Efficacy of plant extracts for suppression of collar rot and web blight pathogen of cowpea under in vitro conditions

An attempt was made to evaluate the antifungal and biofumigant efficacy of various plants for suppression of Rhizoctonia solani, the incitant of collar rot and web blight of cowpea, under in vitro conditions. Aqueous extracts of different plants viz. cabbage (Brassica oleracea var. capitata), cassava (Manihot esculenta), garlic creeper (Mansoa alliacea), lemon grass (Cymbopogon flexuosus), moringa (Moringa oleifera), mustard (Brassica juncea), neem (Azadirachta indica), papaya (Carica papaya), radish (Raphanus sativus), sweet potato (Ipomoea batatas), wild mustard (Sinapsis arvensis) were tested by poisoned food technique and data revealed that incorporation of cabbage and garlic creeper at a concentration of 12.5% into the medium gave 100% suppression of the pathogen and was superior to all other treatments. In the experiment to evaluate the biofumigant nature of the tested plants, complete suppression of the pathogen was noticed in cabbage and garlic creeper which gave 100% suppression of the pathogen and were found to be superior to all the other treatments. Other test plants mainly radish, moringa, neem and lemon grass caused suppression of 87.88%, 83.33%, 77.88% and 76.66%, respectively.