Crop diversity are all susceptible to a single fungus, "Fusarium oxysporum" (Panama disease); large areas of the crop were destroyed by the fungus in the 1950s. 'Gros Michel' has been replaced by the current main banana on the market, the 'Cavendish', which in turn is (2015) at risk of total loss to a strain of the same fungus, 'Tropical Race 4'. Such threats can be countered by strategies such as planting multi-line cultivars and cultivar mixes, in the hope that some of the cultivars will be resistant to any individual outbreak of disease. The implications of crop diversity are at both local
Panama disease upwards of 30 years. When the environment is ideal and there are host roots available, these chlamydospores will germinate and hyphae will penetrate the roots, initiating infection. There is in increase in the number of symptomatic plants when inflorescences emerge and the highest disease incidence occurs right before harvest. Once infected, microconidia are produced and present within the vessels of the plant’s vascular system. Macroconidia are another asexual spore that tends to be found on the surface of plants killed by Panama disease. Infection is systemic, moving through the vascular system and causing yellowing and buckling that starts in older