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 'Gros Michel' has been replaced by the current main banana on the market, the 'Cavendish', which in turn is (2015) at risk of total loss to a strain of the same fungus, 'Tropical Race 4'.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
Crop diversity can be the result of genetic differences: a crop may have genes conferring early maturity or disease resistance Such traits collectively determine a crop's overall characteristics and their future potential. Diversity within a crop includes genetically-influenced attributes such as seed size, branching pattern, height, flower color, fruiting time, and flavor. Crops can also vary in less obvious characteristics such as their response to heat, cold, a drought, or their ability to resist specific diseases and pests. Modern plant breeders develop new crop varieties to meet specific conditions. A new variety might, for example, be higher yielding, more disease resistant or