Fungitoxic and Phytotoxic Effect of Vernonia amygdalina (L), Bryophyllum pinnantus Kurz Ocimum gratissimum (Closium) L. and Eucalyptna globules (Caliptos) Labill Water Extracts on Cowpea and Cowpea Seedling Pathogens in Ago-Iwoye, South Western Nigeria

A study to evaluate the fungitoxic and phytotoxic effects of extracts of V. amaygdalina, B. pinnatus, O. gratissimum and E. globules on the fungal pathogens inducing wilting on cowpea grown in Ago-Iwoye, South Western Nigeria. The extracts of all the botanicals used reduced Disease Infection Rate (DIR) in treated plants. Sclerotium rolfsii sacc induced wilting of between 4 and 12% on cowpea seedlings treated with plant extract under field conditions while about 39.6% incidence of cowpea seedlings wilting was observed under control experiment on the same experimental plot. The extracts increased significantly the plant height, shelf life, relative water content and chlorophyll contents of the cowpea seedlings during both the wet and dry season. On the other hand, the extracts significantly (p = 0.05) reduced transpiration rate and stomata aperture of treated plant in both seasons. Furthermore, application of these extracts on the cowpea plants significantly enhanced the Leaf Area Index (LAI) number of branches and ponds per plant, total dry matter per plant, weight per pod, 100 grains weight and grain yield in both season when compared with the values obtained from control plants. The extracts also inhibited the release of current photosynthethates from treated plants thus maintaining the water status of plant and also making photosynthethates which can be oxidized to release energy needed for growth available to treated plants.