Forecasting Model for Wilt of Banana By Md. Kamaruzzaman Shakil
FORECASTING MODEL FOR BANANA WILT SUBMITED TO SUBMITED BY Md. Kamaruzzaman ID No. 11 Ag.P.Path. JJ 07 MDepartment of Plant Pathology Reg. No. 33141Bangladesh Agricultural University Department of Plant PathologyMymensingh Bangladesh Agricultural University Mymensingh Ph.- +8801722449614 DEPARTMENT OF PLANT PATHOLOGY BANGLADESH AGRICULTURAL UNIVERSITY MYMENSINGH
IntroductionBanana is one of the most important food and cash crop in Bangladesh andgrown around the year in the country as a commercial purpose andhomestead area for local consumption. In addition, banana stood firstposition among the fruits producing in the country and supplies 42% of thetotal fruit requirements in the country and also its financial return as a cropis higher compared to other fruits and field crops (Haque, 1988). Banana is avery versatile crop. The whole plant or fruit, leaves, stem and other plantparts play a major role in the daily activity or use by the local populationwhere they have multiple uses. While some of the uses form part of the dailyactivity of the population such as food wrapper, whole plants at ceremonies,landscaping, pharmaceuticals, rope, paper and viable commercial industry.DISEASE: Wilt of BananaCAUSAL ORGANISM: Fusarium oxysporum f. sp. cubense (Foc) Fig. Fusarium Wilt of BananaSymptoms: 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 bysmallholders for local consumption. Factors affecting forecasting are asfollows- Host Pathogen Weather TimeHOST FACTORSDifferent variety of banana plant shows different reaction with the pathogenof wilt of banana. If there are resistance variety then less chance to epidemicformation.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 ofepidemic formation are very high rather than reverse situation. Host growthstage 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 FACTORSEnvironmental factors are the major consideration of different stages ofgrowth. 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 directeffect on the pathogen and has indirect effect by influencing life cycle of thepathogen. On the Fusarium oxysporum f. sp. cubense (Foc) preferdevelopment of the disease in high temperatures and warm moist soils.Banana is mainly tropical crop and 27°C temperature is optimum for normalgrowth and development. If temperature raised above 38°C the growth anddevelopment stopped and if temperature fall down to below 10°C then cropperiod extended and reduced the bunch weight (Haque, 2008). The optimumtemperature for growth in between 25-30°C, and the optimum soiltemperature for root infection is 30°C or above. Rain fall play crucial rolefor disease development.TIME FACTORSFusarium oxysporum f. sp. cubense (Foc) infects banana plant during themonth of July-August. The duration of infection, incubation, sporulation,dissemination and of the complete disease cycle, the timing of critical stagesand the length and sequences of significant periods in disease outbreak areconsidered for forecasting.CRITICAL WEATHEMinimum temperature 24-32ºCRelative humidity above 95%Moist and damp weatherCRITICAL GROWTH:Tertiary roots emergence stage.
CRITICAL WEATHER MODEL: Fig. Forecasting model for Wilt of BananaMANAGEMENT PRACTIC:Chemical control, fumigation, crop rotation and the use of organicamendments have not been effective in managing Fusarium wilt. Since noresistant cultivars are available to replace Cavendish bananas in many partsof the world, quarantine and exclusion procedures are the only effectivemeans to control the disease. This can be achieved by restricting themovement of corms, suckers and soil that could be carrying Foc frominfested to clean areas. Planting material propagated in accredited tissueculture laboratories should be free of the pathogen. Once Fusarium wilt hasbeen discovered in a field, infected and surrounding plants should beisolated by fencing-off and killed by injecting it with a herbicide. The use ofSporekill as a disinfectant is encouraged to sterilize farming equipment. Allnew outbreaks should be reported immediately.
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