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TRANSCRIPT
Geffry Ujie Anak Joshua
Master of Science
(Agronomy)
2013
Faculty of Resource Science and Technology
SEED QUALITY AND LONGEVITY DURING STORAGE OF FOUR
JATROPHA CURCAS L. ACCESSIONS FOUND IN SARAWAK
I
ACKNOWLEDGEMENTS
Praise the Almighty God, my Lord Jesus Christ and Holy Spirit for it was by His divine
grace and mercy alone that knowledge was perceived. I wish to express my utmost
gratitude and heartfelt appreciation to my major supervisor, Associate Professor Dr. Petrus
Bulan for his dedicated supervision, guidance, concerns, assistance, supports, comments
and friendship in the execution and completion of this study. I would also wish to express
my sincere gratitude to my co-supervisor, Dr. Siti Rubiah Bt Zainudin for her guidance and
encouragement throughout the study. My honest thanks and gratitude extended to the
Faculty of Resource Science and Technology for providing the facilities for this study and
the Centre for Graduate Studies for awarding me a full scholarship of UNIMAS
Postgraduate Zamalah. I also would like to express my thankfulness to the farmers (Mrs.
Gunang Ak Agot, Mr. Jonathan Ak Tinggi, Mr. Majing Ak Rimbau and Mr. Tapa Ak
Santap) for their generous assistance and co-operation to permit me to collect samples
from their farms. My deepest gratitude and heartfelt gratefulness also go to my beloved
parents, Mr. Joshua Ak Jalak and Mrs. Ulat Ak Dobi for their great supports, prayer, love
and cares, and unequivocal sacrifices to ascertain better life and education for me. I am
sincerely indebted and earnest thankful to my beloved wife, Mrs. Nancy Ak Majing for her
tremendous love, endless encouragement and assistance, intuition, trust, prayer and cares
which are the strength for me to move on and enable me to accomplish this study and
dissertation successfully. Lastly, my sincere appreciation also goes to my other family
members including my sisters, parents-in-law, brothers-in-laws and my cousin, Mr. Eder
Ak Dari (scholarship guarantor), for their moral support, understanding, prayer, generosity
and trust which gave me strength to complete my master’s degree study successfully.
II
DECLARATION
I hereby, declare that no portion of the work referred to in this thesis has been submitted in
support of an application for another degree of qualification of this to any other university
or institution of higher learning.
......................................................... .........................................................
Date (GEFFRY UJIE ANAK JOSHUA)
Student no.: 09021462
14 October 2013
III
TABLE OF CONTENTS
Page
ACKNOWLEDGEMENTS I
DECLARATION II
TABLE OF CONTENT III
LIST OF ABBREVIATIONS VIII
LIST OF TABLES XI
LIST OF FIGURES XIII
ABSTRACT / ABSTRAK XV
INTRODUCTION 1
LITERATURE REVIEW 6
Jatropha curcas L. 6
J. curcas oil 9
Orthodox and recalcitrant seeds 10
Storage of seeds 11
Seed moisture content 13
Seed germination 15
Seed viability and vigor 17
Seedling vigor 18
Soil chemical properties and texture 19
Plant nutrient 20
Seed deterioration during storage 21
Seed maturation 23
IV
MATERIALS AND METHODS 26
Materials 26
J. curcas seeds 26
Silica gel desiccation 26
Solution of 2, 3, 5-Triphenyl Tetrazolium Chloride (C19H15CIN4) 26
Transparent ziplock and conventional polyethylene bag and sealed plastic
container
28
Germination tray 28
River sand 28
Ethanol solution (70% v/v) 28
Fungicide solution (0.2 % w/v) 29
Paper envelope 29
Aluminum foil 29
Soil auger 29
Methods 29
Seed treatment 29
Initial evaluation 30
Preliminary test 30
Seed moisture content test 30
Viability (tetrazolium) test 31
Live seed (stained embryo) 32
Analyses of live seeds 32
Standard germination test 35
V
Seedling vigor classification test (SVC) 35
Seedling growth rate test (SGR) 36
Biomass of normal seedling 37
Determination of seed oil content 38
