes which are personal, professional and
institutional (Pretty,1995).
IMPLICATIONS
The implementation of this approach may call for a reform of national and
regional research, extension and planning to create a dialogue with farming households
with particular emphasis upon sensitive survey techniques to discover indigenous
practices and the promotion of technology generation and adaptation by farmers
themselves. Additional State support may also be required to strengthen the farmer to
farmer extension mechanisms to increase the speed of diffusion. Though PTD has already
been tried in many of the developed and developing countries, this is the first time that a
164
combination of approaches (PTD, PTT, utilization of indigenous technical knowledge
and indigenous communication systems) are tried under Indian situations and the
experience gained in this project would serve as a guide to other scientists, extension
personnel and policy makers in framing the future sugarcane development programmes.
REFERENCES
Arulraj, S & Vasanthakumar, J. (1996), Participatory Technology Development - A
case study, Sugarcane Breeding Institute, Coimbatore Discussion paper, 96/1.
Berlin B., Breedlove, D.E and Raven, P.H. (1966), Folk Taxonomies and Biological
classification, Science, 154 : 273-275.
Bunch, R. (1990), Two Ears of Corn, World Neighbours, Oklahoma Cit.
Chambers, R. Amold Pacey and Lon Ann Thrupp (ed).(1989), Farmer First-Farmer
Innovation and Agricultural Research, Intermediate Technology Publication, London
Conklin, H.C. (1957), Hanunco Agriculture, A Report on an Integral system Shifting
cultivation in the Phillippins, FAO, Rome.
Farrington,J and Martin,A.(1998),Farmer participation in agricultural research :a review
of concepts and practices. ODI Agricultural Administration Unit, Occasional Paper
9, Overseas Development Institute, London.
Mullen, J. (1989), Training and visit system in somalia, contraditions and anomalies,
Journal of International Development, 1:145-67.
Pretty,J.N.(1995), Regenerating agriculture: and alternative strategy for growth, London,
Earthscan.
Rogers M. Everett. (1983), Diffusion of innovation, New York. The Free press.
Russel, D.B., Raymond, L.I Dennis R.G and Ruth K.W .(1989), A critical Review of
Rural Extension Theory and practices, Factory of Agriculture and Rural
Development, University of Western Sydney, Australia.
Annexures
Constraints affecting sugarcane productivity in Thiruvali village
1. Poor level of ratoon management
2. Soil problems especially the sandy texture of the soil and lake of proper land
preparation
3. Non-adoption of basal application of fertilizers
165
4. Heavy incidence of early shoot borer
5. Repeated occurrence of water scarcity
6. Late planting of sugarcane
7. Inappropriate sugarcane variety cultivated in the village
8. High incidence of internode borer
9. Improper weed management
10. High incidence of termites
11. Rat menace
12. Profusely flowering nature of existing sugarcane varieties
13. Heavy lodging
14. Non- adoption of harvesting at ground level
15. Lack of availability of organic manures in sufficient quantity
16. Less adoption of appropriate fertilizer management technologies
17. Less adoption of soil testing
18. Incidence of red rot disease
19. White fly problem
20. Improper water management practices
21. Low level of germination
22. Non-availability of good nursery plot
23. Less adoption of half-earthing up
24. Less adoption of deep ploughing
166
PARTICIPATORY EXTENSION APPROACH FOR
SUGARCANE DEVELOPMENT
R.THIAGARAJAN and RAJULA CHANDRAN
Introduction
The technology has to be viewed as a part of the entire farming system of the farmers
of various strata. The farmers out of necessity adopt a multi-disciplinary holistic approach to
their work and it would seem logical that this should apply also to the process of generation
of relevant technology (Sen, 1990). In addition to the remarkable gains attained, the new
technologies have also been accompanied by a number of serious short and medium term
problems. These include increasing incidence of pests, diseases and weed problems (Nickel,
1973) sometimes aggravated by pesticides use, deterioration in soil structures and fertility
(McNail, 1972), increased indebtedness and inequality (Pearse, 1980).
In transfer of technology process the question is concerned with the mechanism and
organization of technology transfer. Extension personnel have been using a number of
extension teaching methods that include individual, group and mass contact methods,
according to their availability and their own perception on their effectiveness. A number of
experimental studies have already been undertaken by extension scientists in different parts
of the country to identify the effectiveness of individual or combination of two or three
extension methods under different situations. However, under the prevailing situations as
occurring in the socio-economic milieu in the sugar factory areas, the findings of the above
studies may not be directly applicable. Hence a study was undertaken to evolve an integrated
technology transfer package for sugarcane.
TECHNOLOGY PACKAGE
Innovations often are not viewed singularly by individuals. They may be perceived
as an interrelated bundles or complex of new ideas. The adoption of one idea may trigger the
adoption of several others. One approach that seeks to capitalize on this tendency is
'technology package'. A bundle of agricultural innovation, usually including improved crop
varieties, fertilizer and other agricultural chemicals, is recommended in toto to farmers. The
assumption is that the villagers will adopt the package more easily and rapidly than each of
167
the innovation individually. More importantly, by adopting all at once, the farmers get the
total yield effects of all the innovations, plus the interaction effects of each practice on the
others. (Rogers and Shoemaker, 1971). In the last two decades what we have seen, however,
is not the diffusion of specific material items alone (such as seeds or fertilizer), but rather an
increase in deliberate efforts to encourage the adoption of packages of technologies,
technology management practices and many instances, financial and marketing practices as
well.
EXTENSION PACKAGE
If the probability of adoption is to be maximized, communication channels must be
utilized in an ideal time sequence, progressing from mass media to interpersonal channels
(Sill, 1958). A temporal sequence is involved in agricultural communication in that
messages are sent out through media directed to awareness, then to groups and finally to
individuals. A farmer upsetting this sequence in any way prejudices progress at some point
in the adoption process (Copp, 1958). The greatest thrust out from the knowledge function
was provided by mass media, while interpersonal channels were salient in moving
individuals out of the persuasion function. Using communication channel that was
inappropriate to a given function in the innovation decision process was associated with later
adoption of new ideas because such use delayed progress through the process (Rogers &
Shoemaker 1971).
