Cases Studies

Abstract

Common bean ( Phaseolus vulgaris L.) is the most important legume crop in Kenya and is cultivated on an estimated 700,000 ha. A low average yield of 750 kg/ha is realized, against a potential of 1500 kg/ ha (Rheenen et al., 1981). The major constraints to bean production are diseases, soil fertility, insect pest and low erratic rainfall (Otsyula et al., 1998). Common bean is plagued by a wide range of plant parasitic nematodes, but only Meloidogyne spp. are of economic importance, causing up to 60% losses in yield (Ngundo and Taylor, 1974, Kimenju et al., 1999). Apart from the direct losses resulting from root deformation, nematode infection is also known to break host resistance to other pathogens and to suppress nodulation. Several strategies have been developed for the control of root-knot nematode but their adoption level by smallhold farmers is limited (Table 1). This study was undertaken with ultimate aim of developing an integrated strategy of managing root-knot nematodes on beans