1 pests, diseases, , natural disasters
1.1 panama disease
1.1.1 tropical race 4
1.2 black sigatoka
1.2.1 in east africa
1.3 banana bunchy top virus
1.4 banana bacterial wilt
pests, diseases, , natural disasters
banana bunches encased in plastic bags protection. bags may coated pesticides.
while in no danger of outright extinction, common edible banana cultivar cavendish (extremely popular in europe , americas) become unviable large-scale cultivation in next 10–20 years. predecessor gros michel , discovered in 1820s, suffered fate. bananas, cavendish lacks genetic diversity, makes vulnerable diseases, threatening both commercial cultivation , small-scale subsistence farming. commentators remarked variants replace of world considers typical banana different people not consider them same fruit, , blame decline of banana on monogenetic cultivation driven short-term commercial motives.
panama disease
panama disease caused fusarium soil fungus (race 1), enters plants through roots , travels water trunk , leaves, producing gels , gums cut off flow of water , nutrients, causing plant wilt, , exposing rest of plant lethal amounts of sunlight. prior 1960, commercial banana production centered on gros michel , highly susceptible. cavendish chosen replacement gros michel because, among resistant cultivars, produces highest quality fruit. however, more care required shipping cavendish, , quality compared gros michel debated.
according current sources, deadly form of panama disease infecting cavendish. plants genetically identical, prevents evolution of disease resistance. researchers examining hundreds of wild varieties resistance.
tropical race 4
tropical race 4 (tr4) reinvigorated strain of panama disease first discovered in 1993. virulent form of fusarium wilt has wiped out cavendish in several southeast asian countries. has yet reach americas; however, soil fungi can carried on boots, clothing, or tools. how tr4 travels , route latin america. cavendish highly susceptible tr4, , on time, cavendish eliminated commercial production disease. known defense tr4 genetic resistance.
black sigatoka
black sigatoka fungal leaf spot disease first observed in fiji in 1963 or 1964. black sigatoka (also known black leaf streak) has spread banana plantations throughout tropics infected banana leaves used packing material. affects main cultivars of bananas , plantains (including cavendish cultivars), impeding photosynthesis blackening parts of leaves, killing entire leaf. starved energy, fruit production falls 50% or more, , bananas grow ripen prematurely, making them unsuitable export. fungus has shown ever-increasing resistance treatment, current expense treating 1 hectare (2.5 acres) exceeding $1,000 per year. in addition expense, there question of how long intensive spraying can environmentally justified. several resistant cultivars of banana have been developed, none has yet received commercial acceptance due taste , texture issues.
in east africa
with arrival of black sigatoka, banana production in eastern africa fell on 40%. example, during 1970s, uganda produced 15 20 tonnes (15 20 long tons; 17 22 short tons) of bananas per hectare. today, production has fallen 6 tonnes (5.9 long tons; 6.6 short tons) per hectare.
the situation has started improve new disease-resistant cultivars have been developed international institute of tropical agriculture , national agricultural research organisation of uganda (naro), such fhia-17 (known in uganda kabana 3). these new cultivars taste different cabana banana, has slowed acceptance local farmers. however, adding mulch , manure soil around base of plant, these new cultivars have substantially increased yields in areas have been tried.
the international institute of tropical agriculture , naro, funded rockefeller foundation , cgiar have started trials genetically modified bananas resistant both black sigatoka , banana weevils. developing cultivars smallholder , subsistence farmers.
banana bunchy top virus
banana bunchy top virus (bbtv) jumps plant plant using aphids. stunts leaves, resulting in bunched appearance. generally, infected plant not produce fruit, although mild strains exist allow production. these mild strains mistaken malnourishment, or disease other bbtv. there no cure; however, effect can minimized planting tissue-cultured plants (in vitro propagation), controlling aphids, , removing , destroying infected plants.
banana bacterial wilt
banana bacterial wilt (bbw) bacterial disease caused xanthomonas campestris pv. musacearum. after being identified on close relative of bananas, ensete ventricosum, in ethiopia in 1960s, bbw occurred in uganda in 2001 affecting banana cultivars. since bbw has been diagnosed in central , east africa including banana growing regions of rwanda, democratic republic of congo, tanzania, kenya, burundi, , uganda.
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