Schramm (1964) pointed out that there are certain tasks which one channel can do
that others cannot do. For these reasons, communication channels often can be combined to
advantage. Mass media and interpersonal channels play complementary roles rather than
competing roles in the transmission of messages and hence, they may be combined in media
forums to yield maximum results.
It is advisable that instead of selecting the various extension methods to be followed
in a specific sugar factory situation on an adhoc basis, it would be ideal if a package is
evolved through scientific experimentation and recommended to sugar factories for
complete adoption.
METHODOLOGY
To implement the extension and technology package the following methodology was
followed.
168
- Selection of a sugar factory zone where the present levels of sugarcane productivity
is low and it would be possible to bring about significant improvements in the
overall sugarcane productivity levels of the area through the systematic
implementation of a well planned cane development programme.
- The area was intensively surveyed by a multidisciplinary team of scientists to
identify the production potential available and the constraints affecting the sugarcane
productivity in the area. Based on a malady-remedy analysis, a cane development
plan was prepared.
- An informal discussion session was organized with scientists, development
personnel and farmers to finalize the strategy, to determine the targets as well as to
identify the appropriate technologies for mass adoption. Annual plans, medium term
plans, as well as long term plans were drafted for implementation.
- Rapid Rural Appraisal methodology was followed to identify the existing knowledge
and adoption levels among the sugarcane growers in the area as well as farm
productivity and the constraints in improving their productivity.
- An intensive Refresher Training course on "Sugarcane Production Technology" was
organized for the benefit of the cane department personnel of the sugar factory.
- Mass media such as radio, newspaper, posters, wall paintings, hoardings, etc. were
used to create awareness among the sugarcane growers on new sugarcane varieties
and other improved technologies.
- Model farms were maintained in the grower's fields in each cane section to
demonstrate the production potential of the existing technologies.
- Intensive teaching programme in the form of village level campaigns were organized
which included conducting of village level exhibitions, group meetings with slide
shows, distribution of leaflets etc.
- The production and projection of video programmes to teach the sugarcane growers
on these technologies were also be attempted.
- Providing skill teaching by arranging appropriate method demonstrations on the
selected new technologies involving skill.
169
- Organizing sugarcane growers forum (Discussion groups) for each village (or cluster
of villages) to create a favourable climate for the spread of technologies through
discussions, exchange of information and community acceptance.
- Institutional and peripatetic training programme were organized at regular intervals
for the benefit of the sugarcane growers of the area.
- Arranging study tours and field visits to create positive conviction about the
improved technologies among the sugarcane growers.
- Adequate incentives and award schemes also were incorporated as a part of the
package.
- Arranging for the supply of inputs through appropriate agencies and ensuring the
availability of the required inputs in time.
- Arranging farm and home visits by the cane development staff and having follow up
visits to clear the doubts and facilitate correct adoption of technologies.
- Process and impact evaluation and cost-benefit analysis would be carried at different
stages of the project implementation.
- Development of a final package based on the experience gained in this case study.
Implementation of the Operational Research Project
The above methodology was implemented in Ambur Co-operative Sugar Mills area in
North Arcot district of Tamil Nadu during the year 1990-91, with the introduction of a location
specific "technology package" by adopting an appropriate "extension package" availing the
infrastructural facilities provided by the sugar factory.
The technological package developed for the factory included:
Improvement in varietal scheduling
Promoting early planting strategy to cover about 25% of the reserved area in October-
November months
Implementation of three-tier seed nursery programme
Pragmatic approach in cane area registration
Seed rate and planting
Fertilizer management
Crop rotation
Weed management
170
Earthing up
Ratoon management
Integrated pest and disease management
Drought management
Management of areas affected by tannery effluent
Cane harvest management
Computerization and Development of infrastructural facilities (Improvement of
irrigation potential, Improvement of roads, transport, agro-service facilities, credit
facilities, Soil and water testing facilities)
The extension package included:
Double your cane yield programme
Model farms
Sugarcane production plans
Result Demonstration
Campaigns
Posters
Orientation training
Use of daily calendars
One-day study tours
Farmers training programmes
Extension pamphlets
Use of audio-visual aids
Video programmes and Wireless system.
Visualizing the impact created by the approach in Ambur Cooperative Sugar mill area, the same
methodology with minor modifications in the technology package was implemented in the
reserved area of Sri Chamundeswari Sugar Mills Ltd. Mandya during 1996-97. Results of the
impact analysis are discussed below.
171
Impact analysis
Ambur Cooperative Sugar Mills LTD. Tamil Nadu
The average cane yield in the sugar factory reserved area increased from 53.05 t/ha in
1990-91 to 78.58 t/ha in 1994-95 indicating an increase by 45.63 percent thus resulting in an
additional income of Rs. 13,986 per hectare.
The sugarcane available for crushing by the sugar factory from its reserved area improved
from 2.06 lakh tonnes in 1990-91 to 5.44 lakh tonnes in 1994-95. Simultaneously the
percentage of own cane crushed by the factory also improved from 45.78 percent in 1990-91 to
100.00 percent in 1992-93 and continued to remain at 100.00 percent in the succeeding years
also.
Sugar factory performance also improved during the project period with respect in the
following aspects. Cane area registered, total cane crushed, % of own cane, crushing duration,
average cane yield, total sugar bagged and reduction in percentage of subsidy on cane transport
to total cane development expenses. However, though the peak season sugar recovery % could
be maintained at a constant level, there was a marginal decrease in overall sugar recovery
percent.
Sri Chamundeswari Sugar Mills Ltd. Mandya
The average cane yield in the sugar factory reserved area increased from 82.5 t/ha to
95.0 t/ha during the project period i.e. from 1996-97 to 1999-2000.
