Abstract

Ageratum conyzoides L. is potential allelopathic weed very useful for its antifungal and antimicrobial activity. Being environmentally safe and friendly, it has the potential to substitute synthetic fungicides. The current study, therefore, was designed to evaluate the in vitro efficacy of aqueous methanolic and n-hexane extracts of A. conyzoidesagainst the pathogenic fungi, Fusarium solani Mart. (Sacc.), isolated from roots of egg plant (Solanum melongena). The target fungus was exposed to various concentrations (2, 4 and 6% w/v) of aqueous, methanolic and n-hexane extracts of Inflorescence, leaf, stem and root. All the employed concentrations of extracts of four plant parts significantly suppressed the growth of the target fungal pathogen. The n-hexane extracts of leaf and inflorescence caused highly significant reduction of 84% in growth of F. solani followed by stem and root extracts which caused which caused 80% and 72% reduction in growth, respectively. The same pattern in growth reduction was observed in methanolic and aqueous extracts. Among the four parts of the tested weed, different concentrations of the methanolic extract of leaf were found to be highly effective in controlling target fungal species resulting in up to 78% reduction in fungal biomass over control followed by inflorescence (74% reduction), stem (63% reduction) and root (59% reduction) at highest used concentration. In case of aqueous extracts, the maximum reduction was observed in leaf extract (72%) followed by inflorescence, stem and root, respectively.

Key words: Ageratum conyzoides, aqueous extract, Fusarium solani, n-hexane extract, methanolic extract.