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,
High plains disease for the wheat curl mite. High plains disease also may occur on barley, oats and rye, and on drooping brome "Bromus tectorum" and yellow foxtail "Setaria pumila" grasses. An ELISA test is available to detect high plains disease. Infection can be avoided by elimination of volunteer crop and wild host plants prior to planting. Resistant varieties of maize exist. High plains disease High plains disease is a viral disease afflicting wheat and maize. It is caused by the negative-sense ssRNA virus wheat mosaic virus. Symptoms are similar to wheat streak mosaic virus, with leaf veins showing yellow flecks and streaks,