Antifungal activity of some plant extracts against phytopathogenic fungi

Abstract

Aqueous and ethanol leaf extracts of Capsicum annuum L. (pepper), Helianthus annuus L. (sunflower), Juglans regia L. (walnut), Sinapis arvensis L. (wild mustard) and Solanum lycopersicum L. (tomato) were evaluated for antifungal activity against five economically important phytopathogenic fungi including Botrytis cinerea Pers.:Fr., Fusarium culmorum (W.G. Smith) Sacc., F. solani (Mart.) Sacc., Macrophomina phaseolina (Tassi) Goidanich and Rhizoctonia solani Kuhn. In general, the antifungal efficacy of ethanol extracts was higher than that of aqueous extracts. The percentage of mycelial growth inhibition ranged from 3.8 to 48.8% and 3.1 to 84.1% for aqueous and ethanol extracts, respectively. Ethanol extract of H. annuus at 10% concentration (w/v) showed the highest antifungal efficacy on mycelial growth of R. solani. The percentage of inhibition in spore germination ranged from 3.3 to 76.2% and 5.6 to 100% for aqueous and ethanol extracts, respectively. Ethanol extracts of H. annuus and S. arvensis at 5% concentration completely inhibited the spore germination and germ tube elongation of B. cinerea and F. culmorum except F. solani, which was the most resistant fungus at all experiments. Aqueous extract of S. arvensis at 10% concentration completely inhibited the mycelial growth of F. culmorum, M. phaseolina and R. solani in soil tests. In addition, soil tests used in this study are original and important to evaluate antifungal activity under conditions close to the natural environment. The results of this study indicate that ethanol and aqueous leaf extracts of tested plants could become natural alternatives to synthetic fungicides for control of tested phytopathogenic fungi.