The sugarcane available for crushing by the sugar factory from the reserved area
improved from 5.00 lakh tonnes in 1996-97 to 8.5 lakh tonnes in 1999-2000.
The area under the variety Co 62175 was brought down from 73% in 1996-97 to 28% in
1999-2000. Impressive improvement was seen in sugar recovery percent; it improved from
8.3% in 1996-97 to 10.06% in 1999-2000.
RECOMMENDATION
All the sugar factories in the country may undertake an yield gap analysis in their
respective areas of operation and prepare a cane development plan indicating the specific
technologies to be introduced/diffused in the area. They should take concerted extension efforts
to improve the level of adoption of the technologies and also ensure the availability of the
required infrastructural facilities for bringing about a significant improvement in cane yield
level as well as sugar factory performance.
172
CONCLUSION
The positive and impressive results obtained from the Operational Research Project
being implemented by the Sugarcane Breeding Institute at the Ambur Co-operative Sugar Mills
Ltd. Tamil Nadu and Sri Chamundeswari Sugar Mills Ltd. Karnataka indicated that the
systematic efforts made to introduce a set of location specific technologies using an integrated
technology transfer package along with ensured inputs and other infrastructural facilities leads
to improved sugarcane productivity and sugar factory performance. The methodology adopted
in this study can be implemented in other potential areas by formulating a suitable
technological and extension package.
REFERENCES
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process Rur. Soc. 23 : 146-157.
McNail, M.(1972), Lateritic soils in District Tropical Environments: Southern Sudan and
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609.
Nickel, J.C. (1973), Rest situation in changing Agricultural Systems - a Review, Bulletin of
Entomological society of America, 19: 136-142.
Pearse, A. (1980), Seeds of poverty, seeds of want: Social and Economic implications of green
revolution, Clarendon press: Oxford
Rogers M. Everest and Shoemaker F.E. Loyd. (1971), Communication of Innovations.
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Sen, D. (1990), Poverty alleviation and management of Agricultural Extension, A Critique;
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Shramm, Wilbur.(1964), Massmedia and national Development, Stanford, Cal : Stanford Univ.
press.
Sill, Marice. (1958), Personal, situational and communicational factors associated with farm
practice adoption, Ph.D. thesis, University park: Pensylvania State University.
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COMPUTER APPLICATIONS IN SUGARCANE PRODUCTION
S.SHUNMUGASUNDARAM
A. INFORMATION MANAGEMENT SYSTEMS AND DATABASES
Research and development activities in an area of activity like agriculture
involves decision making which is often beset with uncertainty and risk. This risk can be
minimized only if decisions are based on sound and reliable information on different
aspects. The generation of reliable information however depends on sound statistical
programs for generation of data, their processing and storage on computers as well as
their interpretation and communication to a variety of user agencies. Modern computer
power and improved communication media like Internet have completely revolutionized
our outlook on the role of information in research and development activities. The
generation of information as a production process has assumed the role of a technology,
wherein commodity produced is information which, as a public goods, is an essential
input to the decision making process and therefore has the implications for the design of
information system. The value of this commodity (i.e. information) increases as the
uncertainty or risk in the decision process increases and can therefore act as a powerful
tool in the hands of scientists. The development of information as a technology has
progressed from electronic data processing through information system to knowledge
engineering. From the mere manipulation of large amounts of data, we have come to the
structuring of this data to give information to the user and in future actual deductive
powers and reasoning.
Two new concepts are emerging from information systems. They are data mining
and data warehousing. A data warehouse is a central storage of data that has been
extracted from operational data. The information in a data warehouse is subject oriented,
non-volatile and of historic nature, so data warehouse tend to contain large data sets.
Data mining deals with the discovery of hidden knowledge, unexpected patterns and new
rules from large databases. It is currently regarded as the key element of much more
elaborate process called knowledge Discovery in Databases (KDD). The combination of
data warehousing and data mining and decision support indicates an innovative and
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totally new approach to information management. Until now, information systems have
been built and operated mainly to support the operational processes of an organization.
KDD and data warehousing view the information in an organization in an entirely new
way as a strategic source of opportunity. It is a first step towards realizing information as
a production factor. Viewed in this perspective, no doubt Indian Agricultural Research
System has produced enormous amount of data that could be fully exploited using the
KDD concept.
CREATION OF DATABASES AT SBI
Databases for sugarcane general information, selection of parents and crossings,
germplasm collections and sugar manufacturing reports are available in two sources.
1. MS-ACCESS under Windows environment:
Four volumes on sugarcane germplasm collections viz. S. spontaneum, S.
officinarum, S. barberi, S. robusturm, and Foreign hybrids are available in electronic
media. The details on Co releases of this Institute have also been placed in another
database. Data being received from all sugar mills on their final manufacturing details
are placed in one database file.
Under the LAN system, these packages could be utilized by any user in his
computer node. Both Internet browsing and E-mail facilities could also be availed of
under this LAN environment.
2. GRINS under DOS environment
Genetic Resources Information System (GRINS)
GRINS, an acronym for Genetic Resources Information System is essentially an
application package developed for the creation and management of an information
system for databases on crop genetic resources. The package has been prepared keeping
in mind the needs of crop scientists who are engaged in evaluating a variety of useful
characteristics on genetic material of different crops. It is essentially aimed at Personal
Computer environments.
GRINS can be used for computerizing data collected on germplasm and other
important genetic material of various agricultural crops. For example, we may have
passport information on hundreds of accessions collected and their evaluation data on a
number of morphological and other quantitative characters. GRINS helps in effecively
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organizing all these data in the form of a database system, using which one can query the
database for retrieving list of accessions satisfying a special trait or a combination of
traits; prepare statistical summary reports like frequency tables, correlation matrices, two
way association tables etc.
Another area of application is the management of information generated from
crossing programs, where data on a number of varieties or selection emanating from a
crossing programe are available like genotype name/number, female parent, male parent,
the year of selection, the zone suitable for the variety and character evaluation particulars
on a number of morphological and economic traits.
