Crop diversity between 20 and 90 percent crop losses in the Congo. The FAO emergency relief and rehabilitation program is assisting vulnerable returnee populations in the African Great Lakes Region through mass propagation and distribution of CMD resistant or highly tolerant cassava. A well known occurrence of disease susceptibility in crops lacking diversity concerns the 'Gros Michel', a seedless banana that saw world marketing in the 1940s. As the market demand became high for this particular cultivar, growers and farmers began to use the Gros Michel banana almost exclusively. Genetically, these bananas are clones, and because of this lack of genetic diversity,
Brown blotch disease blotch disease causes large economic losses due to a perceived decrease in quality, even though it does not cause any health problems in humans. Brown blotch disease is observed in mushroom farms all over the world. In the UK, the Netherlands and France, 15% of the crop weight is affected by brown blotch disease, while in Italy it is even worse; in the worst years, 40% of the total weight of mushroom crops is affected by brown blotch disease in Italy. Because brown blotch disease affects all mushroom species, exotic mushrooms grown in eastern countries such as Japan, China, and