Abstract

The antifungal activity of allelochemicals extracted from rice straw on the radial growth rate and the activity of some hydrolyzing enzymes of Aspergillus flavus, Alternaria alternata and Botrytis cinerea were studied in vitro. Five different concentrations (2, 4, 6, 8 and 10%, w/v) of water, methanol and acetone extracts of rice straw were tested. All extracts significantly (P<0.05) inhibited the radial growth rate and protease, carboxymethyl cellulase (CMCase) and amylase activities of the tested fungal species. The most potent solvent was methanol. The present study suggests that rice straw extract had antifungal properties, thus it can be used as a natural alternative approach to synthetic fungicide.

Key words: Rice straw, allelochemicals, antifungal, Aspergillus flavus, Alternaria alternata, Botrytis cinerea, amylase, protease, carboxymethyl cellulase.