This is an analytical scientific paper concern about forecasting of diseases.

1. FORECASTING MODEL FOR BANANA WILT
SUBMITED TO SUBMITED BY
Md. Kamaruzzaman
ID No. 11 Ag.P.Path. JJ 07 M
Department of Plant Pathology Reg. No. 33141
Bangladesh Agricultural University Department of Plant Pathology
Mymensingh Bangladesh Agricultural University
Mymensingh
Ph.- +8801722449614
DEPARTMENT OF PLANT PATHOLOGY
BANGLADESH AGRICULTURAL UNIVERSITY
MYMENSINGH

2. 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.

3. 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.

4. 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.

5. 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.

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