Soil and plant nutrient analysis 38
Soil analysis 38
Plant nutrient analysis 39
Data analysis 39
RESULTS AND DISCUSSION 40
Study 1: Initial Assessment of Fresh Seed Lots 40
Seed quality of fresh seeds 40
Moisture content and standard germination 40
Seed viability 44
Live seed 44
Analyses of live seeds 46
Seedling vigor 48
Seedling growth and biomass allocation 50
Discussion 54
Study 2: Seed Quality at Post-storage 62
Quality of seed at post-storage 62
Seeds weight loss 62
Seed deterioration 66
Fungi 67
VI
Flaccid kernel 68
Shriveled kernel 69
Discussion 71
Study 3: Post-Storage 77
Post-storage seeds quality 77
Moisture content 77
Moisture content for 30 days stored seed lots 77
Moisture content for 60 days stored seed lots 77
Moisture content for 90 days stored seed lots 78
Seed germination 81
Germination for 30 days stored seed lots 81
Germination for 60 days stored seed lots 81
Germination for 90 days stored seed lots 81
Seed viability 85
Viability of 30 days stored seed lots 85
Viability of 60 days stored seed lots 85
Viability of 90 days stored seed lots 85
Analyses of viable seeds 89
Seed lots stored for 30 days 89
Seed lots stored for 60 days 90
Seed lots stored for 90 days 90
Seedling morphogenesis 97
Seedling vigor 97
VII
Strong seedling 101
Weak seedling 101
Abnormal seedling 105
Dead seedling 107
Anomalous emergence of seedling 108
Seedling growth 110
Seedling biomass allocation 114
Discussion 118
Study 4: Agrobiology and Seed Oil Content 125
Ecology of studied sites 125
Seed oil content, analysis of soil and plant nutrient 128
Discussion 131
CONCLUSIONS 133
REFERENCES 135
APPENDIXES 144
VIII
LIST OF ABBREVIATIONS
Abbreviation Terminology
Ac Accession
ABA Abscisic acid
CEC Cation Exchange Capacity
CSMC Critical Seed Moisture Content
CKs Cytokinins
CPO Crude Palm Oil
Dp Desiccation period
G Germination
GAs Gibberellins
G-0 Standard germination test for undesiccated seed lot
G-24 Standard germination test for 24 hours desiccated seed lot
G-96 Standard germination test for 96 hours desiccated seed lot
G-168 Standard germination test for 168 hours desiccated seed lot
IAA Indoleacetic Acid
LEA Late embryogenesis abundant
IX
Mt Maturity
M0 Maturity 0
(selective ratio 1:1:1 combination of seed from M1, M2 and M3)
M1 Maturity 1
M2 Maturity 2
M3 Maturity 3
mg milligram
RH Relative Humidity
SD Storage and desiccation
SMC Seed Moisture Content
SMCL Seed Moisture Content Loss
SMC-0 Seed moisture content test for undesiccated seed lot
SMC-24 Seed moisture content test for 24 hours desiccated seed lot
SMC-96 Seed moisture content test for 96 hours desiccated seed lot
SMC-168 Seed moisture content test for 168 hours desiccated seed lot
SVC Seedling Vigor Classification
SVC_Ss Strong seedling obtained from Seedling Vigor Classification Test
Tt Seed test
TZ-0 Tetrazolium test for undesiccated seed lot
X
TZ-24 Tetrazolium test for 24 hours desiccated seed lot
TZ-96 Tetrazolium test for 96 hours desiccated seed lot
TZ-168 Tetrazolium test for 168 hours desiccated seed lot
V Viability
Viability_Gv Germinable and viable seed obtained from Viability Test
XI
LIST OF TABLES
Table Page
1 Staining intensity of embryo. 34
2 Initial germination (%) and moisture content (%) of J. curcas seeds as
illustrated in Figure 1. 145
3 Mean value of initial germination (%) of J. curcas seeds. 145
4 Initial viability (%) of J. curcas seeds as illustrated in Figure 2. 145
5 Mean value of initial viability (%) of J. curcas seeds. 44
6 Analyses of viability of J. curcas seeds for four accessions and
maturity indexes. 46
7 Classification of stained seeds of J. curcas as illustrated in Figure 3. 47
8.1 Seedling vigor classification for four accessions. 49
8.2
Initial seedling vigor classification of four different accessions and
maturity indexes for germinated J. curcas seeds as extracted in Table
8.1.
