Antifungal Activity of Plant Extracts in Different Solvents against Rhizoctonia solani Causing Sheath Blight disease in Rice

Abstract

Sheath blight of rice caused by Rhizoctonia solani (R. solani) leads to significant yield losses under severe disease conditions. This study investigates the efficacy of various aqueous and ethanol plant extracts against the mycelial growth and sclerotial production of R. solani under In vitro condition and sheath blight disease in rice under polyhouse condition. Among the aqueous extracts, Datura stramonium showed the highest efficacy, reducing mycelial growth from 13.17 mm at 20% concentration to 3.34 mm at 50%, with 85.37% to 96.29% inhibition. Cannabis sp. and Calotropis gigantean also exhibited strong antifungal properties, while Aegle marmelos, Aloe barbadensis and Azadirachta indica showed moderate effectiveness. Nerium oleander was the least effective. Ethanol extracts of Aegle marmelos, Calotropis gigantean, and Datura stramonium completely inhibited mycelial growth at all concentrations, with Azadirachta indica, Cannabis sp. and Aloe barbadensis also demonstrating high efficacy. Datura stramonium aqueous extract was the most effective in reducing sclerotium production, while ethanol extracts of Aegle marmelos, Calotropis gigantean, Datura stramonium, and Azadirachta indica completely inhibited it. In polyhouse conditions, aqueous and ethanol extracts of Datura stramonium and Cannabis sp. were the most effective in reducing rice sheath blight severity, with Datura stramonium reducing severity to 10.96% and 7.67%, respectively and Cannabis sp. to 11.78% and 8.25%. Calotropis gigantean and Aegle marmelos also showed notable effectiveness. These findings highlight the potential of Datura stramonium and Cannabis sp. as eco-friendly agents for managing R. solani and rice sheath blight disease.