The harmful effect of synthetic pesticides on the environment and human health calls for sustainable plant and animal disease management. The study's objective was to evaluate the antifungal activities of red onion peel extract on papaya fruit rot fungal pathogens. Onion peel methanol extract at 5, 10, 15, 20, and 25mg/ml concentration was employed to assess the fungal inhibition. In contrast, the extract diluted with 1 mL of potato dextrose agar broth at 100, 50, 25, 20, 15, 10, and 5 mg/Ml, was utilised to assess the in-vitro minimum inhibitory concentration (MIC), in the Department of Plant Science and Biotechnology at Imo State University in Owerri, Nigeria. The identified pathogens include Rhizopusstolonifer, Fusariumoxysporium, and Aspergillusflavus. As pergillusflavus had the largest percentage frequency of occurrence (55%), while, Fusariumoxysporium displayed the lowest frequency (11%). The inhibitory effect of onion peel extract concentrations on the growth of the fungi exhibits an inverse relationship. The mancozeb treatment exhibited the lowest recorded minimum inhibitory concentration (MIC) values. The application of DMSO resulted in the highest observed minimum inhibitory concentration (MIC) values. The concentration of Onion peel extract exhibited an inverse relationship with the Minimum Inhibitory Concentration (MIC) values. The concentration of 100 mg/ml yielded the lowest minimum inhibitory concentration (MIC) value, whereas 5 mg/ml yielded the highest MIC value. The utilisation of red onion peel presents a potential non-chemical and sustainable strategy for managing plant diseases.