146
9 J. curcas seedling lot group classification based on performance of
seedlings. 53
10 Deterioration of J. curcas seed in storage after desiccation up to 168
hours. 67
11.1 Critical seed moisture content (%) at 24 hours desiccation. 150
11.2 Critical seed moisture content (%) at 96 hours desiccation. 151
11.3 Critical seed moisture content (%) at 168 hours desiccation. 152
12.1 Seed moisture content (%) for 30 days stored seed lots. 79
12.2 Seed moisture content (%) for 60 days stored seed lots. 79
12.3 Seed moisture content (%) for 90 days stored seed lots. 80
13.1 Germination (%) for 30 days stored seed lots. 83
XII
13.2 Germination (%) for 60 days stored seed lots. 83
13.3 Germination (%) for 90 days stored seed lots. 84
14.0 Classification of stained seeds of J. curcas as illustrated in Figure 12. 153 -154
14.1 Analyses of viability of 30 days stored J. curcas seed lots for four
accessions, desiccation periods and maturity indexes. 91 - 92
14.2 Analyses of viability of 60 days stored J. curcas seed lots for four
accessions, desiccation periods and maturity indexes. 93 - 94
14.3 Analyses of viability of 90 days stored J. curcas seed lots for four
accessions, desiccation periods and maturity indexes. 95 - 96
15.1 Seedling vigor classification for 30 days stored seed lots. 98
15.2 Seedling vigor classification for 60 days stored seed lots. 99
15.3 Seedling vigor classification for 90 days stored seed lots. 100
16 Anomalous emergence of seedling. 109
17.1 Seed lot group classification based on performance of seedling growth
for 30 days stored seed lots. 111
17.2 Seed lot group classification based on performance of seedling growth
for 60 days stored seed lots. 112
17.3 Seed lot group classification based on performance of seedling growth
for 90 days stored seed lots. 113
18 Ratio of seedling growth and biomass allocation. 124
19 Localities and ecology of the studied sites. 126 - 127
20 Seed oil content, soil and plant nutrient. 130
21 Statistical analyses. 159 - 168
22.1 Viability (%) of live J. curcas seed stored for 30 days as illustrated in
Figure 11.1. 169
22.2 Viability (%) of live J. curcas seed stored for 60 days as illustrated in
Figure 11.2. 169
22.3 Viability (%) of live J. curcas seed stored for 90 days as illustrated in
Figure 11.3. 170
XIII
LIST OF FIGURES
Figure Page
1 Initial germination and moisture content of J. curcas seeds. 43
2 Initial viability of J. curcas seeds. 45
3 Staining pattern and deterioration in fresh embryos of J. curcas
seeds as manifested in tetrazolium reaction. 47
4 Initial seedling growth and biomass allocation of J. curcas. 51
5 Estimated marginal mean for maturity of J. curcas. 55
6.1 Quality of different J. curcas seeds base on performance of
accession from Bintulu. 61
6.2 Quality of different J. curcas seeds base on performance of
accession from Miri. 61
6.3 Quality of different J. curcas seeds base on performance of
accession from Samarahan. 61
6.4 Quality of different J. curcas seeds base on performance of
accession from Sri Aman. 61
7 Weight loss of J. curcas seed lots stored for 30, 60 and 90 days. 63
8.1 Accessions: Weight loss of J. curcas seed stored for 30, 60 and 90
days. 64
8.2 Seed maturity index: Weight loss of J. curcas seed stored for 30, 60