GRINS HAS THE FOLLOWING FEATURES
The software is standalone and there is no need to depend on other database software
for creation of the required databases and their maintenance
Databases can be created for any crop genetic resources and the program functions
are very general in using the databases, irrespective of the data variables defined by
the user. More than one database, whether they belong to the same crop or different
crops can be maintained under one single program.
User can define look up tables for code reduction in case of passport data fields
Data codes can be checked for their validity vis-a-vis code dictionaries and look up
tables
A powerful and interactive database editor is provided for data entry with on line
code selection
all the outputs can be saved in text files and they can later be compiled for preparing
very comprehensive catalogues or reports.
An interactive query designer for creating and running queries is one of the salient
feature of GRINS. A large number of query expressions can be saved in a single file
and any number of them can be retrieved and run in a batch mode at a later stage.
A variety of statistical summary reports (like frequency tables, two way tables,
analysis of variance, correlation matrices etc.) can be generated.
The data files created using GRINS are compatible with the popular dBase III plus
format and they can be used in programs which can access such files.
On line help and documentation is provided wherever needed.
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The program is divided into various modules and all the modules can be accessed
through interactive menus and sub menus, which are very user friendly.
The program is database driven in the sense that, for a selected database, the menus
will automatically behave as per the database specifications defined at the time of
data initialization.
There is an utility module for performing routine file management activities like
copy, rename, delete, create and remove directories and advanced option like copying
database structures, renaming of database field names etc. from within the program.
B. USE OF COMPUTERS IN DATA PROCESSING AND DATA ANALYSIS
Statistical packages such as SAS, SPSS, SPAR, MICROSTAT and INDOSTAT
have been in usage for processing data being collected from the statistically laid out field
trials. These packages as well as other packages developed through MS EXCELL,
FORTRAN 77, BASIC are extensively utilized by the researchers. The sophisticated
statistical techniques and biometrical methods are widely employed in their research
areas due to easy availability of computers and quick data processing through these
packages.
C. COMPUTER MODELS CURRENTLY IN USAGE
Recent trends in statistical methods that are of immense relevance to agriculture
are (I) crop weather relationships and its use in yield forecast (2) Forecasting of crop
yield based on bio-metrical characters (3) Crop growth simulation models (4) Agro-
meteorological crop yield assessment and development of early warning systems (5) Non
linear statistical models with application to crops, pests and fisheries (6) Forecasting of
outbreak of pests and diseases (7) Time series forecasting (8) Use of Artificial Neural
Networks (9) Resampling techniques and (10) Statistical expert systems.
i. SIMULATION
There are many problems which cannot be adequately represented by a
mathematical model or the solution of the model is not possible by analytical methods.
In such situations simulation is the only resort, though it is an expensive way to arrive at
the solution.
Simulation is a numerical technique for conducting experiments on a digital
computer, which involves certain types of mathematical and logical relationships
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necessary to describe the behaviour and structure of a complex, real world system
extended over period of time.
Simulation is a useful and appropriate management technique, which permits the
testing and evaluation of current system performance or need for real world
experimentation.
The following are the main steps in the method of simulation
i. Design and implementation of the simulation model
ii. Verification of the model
iii. Validation of the model
A validated model is one that has been proved to be a reasonable abstraction of
the real world system, it is intended to represent. This can be done with the half of part
data. A great deal of the responsbility for the validity of the results depends on the skill
with which the model is designed.
A simulation model is a simplified representation of real life situations, which
allows the understanding, and solution of problem to be achieved by a trial and error
approach. A good simulation model should be (I) accuracy (ii) acceptable to the
problems and (iii) quick to generate.
Thus simulation is much more flexible technique which can be applied to a wide
variety of problems. The only problem is that it is quite time consuming and expensive
few e.g. of simulation problems in sugarcane are detailed as under:
1. USE OF COMPUTERS IN LAND LEVELLING, LAND VALUATION AND
FARMING OPERATIONS
Computers have been accused by their critics and some humourists of everything
from debiting a toothbrush purchase with $1 000 000 to assigning a fibre of 270.01 to
wellgrown plant cane. But agriculture is making increasing use of their speed and
intricate calculation ability. Whether to improve block drainage or to assist irrigation
application, the practice of land levelling is an important feature of efficient farming.
Level pattern, soil type and situation, range of slope which will provide adequate
drainage without risking erosion can be assessed through computers. Provided the cost
of earth moving is known, the computer can give an estimate of the cost of the work, an
accurate calculation of the amount of soil to be moved or filled in at each point in the
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block. This is achieved by entering minimum and maximum acceptable grades, the
anticipated ratio between cutting and filling, plus numerical data including number and
spacing of levelling points as well as actual readings obtained. Sugarcane operations are
complex agricultural investiments. The decision on whether or not to buy acreage of land
requires an assessment of several forces, which may change in the future. The
presentation offers a flexible procedure for estimating the effect of such parameters as
appreciation in land values, changes in the expected income from future sugar yields, the
level of desired rates of return on investment, mortgage credit terms and income tax
levels on the amount that can be paid for acreage. Providing computer to a grower can be
one of the most important and frightening steps towards improving farm management. A
computer may be sought to enhance the children’s education, to provide some well
earned leisure or for keeping records of farming practices and productivity. It might help
with decision-making and keeping track of farming operations. A computer programme
is a tool to access farming information and it enables a grower to make informed business
decisions based on past results. It also saves a great deal of time and wary. In Australia,
a computer programme has been designed by a farmer specifically to still his farm and
their needs. The program name as CANEPLAN ties all areas of the farming enterprise
together, paddock work, equipment maintenance, sheds, headlands and houses, plots
rainfall and tree care. The land working informations is sorted by block number,
enabling the grower to see exactly what has been done to a block over the years and the
results. Also this program answers to questions like when and where was a variety
planted in a year and by whom over how much of area of land. CANEPLAN is a
WINDOWS based programme. It requires a 386 or 486 computer.
