INCIDENCE AND SEVERITY OF ANTHRACNOSE (Colletotrichum lindemuthianum) ON SELECTED COMMON BEAN (Phaseolus vulgaris L.) GENOTYPES

Abstract

Common bean (Phaseolus vulgaris L.), is among the most important legume crop for protein source in peoples’ diet globally and including Kenya. Anthracnose (Colletotrichum lindemuthianum) is a common disease of legumes that causes yield loss of upto 90-100%. Potential production of common beans in Kenya is expected to be above 2000 kg ha-1 but due to challenges of pests and diseases among them anthracnose, it remains below potential yields. The aim of the recent study was to investigate selected common bean genotypes for anthracnose resistance in Kenya. The study was done in three varied agro-ecological zones; Busia, Bungoma and University of Eldoret. Fifteen genotypes were evaluated on field experiment to ascertain anthracnose incidence and severity. Four bean genotypes were used as experimental controls; two resistant and two susceptible controls. Data was collected on incidences and severity and subjected to Analysis of variance in SAS version 9.1. Mean values were separated using Tukeys’ Studentized Range Test. The results revealed tolerant and resistant genotypes with lower incidences and severity than those of resistant controls while susceptible genotypes recorded higher incidences and severity than those of the susceptible controls. Tolerant genotypes were; Ciankui, Tasha, and KK8 while the resistant genotypes were; Miezi mbili, KK15 and Chelalang. Site variation was significant at (P≤0.05) with Busia 82%, Bungoma 76% and University of 53%. KK15, Tasha and Chelalang were tolerant in all sites, and this could be attributed to their genetic resistance. The six genotypes identified to be potentially tolerant and resistant to anthracnose and high yielding could be further studied and used in breeding programs for development of resistant lines globally and in Kenya.