and 90 days. 64
9.1 Weight loss of J. curcas seeds from four maturities in accession
from Bintulu stored for 30, 60 and 90 days. 65
9.2 Weight loss of J. curcas seeds from four maturities in accession
from Miri stored for 30, 60 and 90 days. 65
9.3 Weight loss of J. curcas seeds from four maturities in accession
from Samarahan stored for 30, 60 and 90 days. 65
9.4 Weight loss of J. curcas seeds from four maturities in accession
from Sri Aman stored for 30, 60 and 90 days. 65
XIV
10 Types of deterioration in J. curcas after desiccation up to 168 hours
and stored to 90 days. 66
11.1 Viability of live J. curcas seeds for 30 days stored seed lots. 86
11.2 Viability of live J. curcas seeds for 60 days stored seed lots. 87
11.3 Viability of live J. curcas seeds for 90 days stored seed lots. 88
12 Pattern of staining and deterioration in embryos as manifested in
tetrazolium test reactions. 155-158
13.1 Seedling biomass allocation for 30 days stored seed lots. 115
13.2 Seedling biomass allocation for 60 days stored seed lots. 116
13.3 Seedling biomass allocation for 90 days stored seed lots. 117
14 Estimated marginal means of J. curcas seeds for desiccation prior to
storage. 119
15 Estimated marginal mean of J. curcas seeds for different accessions
prior to storage. 121
16 Estimated marginal mean for J. curcas seeds following desiccation
and storage. 122
17 Estimated marginal mean for J. curcas seeds of different maturity
index. 123
18.1 Plant tissue macronutrient uptake levels. 129
18.2 Plant tissue micronutrient uptake levels. 129
XV
Seed quality and longevity during storage of four Jatropha curcas L. accessions found in
Sarawak
Geffry Ujie Anak Joshua
ABSTRACT
Seeds of Jatropha curcas L. collected from four accessions from Bintulu, Miri, Samarahan
and Sri Aman were studied to determine moisture content, germination, viability and other
related properties (seedling morphogenesis and seed oil content). Outcomes of this
research were crucial for developing and innovating the suitability of seed storage
methodology in retaining quality for future precedent. This study emphasized the effects of
desiccation and storage of seed from three different level of fruit maturity. In addition, an
environmental influence on the mother tree was also studied to determine the relatedness
yield of seed oil content by ecological features and soil property. This study revealed that
the maturity indexes was significant (p = 0.009) to determine the quality of the fresh seed.
However, at post-storage the outcome was vice-versa (p = 0.055) due to seed aging. The
best criterion to determine seed quality at post-storage was by accession where it showed a
significant outcome of p < 0.001 compared to fresh seed (p = 0.051). Desiccation period of
96 hours reduced seed moisture content up to 70% for 60 days of storage was optimal in
minimizing the risk of deterioration caused by fungi and seed biochemical reaction, as well
as retained seed viability. Dry microclimate and ample content of phosphorus, magnesium,
sulfur, copper and zinc elements available in soil were believed as a factor for which
contributed to high oil yield in J. curcas seed.
Key words: Jatropha curcas, accession, desiccation, storage, maturity indexes.