Growers could also be advised to purchase a MODEM and a phone in the long
run in order to take advantage of any free trail offers for connecting to the INTERNET.
There is an enormous amount of information available to farmers in this media. Weather
maps can be obtained faster from the meteorological departments. CANEGROWER’s
homepage is obtained via the Farmwide Internet site at http:\\www.farmwide.com.us.
Another computer program “CANEMAN" designed by the bureau of sugar
experiment station, Australia provides graphs to compare productivity between blocks or
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varieties, clearer reports, easier data entry and recording of soil test results. Again the
sugar industry in Australia is now able to assess rainfall variability data using a computer
database package designed by scientists at CSIRO tropical agriculture in Brisbane. This
helps the grower in rainrisk. Potential applications of the Rainrisk Database system are
to assess the requirements for irrigation and drainage and the wet weather risk to
harvesting operations. The package is easy to use with the operator selecting the
location, the relevant rainfall variable and the time period i.e. from one week to a whole
year. The package calculates cumulative probabilities in tabular and graphical form.
This can be used to assess the risk of rainfall. Risk refers to the probability that can be
estimated from prior information. The amount of rainfall in specific years over a
specified period can also be viewed. This programme again runs in WINDOWS.
2. AUTOMATION OF CANE TESTING, CANE PAYMENT AND CANE
FEEDING
Three basic elements common to all modern systems are viz. 1. Cane weighing
and quality assessment 2. Methods and formulae for calculation of sugar or recoverable
sugar or absolute juice and 3. Cane pricing formulae. In South Africa, the Sugar
Industry Central Board computrized the cane testing service by way of installing a
minicomputer to caputure data directly from weighbridges and labouratory instruments,
thereby reducing labour requirements and possible errors in the manual procedures. The
interface hardware designed and developed to overcome problems caused by the factory
environment and to cut costs were described (King and Evans. 1979).
It is recognized that a well-designed cane payment system is of great benefit to an
industry, provided, and provided it solves many technical, economic at and even social
requirements. Nolting (1981) had described such an automation of cane payment system
being introduced in Brazil. Beginning in the 1950s, direct cane analysis became popular.
The author had hence, introduced the automation of analytical procedures. As the
expressed juice is analysed for Pol, Brix and absolute juice, while the fibre content is
determined from the weight of the press cake, data collection and data processing were
also automated apart from automating the cane payment systems.
The operation of the cane crushing mills of a sugar factory is directly related to
the characteristics of the cane feed and the flow of imbibition water. In Cuba, raw
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materials are harvested in different ways and are received at sugar mills from different
areas and in different means of transport. The combination of these factors results in
erratic feeding of them in mills. It has been demonstrated that the operation of the mills
is more efficient when the cane, feed is made uniform by making use of statistical
principles and automating of cane feeding. Dynamic programming, another statistical
technique, is completely different from linear programming, its advantages being that
non-linear relationship present no problems. it had been found useful for determination
of variables in the optimization of the cane crushing program at South African sugar
mills. it was shown how within any given constraints on throughput rates, cane
availability and starting and finishing dates and month by month crushing rates.
Expected monthly values of process variables and time utilization, the drop in overall
recovery as a result of increased throughput, and the various types of costs were taken
into account. The output included monthly performances, efficiencies and costs as well
as the final maximum profit for the season.
1. CANE TRANSPORTATION SYSTEM
Use of automated cane truck handling system is familiar to the Australian sugar
industry. The nature of the sugar crushing process demands that the automatic handling
system provide high production, inlcuding extreme reliability to reduce plant downtime.
Electricity, controls should be sophisticated enough to proide such feature as “first in first
out” call queuing together with ability to count or time without restriction. They should
be modular in construction in order to simplify maintenance problems. Considering these
points, a programmable controller to a cane truck handling system at Pleystowe sugar
mill in Australia was introduced as early as in 1977. Computer simulation model (CSM)
of a sugarcane transportation system had also been visualised in another country. It was
devised to test alternative strategies and decisions in cane transportation from field to
factory, taking into account weather, equipment failure and capacities, distance of travel,
queuing service and unloading times; manual cutting and loading of the cane was
assumed. Comparison of a computer run with actual operations was also made. A
computer simulation model was also developed in the Philippines capable of testing
alternatives, strategies and decisions in sugarcane transportation management for
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harvesting to the transloading in the mill. This model considered the weather, travel
times, equipment capacity and equipment breakdown.
4. CROP GROWTH STUDIES
Crop growth is a very complex phenomenon and a product of a series of
complicated interactions of soil, plant and weather-models that deal with crop growth,
simulation, they can be distinguished into two categories:
1. Descriptive
2. Explanatory
Explanatory models are means by which knowledge about systems and their
performance is made portable and accessible to users whoch livelihood and welfare
depend on the systems performance. Models are extremely useful because the critical
environmental problems caused by agricultural practices are system problems not
disciplinary ones. Their solutions demand a multidisciplinary approach linking basic and
applied sciences.
A good number of researchers have been actively involved in the development
and building up of crop growth simulation models all over the world but most of these
models are never fully tested or validated over a wide range of conditions restricting their
use. The applicability of a model lies in it being globally tested which would allow the
imperfections and weaknesses of the model to be exposed leading to its refinement.
Two projects can be cited as examples, which have followed this approach by
establishing a network to evaluate crop models.
1. IBSNAT (International benchmark sites Network for Agrotechnology Transfer)
eg. Crop models are CERES WHEAT, CERES RICE etc. CERES - Crop Environment
Resource Evaluation through Synthesis.
