FORECASTING MODEL FOR BANANA WILT

SUBMITED TO SUBMITED BY

DEPARTMENT OF PLANT PATHOLOGY BANGLADESH AGRICULTURAL UNIVERSITY

MYMENSINGH

Department of Plant Pathology

Bangladesh Agricultural University

Mymensingh

Md. Kamaruzzaman ID No. 11 Ag.P.Path. JJ 07 M Reg. No. 33141 Department of Plant Pathology

Bangladesh Agricultural University

Mymensingh

Ph.- +8801722449614

Introduction

Banana is one of the most important food and cash crop in Bangladesh and

grown around the year in the country as a commercial purpose and

homestead area for local consumption. In addition, banana stood first

position among the fruits producing in the country and supplies 42% of the

total fruit requirements in the country and also its financial return as a crop

is higher compared to other fruits and field crops (Haque, 1988). Banana is a

very versatile crop. The whole plant or fruit, leaves, stem and other plant

parts play a major role in the daily activity or use by the local population

where they have multiple uses. While some of the uses form part of the daily

activity of the population such as food wrapper, whole plants at ceremonies,

landscaping, pharmaceuticals, rope, paper and viable commercial industry.

DISEASE: Wilt of Banana

CAUSAL ORGANISM: Fusarium oxysporum f. sp. cubense (Foc)

Fig. Fusarium Wilt of Banana

Symptoms:

1. Yellowing of oldest leaves (spreads from leaf margins) and then

the yellowing process progresses from the older to the younger leaves.

2. Oldest leaves then collapse at the petiole: it gives the

appearance of a skirt around the plant.

3. Break down of leaf near to the petiole and hanging die.

4. In young plants, dwarfing or stunting may occur.

IMPORTANT FACTORS FOR FORECASTING:

Fusarium wilt is a serious problem on many banana cultivars grown by

smallholders for local consumption. Factors affecting forecasting are as

follows-

Host

Pathogen

Weather

Time

HOST FACTORS Different variety of banana plant shows different reaction with the pathogen

of wilt of banana. If there are resistance variety then less chance to epidemic

formation.as a result no need for forecasting. Resistance variety such Sagor,

Champa, Sobri, Kobri, Mehersagar, BARI Kola-1are less susceptible to wilt.

If the same variety of banana are planting in a locality, that time chance of

epidemic formation are very high rather than reverse situation. Host growth

stage play crucial role for diseases development.

PATHOGEN FACTORS

Amount of primary infection: Higher amount of primary infection

lead to the development of epidemic infection of a disease which

strongly correlated to secondary spread of the causal agent Fusarium

oxysporum f. sp. cubense under favorable conditions of host and

environment.

Primary inocula: Forecasting without analysis of appropriate

information on primary inoculum might not be successful.

Inoculum potential: Forecasting need critical information about the

inoculum potential which is the ability of inoculum to produce

successful infection.

Rate of germination of spore: F. oxysporum has no known sexual

stage, but produces three types of asexual spores: microconidia,

macroconidia, and chlamydospores. The micro conidia are the most

abundantly produced spores. Soil water content, from wilting point to

80% field capacity, had little effect on germination of chlamydospores

in either soil.

Mechanism of release of inocula: Easy and quick release of the

inocula influences the infection process for epidemic development of

Wilt of banana.

ENVIRONMENTAL FACTORS

Environmental factors are the major consideration of different stages of

growth. This factor includes suitable temperature, high relative humidity,

rainfall, dew, light, wind, sunshine, evaporation, atmospheric pressure.

Epiphytotic develop when favorable combinations of these elements occur.

The data on climatic conditions are used for forecasting. Weather has direct

effect on the pathogen and has indirect effect by influencing life cycle of the

pathogen. On the Fusarium oxysporum f. sp. cubense (Foc) prefer

development of the disease in high temperatures and warm moist soils.

Banana is mainly tropical crop and 27°C temperature is optimum for normal

growth and development. If temperature raised above 38°C the growth and

development stopped and if temperature fall down to below 10°C then crop

period extended and reduced the bunch weight (Haque, 2008). The optimum

temperature for growth in between 25-30°C, and the optimum soil

temperature for root infection is 30°C or above. Rain fall play crucial role

for disease development.

TIME FACTORS

Fusarium oxysporum f. sp. cubense (Foc) infects banana plant during the

month of July-August. The duration of infection, incubation, sporulation,

dissemination and of the complete disease cycle, the timing of critical stages

and the length and sequences of significant periods in disease outbreak are

considered for forecasting.

CRITICAL WEATHE

Minimum temperature 24-32ºC

Relative humidity above 95%

Moist and damp weather

CRITICAL GROWTH:

Tertiary roots emergence stage.

CRITICAL WEATHER MODEL:

Fig. Forecasting model for Wilt of Banana

MANAGEMENT PRACTIC:

Chemical control, fumigation, crop rotation and the use of organic

amendments have not been effective in managing Fusarium wilt. Since no

resistant cultivars are available to replace Cavendish bananas in many parts

of the world, quarantine and exclusion procedures are the only effective

means to control the disease. This can be achieved by restricting the

movement of corms, suckers and soil that could be carrying Foc from

infested to clean areas. Planting material propagated in accredited tissue

culture laboratories should be free of the pathogen. Once Fusarium wilt has

been discovered in a field, infected and surrounding plants should be

isolated by fencing-off and killed by injecting it with a herbicide. The use of

Sporekill as a disinfectant is encouraged to sterilize farming equipment. All

new outbreaks should be reported immediately.

Literature Cited :

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Fusarium wilts with nonpathogenic fusaria. p.415–426. In: E.C. Tjamos,

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