XVI
Kualiti dan jangka hayat semasa penyimpan biji benih Jatropha curcas L. dari empat
aksesi yang ditemui di Sarawak
Geffry Ujie Anak Joshua
ABSTRAK
Biji benih Jatropha curcas L. dari empat aksesi iaitu Bintulu, Miri, Samarahan dan Sri Aman
telah dikaji untuk mengenalpasti kandungan kelembapan, percambahan, kebolehidupan dan
lain-lain sifat berkaitan (morfogenesis anak benih dan kandungan minyak biji). Hasil kajian ini
sangat penting untuk rujukan masa depan demi pembangunan dan inovasi kesesuaian kaedah
penyimpanan biji benih dalam mengekalkan kualiti. Kajian ini memfokuskan kesan
pengeringan dan penyimpanan ke atas biji benih dari tiga tahap kematangan buah. Pengaruh
persekitaran ke atas pokok ibu turut dikaji untuk mengenalpasti perkaitan kandungan minyak
biji yang terhasil dengan ciri-ciri ekologi dan sifat tanah. Hasil kajian menunjukkan bahawa
indeks kematangan adalah signifikan (p = 0.009) dalam penentuan kualiti biji benih segar.
Namun, di peringkat selepas penyimpanan hasil kajian adalah sebaliknya (p = 0.055)
disebabkan proses penuaan biji. Aksesi merupakan kriteria yang paling sesuai digunakan untuk
menentukan kualiti biji benih selepas penyimpanan kerana hasil yang signifikan iaitu p < 0.001
berbanding biji benih segar (p = 0.051). Pengeringan selama 96 jam mengurangkan kandungan
kelembapan biji benih sehingga 70% untuk 60 hari penyimpanan adalah optimum dalam
meminimakan risiko kerosakan disebabkan oleh kulat dan tindakbalas biokimia, serta
memelihara kebolehidupan biji benih. Iklim mikro yang kering dan kandungan elemen
fosforus, magnesium, sulphur, kuprum dan zink yang mencukupi tersedia di dalam tanah
merupakan faktor penyumbang penghasilan minyak tinggi di dalam biji J. curcas.
Kata kunci: Jatropha curcas, aksesi, pengeringan, penyimpanan, indeks kematangan.
1
INTRODUCTION
Currently, rocketing price of world petroleum due to gradual depletion reserves and great
demand for transportation and industries activities has increased the cost of living globally.
Furthermore, the impact of environmental pollution of increasing exhaust emissions
significantly induces notion that mineral oil is irrelevant for future use. Therefore, the
usage of mineral oil should be replaced into alternative energy base on crop. In the context
of growing interest for alternative, renewable and inexpensive energy sources, liquid
bioenergy production from vegetable oils is proposed as one of the possible options to
reduce these concerns.
Biodiesel is monoalkyl ester of fatty acids derived from vegetable oils or animal fats
produced by transesterification with methanol or ethanol (Knothe et al. (2006) cited in
Akbar et al., 2009; Erliza et al., 2007; Veny et al., 2009). Biodiesel has many advantages
such as it is renewable, safe for use in all conventional diesel engines, offer the same
performance and engine durability as petroleum diesel fuel, biodegradable, non-flammable,
non-toxic, less visible smoke, non-noxious fumes and odors, and cost-effective (Akbar et
al., 2009; Erliza et al., 2007; Patil & Deng, 2009). This reason made biodiesel production
from Jatropha curcas L. has become a booming business.
J. curcas is an important and promising source of diesel. Its extracted oil from seed can be
used as it is crushed without being refined, blended with normal diesel and used in car, and
refined and sold as pure diesel (CJP, 2007). This type of biodiesel is the most valuable
form of renewable energy that can be used directly in any existing and unmodified diesel
2
engine (CJP, 2007; Rintos, 2008). The jatropha oil is not characterized as edible oil and its
usage as biodiesel feedstock will not disturb the supply of edible oil and the usage of the
palm oil for oleo chemical industries or CPO export purpose (Erliza et al., 2007). The oil
produced by J. curcas can be easily converted to liquid bio-fuel, which meets the
American and European standards (Achten et al., 2008). Apart from its use as a liquid fuel,
the oil also has been used to produce biocides such as insecticide, molluscicide, fungicide
and nematicide (Achten et al., 2008).
