EVALUATION OF NEEM AND GARLIC EXTRACTS IN THE MANAGEMENT OF CHARCOAL ROT DISEASE OF COWPEA (VIGNA UNGUICULATA (L.) WALP.) CAUSED BY MACROPHINA PHASEOLINA (“TASSI.” GOID)

Abstract

Antifungal activities of Azadirachta indica (A. Juss) and Allium sativum (L.) were assessed against M. phaseolina of cowpea in both in-vitro and in-vivo studies at 20%, 40%, 60%, and 80% concentrations respectively using cold (35o C) and hot (70o C) water extractions with a standard fungicide, negative and positive control inclusive. For the in-vitro study, 10 ml of M. phaseolina spore suspension at 106 spores/ ml were drawn into each Petri dish lined with cotton wool. Thereafter, 0.5 g of dry starch was mixed with 5 ml of the various concentrations prepared. Cowpea seeds were dressed with the garlic extract/starch slurry for 5 minutes before transferring into Petri dishes. For the in-vivo experiment, perforated polythene bags filled with sterilized soil were inoculated with 50mls of harvested spores of M. phaseolina at 106 spores/ ml and were allowed to stay for 48 hours. The procedure carried out in-vitro was repeated before planting into soil. The data collected were subjected to analysis of variance, and means were separated using Tukey’s test at 5% level of probability. Hot neem at 20% concentration (96.67%) enhanced percentage germination, Dress force® (100.00%) had a higher significant effect on seedling establishment, Cold neem at 60% concentr ation (51.25 cm) significantly increased plant height. Hot garlic at 40% had the highest significance on number of leaves (75.50), Cold garlic at 20% concentration resulted in significant reduction of disease incidence (10.98%) and increased yield (25.67), Dress force® and hot garlic 60% had significant reduction on disease severity (2.00). The antifungal properties of Azadirachta indica and Allium sativum as seen in this study raise hope in the use of botanicals to manage fungal pathogen