In vivo Evaluation of Plant Extracts against Common Phytopathogenic Fungi Isolated from Pawpaw (Carica papaya L.)

Abstract

Plants possess various efficacious natural products to curtailing various problems associated with man and his environment. Fungi cause significant postharvest losses to global pawpaw (Carica papaya) production, particularly in Africa. Current control methods focus primarily on synthetic fungicides that are hazardous to the environment, while plant-based fungicides are characterised with biofriendly and costeffective potential. In this study, three plant extracts were investigated for their in vivo antifungal property opposed to three phytopathogenic mycoflora isolated from Carica papaya post harvest. Aqueous extracts of Moringa oleifera, Telfaira occidentalis and Bauhinia monandra leaves were evaluated at aaglomerations of 150 mg/ml and 75 mg/ml for their antifungal properties in papaya fruits for 7 days. In vivo antifungal evaluation revealed that the three plant extracts showed varying degrees of inhibitory activity against Aspergillus niger, Aspergillus flavus and Rhizopus oryzae. Of the three evaluated plants, B. monandra showed higher antifungal activity during the post-inoculation period. The concentration of 150 mg/ml of aqueous extracts of the plants preserved the fruits and inhibited fungal growth in a range of 3-5 days, while the 75mg/ml concentration of Moringa oleifera, Telfiaria occidentalis and Bauhinia monandria inhibited fungal growth for 3, 2 and 3 days after inoculation, respectively. Significant weight loss was observed in fruits inoculated for both treatments and controls at both concentrations (p-value <0.05). This experimentation has ssubstantiated that the aqueous leaf extracts of M. oleifera, T. occidentalis, and B. monandra possess the potential as natural antifungals for the control and management of fungal diseases