The oil contain of J. curcas is 10 to 50 percent of the seed (CJP, 2007; Erliza et al., 2007;
Fang, 2008; Glicerio, 2007; Rintos, 2008) and 52 to 67 percent of the kernel (Fang, 2008),
which can be processed into Jatropha Methyl Ester (JME) or Jatropha Biodiesel by
transesterification. Due higher viscosity (16 to 18 hydro-carbon atoms per molecule
content), transesterification is performed to reduce viscosity and increasing burning power
in order to use the oil as diesel fuel for vehicles (Erliza et al., 2007). This process changed
triglyceride molecule or a complex fatty acid into methyl ester (biodiesel) and glycerol
using sodium methoxide (mixture of methanol with sodium hydroxide). The reaction
resulting glycerin (glycerol) is left on the bottom and methyl esters (biodiesel) is left on top
(CJP, 2007; Rintos, 2008).
The J. curcas contain toxin such as phorbol esters, curcin, trypsin inhibitors, lectins and
phytates (Achten et al., 2008). This toxin composition makes J. curcas plant is non-edible
either by man or animal, thus it is suitable for a hedge (living fence) by farmer because it is
not browse by animals like cattle or goats (Achten et al., 2008; Reinhard, 2004; Srivastava,
1999 cited in Ginwal et al., 2004). Furthermore, the plant is a valuable multi-purpose crop
3
to alleviate soil degradation, desertification and deforestation (Abdrabbo & Nahed, 2008),
prevent and control soil erosion, and reclaim wasteland (Achten et al., 2008), use as a
source of shade for coffee plants in Cuba and support plant for vanilla plants in Comore
Islands, Papua New Guinea and Uganda (Reinhard, 2004), and as ornamental plant.
In medicinal purpose, it is used for diseases like cancer, piles, snakebite, paralysis, dropsy,
etc. The seeds of J. curcas can be used against constipation, ulcer and tumor. Latex for
wound healing and its alkaloid known as jatrophine, is believed to have anti-cancerous
properties, Leaves as tea against malaria. Root for rheumatism and bark for snakebite
(BATCD, 2007; CJP, 2007; Reinhard, 2004; Satish, n.d.). Furthermore, an extracted curcin
is useful for anti-virus and anti-fungi (Fang, 2008).
Instead of biodiesel as it main product, the by-product, ‘glycerin’ has many uses in soap,
detergent and cosmetic production (Abdrabbo & Nahed, 2008; Rintos, 2008). The pressed
seed residues or press cake which rich in nitrogen, phosphorous and potassium (Abdrabbo
& Nahed, 2008) can be used as a fertilizer, for electricity and heat production and the
organic waste products can be digested to produce biogas (CH4) (Achten et al., 2008;
Rintos, 2008).
To obtain good quality of J. curcas seeds at post-storage, some factors should be taken into
consideration, for instance, the level of fruit maturity, safe seed moisture content,
appropriate storage condition and pre-storage treatment, duration of storage, good viability
and vigor of seeds. Rantje et al. (2008) reported that storage duration gave very significant
differences on the percentages of germination and vigor, total fungal population and lipid
4
contents of J. curcas. Therefore, the increment of storage duration caused the parameters
(germination, vigor, fungal dan lipid content) decreased but for free fatty acid contents and
lipase activity were vice versa. This finding also concluded that the moisture content of J.
curcas was in equilibrium with the relative humidity of the storage. In Christensen and
Kaufmann (1969) finding, during storage seeds or grains could be infected by fungi which
cause a decrease in viability, discolouration, various biochemical changes, heating and
mustiness, loss in weight, and production of toxins when it is consumed may be injurious
to human and domestic animals.
In recent years, there are many studies about J. curcas has been published and mostly
focused on cultivation, propagation, oil utilization, molecularity, genetics and economics
importance. However, a study on storability of J. curcas seed is less reported or published.
Although reported studies are little but the scope of research is aimed on one seed source
(accession) and one seed maturity (physiological or harvest maturity). Hence,
determination for high quality seed could not be ascertained due to lack of comparison
criterion. Moreover, the quality of seedling from post-storage seed is slightly published.