2. SARP- Simulation and systems Analysis for Rice Production (initially for rice but has
now diversified to other crops vital to that region)
The First project is based at Honululu, Hawaii while the second one is in
Wageningen, The Netherlands. The ultimate objective is to have a Decision support
system which is essentially a computer software to match crop requirements to the
physical characteristics of the land using a database management system, a set of
validated crop models to simulate genotype x environment x management interactions
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and application programmes to simulate experiments to ascertain the uncertainty
associated with the proposed strategies.
ii. OTHER MODELS FOR AGRICULTURAL APPLICATIONS
The spatially valuable and dynamic agriculture system has attracted many
researchers due to the fact that the system supports our society by providing basic needs
and row material to many industries. GIS (Geographical Information Systems) has made
the handling of spatial variability of the agricultural system easy so much so that new
aspects such as integration of expert system and decision support systems are being
added to many models that are being handled or developed. Before GIS were developed,
researchers have used other techniques to tackle this spatial variability. Some of those
spatial and non-spatial models are listed as below:
FARMSYS: An object oriented filed operations simulator model coupled with an
intelligent information manager.
BEANGRO: A day bean growth simulation model that simulates yield and irrigation
requirements for a variety of management practice, soil and weather combination.
TOMGRO: A tomato plant growth model designed to respond to dynamically changing
temperature, solar radiation and Co2 concentration inside the greenhouse.
AEGIS: Agricutural and Environmental GIS linked to DSSAT (Decision support system
for Agrotechnology Transfer)
IDM: Interactive dairy model, a GIS based interactive under quality simulation model
for dairy operations.
These techniques are now recognized as essential components of modern
agricultural research. Nevertheless, they need enormous amount of data collection for
testing and validation of models and are highly computer oriented. Enormous amount of
work has been done both in India and abroad with regard to conventional forecasting
models like crop weather models, time series models and agro-meteorological crop yield
assessment. Nevertheless, agricultural scientists in India are yet to fully exploit the
potentials of crop growth simulation models and pest disease epidemic models though
there are several reports that they are being extensively used abroad.
Research on application of artificial neural network in forecasting which is of
recent development is yet to reach our R&D laboratories. The artificial neural networks
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have been reported to be effective as computational processors for various tasks including
pattern recognition, classification, data compression, modeling and forecasting.
PACKAGE OF PRACTICES FOR INCREASING SUGARCANE PRODUCTION
RAJULA CHANDRAN and R.THIAGARAJAN
Sugarcane cultivation has spread over a large part of the world covering 350 north
and 350 south of Equator. India, which is the centre of origin of Saccharum species, offers
the most favourable environment for maximum growth and sugar accumulation in the
sugarcane crop. The progress made in the sugarcane scenario in the country since
independence is well recognized and appreciated. Production of sugarcane in India has
been rising gradually during the last three decades. During the base year of the First Five
Year Plan, 1950-51, production of sugarcane was 54.8 million tons from an area of 1.7
million hectares. The current sugarcane production level is 299.22 million tons from an
area of 4.20 million hectares with a productivity of 70.8 t/ha.
Of the two major sugar crops viz., sugarcane and sugarbeet, about 62% of the
world sugar production is achieved through sugarcane while sugarbeet contributes for
around 38%. However, there is every scope to enhance cane production through the
introduction of sugarcane crop in newer and more productive areas of the world.
Cost of production analysis of sugarcane indicates that the fixed working cost
amounts to 68.4 per cent while the variable working cost amounts to 31.6 per cent at an
average yield level of 110 t/ha. However, when the yield per hectare drops, the
percentage of fixed working cost increases as expenditure on these items are incurred
irrespective of production. This will definitely reduce the profit margin among farmers
producing cane at different yield levels. Hence it is imperative to have a greater stress on
the increased productivity at a lesser cost of production in sugarcane. New technologies
identified at different sugarcane research institutions on sugarcane varieties, cultivation
practices and pest and disease management offers scope to enhance cane production. A
few strategies that can be easily followed to achieve these objectives are listed below.
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VARIETY
Varietal evolution is a continuos program and new varieties emerge from time to
time to meet the demand of the sugar industry. Varieties viz., Co 8208, Co 85019, Co
86032, Co 86010, Co 86249, Co 87023, Co 87025, Co 87044, Co 87263, Co 87268 and
CoPant 84211 are found to be promising. The varietal flow coupled with improved crop
management systems, specific to the varieties helps to sustain and improve the sugar
production in the country.
SOIL
Although sugarcane needs a well drained loamy soil with neutral soil reaction for
its ideal growth, it is grown in widely varying soil environments. Soil organic matter is
considered as an elixir of soil productivity. Soil organic matter content can be improved
and maintained by liberal application of green manure, green leaf manure, farm yard
manure, compost and bulky organic crop residues. Pressmud obtained from sugar factory,
sugarcane trash, straw husk, coir pith waste, vegetable or fruit peeling etc. can be
properly composted/enriched and used as manure.
SPACING
The inter plant and intra plant competition determines the spacing leading to
ultimate stalk population. Maximum cane yield can be obtained by proper spacing
between rows. Increasing seed rate without altering row spacing was found to be of little
consequence. On the other hand, increasing density of planting through narrower spacing
proved to be superior and holds promise of enhancing stalk population. This is mainly
due to lesser competition for soil moisture within row. Hence, a closer spacing with
moderate plant population within rows would benefit economic utilization of water which
is high near the furrows.
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SEED RATE
Use of optimum quantity of good quality seed material is essential. It is now
recommended that 1,50,000 buds/ha is optimum as increased rate beyond this level has
produced no special advantage. As a matter of fact, a lower seed rate may be sufficient
provided the material is good, taken from short crop fields.
PLANTING MATERIAL
Planting material should be taken preferably from exclusive commercial nursery
crop raised from primary heat-treated seed material. Otherwise top one third to two third
portion of a mature crop can be used.
SETT TREATMENT
In areas where drought is a common feature in the formative phase, soaking of
the seed material in saturated lime water can be followed. For this, the setts are to be
soaked in saturated lime water (prepared by dissolving 80 kg kiln lime in 400 litres of
water) for one hour prior to planting. This practice induces hardiness and helps in
development of better root system.
