EVALUATION OF BOTANICAL EXTRACTS FOR THE POST-HARVEST MANAGEMENT OF WHITE YAM FUNGAL DISEASES

Abstract

Post-harvest rot in white yam (Dioscorea cayenensis subsp. rotundata) is a major challenge in storage, contributing to food insecurity in yam-producing regions. This study investigated the fungal pathogens responsible for post-harvest rot in white yams obtained from selected markets in Lagos, Nigeria, and evaluated the antifungal efficacy of plant extracts as a sustainable control method. Fungi isolated from diseased tubers were subjected to pathogenicity tests, and virulent strains were identified through molecular characterization. Two virulent fungi—Penicillium oxalicum strain LBCCN_YS_A3 and Aspergillus niger strain LBCCN_YS_A8—were confirmed to induce rot in healthy yam tubers within 14 days. Ethyl acetate and n-hexane extracts of Pseudocedrela kotschyi, Parkia biglobosa, and Mezoneuron benthamianum were tested for antifungal activity using the agar well diffusion method. Among the extracts, P. biglobosa exhibited the highest inhibitory effect on fungal growth. The findings suggest that P. biglobosa extract is a promising biocontrol agent and could serve as an eco-friendly alternative to synthetic fungicides in managing post-harvest yam rot.