Management of anthracnose disease of cowpea with three plant leaf extracts for enhanced grain yield in Abeokuta, Nigeria

Abstract

The antifungal activity of aqueous three plants leaf extracts were tested against anthracnose disease of cowpea caused by Collectotrichum lindemuthianum. The experiment was laid out in a Randomized Complete Block Design (RCBD) with three replicates. Extracts of Azadirachta indica, Acalypha wilkisiana and Carica papaya were sprayed on cowpea (Ife brown) foliage. A total of four foliar sprays were applied: three wee ks after planting, flowering stage, at the initial podding stage and at the full podding stage. Benlate served as positive controls while distilled water was negative control. Results showed the disease incidence and severity as 23.67-46.67% and 1.07-1.93, respectively. Combination of the extracts resulted in significantly (p≤0.05) low incidence of anthracnose (66.67% reduction) and improved the yield of cowpea by 1.63 tons/ha (77.25% increase) compared with untreated control plots. Azadirachta indica, Acalypha wilkisiana and Carica papaya extracts, singly or in combinations, reduced incidence and severity of anthracnose which translated to yield increase. Keywords: Anthracnose, botanicals, Collectotrichum lindemuthianum, cowpea, and management