After seed selection, chemical treatment of the setts is given to protect the cut
ends from invasion of soil borne pathogens like pine apple disease, wilt etc. and to
remove surface borne infections. Organo-mercurial compounds at 0.25% or carbendazim
at 0.1% as a sett dip for 10 minutes is recommended. A combination of hot water
treatment (500 C for 2 hours ) and fungicidal treatment (Bayleton 0.1%) has been found
to be effective in the control of sett borne infections of smut.
METHOD OF PLANTING
The choice of the method of planting is guided by the soil contour, availability of
irrigation or sub-soil water and soil drainage. In general, planting is done in furrows
opened by bullock or tractor drawn ridger with a depth of 15 to 30 cm, respectively. The
extent of cover provided over the setts in the furrows varies from 50 per cent of the depth
(deep furrow), if it is also intended to be used as irrigation channel, to full cover by
planking as in flat planting. The gradient of the furrow and its length is regulated so as to
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avoid surface loss of irrigation water. With subsequent earthing up, the furrows are
turned into ridges and the former ridges are reduced to furrows serving as drainage
channels during monsoon.
WEED MANAGEMENT
Wider spacing between rows and frequent irrigation favour the growth of
competitive weeds causing shade effect at lower nodal portions of the cane affecting
tillering as well as early growth resulting in low yields. The problem of weeds is serious
in the ratoon crop of sugarcane also. A wide range of experimentation has indicated that
for a sole crop of sugarcane, atrazine is the most effective herbicide, the dosage ranging
from 1.0 to 2.5 kg a.i/ha. It controls most of the seed germinated dicot weeds and grasses
but not vegetatively propagated weeds particularly Cynodon and Cyperus. Under
intercropping situations, atrazine cannot be used. Herbicides that will not harm both
sugarcane and the intercrop, at the same time give satisfactory weed control need to be
used. Alachlor and linuron have been found to be useful for situations like intercropping
of pulses, oilseeds and potato in sugarcane. Several factors like chemical composition,
time of application, method of application, concentration, rate of absorption by plants and
plant efficiency are to be considered in selecting a proper herbicide for maximum
efficiency.
EARTHING UP
Hilling the clumps in stages is required to provide habitat to the roots and with
sufficient height of the soil is achieved, to suppress formation of late water shoots.
Earthing up changes the furrows into ridges and previous ridges into furrows which
automatically permit drainage of excess water during rains besides serving as irrigation
channels. Initial earthing up is light and may be completed in three to four months but
final earthing up is heavy and should be completed before the onset of monsoons.
FERTILIZER APPLICATION
Fertilizer response varies with varieties and environmental conditions. To obtain
the optimum yield and quality, always we have to think of supplying all the nutrients in a
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balanced manner. Studies have indicated that a ratio of 3:1:2 as optimum for sugarcane.
But in many cane areas, phosphorus and potassium are not applied in the quantities
required for optimizing yield and quality while nitrogen is invariably applied at times in
excess which results in poor juice quality and causes lodging. This is because of the
visible effect of nitrogen on sugarcane growth and yield while that of phosphorus and
potassium is not as much visible though their role in the crop is unquestionable.
In sandy soils the loss of fertilizers is more, with the result, for maximum
production, more fertilizer is to be applied leading to increased cost of cultivation. Hence
a judicial management practice is to be adopted for increased fertilizer use efficiency.
They can be grouped as i. Economic dose of fertilizer application in relation to
requirements ii. Balanced fertilizer application iii. Reducing fertilizer loss and increasing
fertilizer use efficiency and iv. Use of organic supplemental source - biofertilizers.
BIOFERTILIZERS
Biofertilizers are preparations containing living cells or latent cells of micro-
organisms, which when used on seed or to soil, fix substantial quantities of atmospheric
nitrogen in the soil. Biofertilizers or bacterial cultures are essentially a supplemental
source of organic nitrogen to inorganic fertilizers. In well drained clay soils, where
moisture is not a limiting factor, Azospirillum is better. In semi-dry loamy and sandy
soils, Azotobacter is a better source.
The cultures are available in peat based inoculation packets. About 5 kg are
needed for covering one hectare. This can be applied in two split doses at 30 and 60 days
after planting. For uniform spread, the culture can be mixed with about 500 kg of
powdered farm yard manure and applied along the base of the clumps. The bacteria
multiply rapidly under optimum moisture conditions. Hence, crop should be irrigated
properly after each application. The culture can be normally stored at 30-320C for about
two months after which the bacterial load reduces.
Trials indicated that there could be a saving of 25 per cent (55-70 kg N/ha)
inorganic nitrogen. Hence, in fertile soils, it is enough if 180 kg N/ha is applied along
with biofertilizers. In sandy and sandy loam soils, 220 kg of inorganic nitrogen with
biofertilizers may be needed. In addition to saving of inorganic nitrogen, the cane yield is
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increased by about 10 tons/ha. As such, there can be an increased net return of about
Rs.6000 per ha.
TRASHING
As the cane grows, the lower leaves gradually dry up. The dried leaves are called
trash. The operation of removing loosely adhering dried and drying cane leaves from the
cane is known as trashing. This is recommended to be done twice, the first at 5 th month
and the second at 7th month. 10-15 tons of trash is being produced from one hectare of
sugarcane field yielding 100 tons of cane.
PROPPING
Sugarcane grown in fertile soils tends to lodge when it is in the fag end of the
grand growth phase or in the maturity phase and when the monsoon is active. To prevent
lodging at this stage, single cane rows are tied by trash twisting. This operation
(propping) is certainly beneficial in areas where cyclonic storm and active monsoon are
prevalent when the sugarcane is in the fag end of grand growth phase or in maturity
phase.