Despite an extensive search, no published literature regarding J. curcas planted in Sarawak
was found on the detailed physical properties and oil content of seed and their dependency
on agronomical parameters, which would be useful for the design of agricultural systems in
future. Therefore this research is essential in order to identify the suitability of seed
storage methodology and documenting the agronomical properties and distribution of J.
curcas crop.
5
The main objectives of this study were to (1) assess viability, vigor, germination and oil
content of four accessions of J. curcas seeds; (2) determine the effect of storage on
viability and germination of J. curcas seeds; (3) determine suitable period of storage for J.
curcas seeds; (4) analyze quality of J. curcas seed based on different fruit maturity index
and accession.
6
LITERATURE REVIEW
Jatropha curcas L.
The J. curcas is belonging to the Euphorbiaceae family. It is a drought-tolerant perennial
and able to survive in very dry soils in condition considered marginal for agriculture
(Erliza et al., 2007; FAO, 2010; Rao et al., 2008). The life expectancy and fruit production
of J. curcas can up to 50 years (Achten et al., 2008; CJP, 2007). However, the economic
life is expected from 30 to 50 years (FAO, 2010). J. curcas grows in tropical and sub
tropical regions, with cultivation limits at 30oN and 35
oS has its native distributional range
in Mexico, Central America, Brazil, Bolivia, Peru, Argentina and Paraguay (Achten et al.,
2008; FAO, 2010). Now it has been domesticated in a widespread manner in Africa and
Asia due to its adaptive ability (Rao et al., 2008; Srivastava, 1999 cited in Ginwal et al.,
2004). It also grows in lower altitudes of 0 to 1000 meters above sea level with optimum
rainfall range of 600 to 800 mm/year (Abdrabbo & Nahed, 2008; Erliza et al., 2007; FAO,
2010; Ginwal et al., 2004). It grows well in optimum temperatures between 20oC to 28
oC
(Erliza et al., 2007; FAO, 2010) and well adapted to conditions of high light intensity
(Jongschaap, 2007 cited in FAO, 2010).
J. curcas is a small tree or large shrub with irregular branch, wooden cylindrical stem and
smooth gray bark, which exudes whitish coloured, watery, latex when cut (Erliza et al.,
2007; CJP, 2007). It can reach a height up to 1-7 meter tall or more under favourable
condition. J. curcas is deciduous, shedding the leaves in the dry season. Flowering occurs
throughout the year (Heller, 1996 cited in FAO, 2010) and at peak during wet season (CJP,
7
2007). Normally, the flowers are pollinated by insects especially honey bees. Below are the
morphological characteristics of J. curcas:
i. Leaf
The leaf is broad (10 to 15 cm length and width) with 4 to 6 lobed, smooth, colored
green (adaxial) to pale-green (abaxial) and spiral phyllotaxis with alternate to sub-
opposite position. It is hollow, stripes and pointed at the end. The petiole is about 4
to 15 cm long. (Achten et al., 2008; CJP, 2007; Erliza et al., 2007)
ii. Flowers
The plant is monoecious and the terminal inflorescences which are formed in the
leaf axil contain unisexual flowers. The stalk length ranges between 6 to 23 mm.
Flowers are formed terminally, individually, with female flowers usually slightly
larger and occurs in the hot seasons. The ratio of male to female flowers ranges
from 13:1 to 29:1 and decreases with the age of the plant (Achten et al., 2008). In
conditions where continuous growth occurs, an unbalance of pistillate or staminate
flower production results in a higher number of female flowers (CJP, 2008).
iii. Fruits
After pollination, the inflorescences form a bunch of green ellipsoidal fruits. Each
inflorescence yields a bunch of approximately 10 or more fruits. A three, bi-valved
cocci is formed after the seeds mature and the fleshy exocarp dries (Achten et al.,
2008; CJP, 2007).