Reaction of Selected Kenyan Bean Cultivars to Phaeoisariopsis griseola

Pathogenic variation of Phaeoisariopsis griseola in Kenya was investigated. Nineteen isolates from different regions in the country were studied on a set of 10 Kenyan bean cultivars and also on 9 differential cultivars recommended by Centro International de Agriculture Tropical (CIAT). The first trifoliate leaf was inoculated with a spore concentration of 2 × 104 spores/ml and plants were evaluated for disease reaction two weeks after inoculation. Disease reaction was classified using CIAT scale. Differences were found in virulence among isolates. Eleven pathogenic groups were identified from fifteen isolates. Kenyan bean cultivar GLP 24 and GLPX 1231 were highly resistant to P. griseola isolates used whereas cultivar GLPX 1127(a), GLPX 1129 and GLPX 1159 were susceptible to all isolates. CIAT differential cultivars RAB 206 and BAT 1647 were resistant to all the isolates of P. griseola used in this study. Key Words: Angular leaf spot, foliar disease Journal of Tropical Microbiology Vol.1(1) 2002: 2-