Incidence and severity of bean common mosaic disease and resistance of popular bean cultivars to the disease in western Kenya

摘要: The common bean (Phaseolus vulgaris) is a high protein crop and the main legume in cropping system of western Kenya. Despite its importance, yields are low (<1.0 t/ha) declining. Bean mosaic virus (BCMV) necrosis (BCMNV) most destructive viruses can cause yield loss as 100%. In Kenya, limited number cultivars exotic genotypes with resistance to BCMV BCMNV strains have been reported. This study sought determine distribution screen popular for viruses. October 2016 May 2017, two diagnostic surveys disease (BCMD) were conducted seven counties Kenya namely Bungoma, Busia, Homa Bay, Nandi, Vihiga, Kakamega Siaya. Leaf samples showing virus‐like symptoms collected analysed by ELISA. Sixteen popularly grown together cowpea (Vigna unguiculata), soybean (Glycine max), green grams radiata) groundnut (Arachis hypogaea) planted greenhouse completely randomized block design three replicates. plants inoculated isolate at 3‐leaf stage. Data taken weekly 3 weeks on type expressed infected. total, 270 farms visited. Symptoms mosaic, downward curling, local lesions, stunting or combination these observed during both surveys. Mean incidence was higher short rain season (50.2%) than long (35.6%). mean BCMD severity scale 0–3 highest (2.3) County lowest (0.5) On variety tests isolate, 10 susceptible, four tolerant resistant. widely distributed across probably because use uncertified seeds farmers inoculum pressure from seed aphid vector. For improved bean, should be advised plant certified all legumes system.