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 'Gros Michel' has been replaced by the current main banana on the market, the 'Cavendish', which in turn is (2015) at risk of total loss to a strain of the same fungus, 'Tropical Race 4'.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
Scald (barley disease) of the disease involves the use of clean and/or treated seeds, resistant cultivars, crop rotation, residue management, and foliar fungicides. Cultivars with scald resistance are available in all major barley growing areas. The level of resistance occurs along a spectrum and the degree of resistance that is required to effectively control the disease will depend on the region where it is grown, cropping practices that reduce initial disease inoculum, wetter conditions and fungal pathotypes. Foliar fungicides can be used to effectively control disease development. Product selection, application rates and timing, depend upon numerous factors. The availability of fungicides as a