MANAGEMENT OF CAUSAL ORGANISM OF COLLAR ROT OF BELL PEPPER (SCLEROTIUM ROLFSII) BY ORGANIC SOLVENTS EXTRACTS OF DATURA METEL FRUIT

Abstract

Present study was undertaken to investigate the antifungal potential of methanolic fruit extract of Datura metel L. (Syn. Datura alba Nees.) and its various solvent fractions against Sclerotium rolfsii Sacc., the cause of devastating collar rot disease of bell pepper (Capsicum annuum L.). In an in vitro study, conducted in 250-mL conical flasks, different concentrations of methanolic fruit extract (0.5, 1.0, 1.5, …, 4.0%) significantly reduced the fungal biomass by 69–94%. Methanolic fruit extract was successively partitioned among n-hexane, chloroform, ethyl acetate and n-butanol in order of increasing polarity. Different concentrations (3.125, 6.25, 12.50, 25, 50, 100, 200 mg mL-1) of these fractions were used against the test pathogen. Pronounced variability in antifungal activity was recorded with respect to extracting solvent and the extract concentration. Chloroform fraction exhibited the highest antifungal activity resulting in 36–50% reduction due to different concentrations. Ethyl acetate was found comparatively less inhibitory where only 8–35% reduction in fungal biomass was observed due to different concentrations of the extract. n-hexane, n-butanol and aqueous fractions generally stimulated the fungal growth to variable extents. The present study concludes that S. rolfsii can be controlled by natural antifungal compounds in chloroform fraction of methanolic fruit extract of D. metel.