Evaluation of Antifungal Properties of Botanical Extracts in the Management of Common Spoilage Fungi of Rice ( Oryza sativa L.)

Abstract

Rice is the staple food in Liberia and cultivated throughout the country. Spoilage fungi are responsible for great losses during storage and this threatens the country's food security. This study sought to evaluate the suitability of plant extracts as alternative management option against this problem. Rice samples were obtained from four main rice growing counties (Nimba, Montserrado, Bong' and Lofa) and taken to the University of Eldoret seed science lab for the isolation of fungal contaminants. Randomly selected rice grains were surface sterilized using Sodium hypochlorite and placed on Potato dextrose agar (PDA) to isolate spoilage fungi. Botanical aqueous extracts were prepared from common bean ash, neem, ginger, chilli, and garlic. Six fungi were isolated from the rice seeds (arranged in the order of prevalence; Aspergillus niger, A. flavus, Penicillium sp, Pyricularia oryzae, and Fusarium sp). The bean ash was the most effective botanical extract achieving 100% inhibition for all the fungi tested except Fusarium sp. Fusarium sp was the most resistant fungal pathogen with the best inhibition towards it imparted by the synthetic fungicide (tebuconazole) at 56% inhibition. All the botanical extracts used in the study should be further explored as possible sources of more sustainable disease management.