REMOVAL OF WATER SHOOTS AND LATE TILLERS
When the sugarcane crop is in the grand growth phase, some shoots are produced
randomly which grow fast and produce very thick cane. These are called water shoots. As
their growth duration is very short, they contain less sucrose but have more amount of
reducing sugars. After the crop has passed the grand growth phase, tillers are produced in
clumps that are along the field borders and irrigation channels and in places where
sunlight reaches the ground. These are called late tillers. To some extent, they draw the
nutrients from the fully developed cane in the clump and thereby reduce their quality.
These late formed tillers produce cane having 4-5 internodes by the time of harvest. They
also contain more amount of reducing sugars. When the water shoots and late formed
tillers are taken along with matured cane and crushed, the quality of the juice extracted is
impaired. The recovery of sugar or jaggery, as the case may be, will be low from such
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juice. Therefore, the water shoots and late formed tillers are to be removed before they
form into cane. These can be used as valuable fodder for livestock.
IRRIGATION
Depending on the yield level of the sugarcane crop and climatic conditions
prevailing in different parts of the country, the water requirements vary considerably
from 1200 to 3000 mm. For sugarcane, it is necessary to maintain the moisture content
of the root zone soil close to field capacity in the available range. As the active root
system of sugarcane extends up to 50 cm depth of soil, irrigation will have to be given to
bring the soil moisture back to field capacity in the entire top 50 cm soil layer. Sandy
soils require less water while clayey soils require more water per irrigation. But depletion
of soil moisture is fast in sandy soils while it is slow in clayey soil. Hence in sandy soils,
irrigation is to be given more frequently compared to clayey soils.
The following irrigation schedule can be adopted based on the critical stage
concept.
Stage of the crop Interval between irrigations
Germination (upto 35 days) 7 days
Tillering (36 to 100 days) 10 days
Grand growth (101 to 270 days) 7 days
Maturity (271 days onwards) 15 days
PEST MANAGEMENT
The sugarcane crop in India is ravaged by about 212 insect pests and 76 non-
insect pests. These reduce the sugarcane yield by about 20 per cent and also sometimes
drastically bring down the recovery in factories and also affect jaggery production by
reducing its quality as it happens during epidemics of Pyrilla and scale insects. The long
duration of the crop extending to 10-14 months as a plant crop, followed by one or two
ratoons, staggered planting to suit long duration crushing in sugar factories and extensive
cultivation of only a few varieties which may sometimes be susceptible for some pests
over large areas make it ideal for high build up of some of the pests. Moreover, in this
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crop, the application of insecticides is very limited, i.e less than 3% of insecticides used
in India, partly because of the stability of pest population maintained through natural
control by number of natural enemies present in the sugarcane fields and also because of
difficulties in application of insecticides in grown up crop. In order to increase sugarcane
productivity to commensurate with the increased demand of sweetening agents in the
coming years, it is highly essential to increase the average production of sugarcane and
this can be partly achieved through effective integrated pest management.
In integrated pest management, the pests are managed to remain below economic
injury level by adoption of available technologies in a compatible and economic manner
as possible, taking into consideration the ecological, economic and social acceptance. In
order to practice IPM, it is necessary to have clear idea about the key pests in a particular
area, their biology, a sound knowledge of the management techniques available and also
the means to monitor the pest activity by ecological and applied management practices.
The most productive strategy is to maximize natural control forces and supplement the
same with suitable unified management practices for the locally prevalent key pests,
taking into consideration the economics of the control, the benefits accruing and the
compatibility of the treatments, hazards and the adverse effects likely to follow.
DISEASES MANAGEMENT
A conservative estimate of losses due to disease on the total sugarcane produced
ranges from 10 -15 per cent in endemic conditions. The sett transmittable disease cause
maximum damage to crop both in terms of yield and juice quality. Important diseases
transmitted through cuttings or vegetatively propagated material are red rot, smut, wilt,
grassy shoot disease, ratoon stunting disease and mosaic. Hence use of pathogen free
propagating material is very necessary in sugarcane cultivation which takes care of all
serious diseases. Setts should be selected from healthy plots by proper surveillance and
phytosanitary practices. Any new variety for cultivation should be taken only by
obtaining inspected/certified setts from authorized and reliable sources. When the
varieties under cultivation are not altogether resistant, adoption of good cultural practices
play a vital role in reducing disease incidence. A good tillage of the soil also helps to
remove the disease harbouring plant debris and stubbles. In an integrated disease
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management, it may be mentioned that the practices like proper cultural practices,
preparatory cultivation, deep ploughing, proper irrigation and drainage, crop rotation and
heat treated nursery program are important and they should be integrated and super
imposed on a resistant or tolerant variety to realize the maximum advantage to offset the
losses due to diseases.
CANE HARVESTING
Harvesting is to be done only after the crop attains the desired maturity level.
Since the bottom internodes are rich in sucrose, it is essential to harvest the cane 2-3 cm
below ground level. By this, the length and weight of every millable cane can be
increased by 2 to 3 cm and 20 to 30 g respectively. The additional yield may be about 2
to 3 tons/ha. This will also help in better ratooning. Late water shoots are to be avoided as
they add to the weight only and contain very little sucrose. Further, the trash and binding
materials are to be removed and clean cane is to supplied. For every 1% trash and binding
materials, about 0.2-0.4 units drop in recovery will occur since they add only fibre and
ash and reabsorb some of the juice.
Sugarcane harvesting has to be staggered and prolonged to ensure continuous
supply to the sugar factories. The crushing season normally extends from December to
March in most of the areas but sometimes may extend throughout the year with special
season planting. For a large part of the harvesting season, planting season also overlaps.
A careful scheduling of harvest based on the season, crop duration, date of planting and
varieties is essential.
REFERENCES
Alexander, K.C., S.Arulraj.1995. Sugarcane Production Manual. Sugarcane Breeding
Institute, Coimbatore. Pp.129.
Sundara,B.1998. Sugarcane cultivation. Vikas Publishing House. Pp. 302.
ICAR.1987.Technologies for better crops. Sugarcane : package of practices for
increasing production. Allied publishers Pvt. Ltd., New Delhi.
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