Resistance of nutrient-rich bean varieties to major biotic constraints in Kenya

Common bean, Phaseolus vulgaris L., is valued as a major source of affordable protein and minerals, and a \nsource of income and employment for rural communities. It is an important staple in the diet of people of all income \ncategories, with consumption levels in eastern and southern Africa exceeding 50kg per person per year, reaching 66 kg \nper person in parts of Kisii. Productivity of common bean in Kenya is severely constrained by abiotic and biotic \nstresses, especially diseases such as angular leaf spot, anthracnose, rust, common bacterial blight, bean common mosaic \nvirus (BCMV), Fusarium wilt and root rots. This study was undertaken to evaluate 27 newly identified bean varieties \nwith high iron and zinc concentration for resistance to the major diseases under field conditions. Eight varieties (RWR \n10, K 132, MCM 2001, G5686, PVA 8, Soya Fupi, Nguaku Nguaku and Nain De Kyondo) showed high (grade 1 to 3) \nto moderate (grade 5) levels of resistance to anthracnose, bean rust, common bacterial blight, bean common mosaic \nvirus and root rot. Variety Kiangara had good levels of resistance to all the diseases. These results indicate that some of \nthe newly identified nutrient-rich bean varieties possess good levels of resistance to diseases and their adoption would, \ntherefore, increase bean production and improve human health.