Antifungal activity of aqueous and organic solvent extracts of allelopathic trees against Ascochyta rabiei

Antifungal properties of aqueous, n-hexane and ethanol extracts of leaf, fruit, root bark and stem bark of Eucalyptus citriodora Hook and Alstonia scholaris (L.) R. Br. were investigated against Ascochyta rabiei (Pass.) Lab., [casual organism of blight disease in chickpea (Cicer arietinum L.)]. Effects of 1, 2, …5% (w/v) extracts of different parts of the two test tree species were studied against in vitro radial growth of test fungal species on 2% malt extract agar medium amended with chickpea power @ 1.0 g 100 ml⁻¹ of the medium. Aqueous leaf and root bark extracts of E. citriodora fruit at 1–5% concentrations, reduced the colony diameter of A. rabiei by 25–38% and 22–41%, respectively. Similarly ethanol extracts of fruit and root bark of E. citriodora also reduced colony diameter of test fungal species by 13–25% and 16–42%, respectively. None of the aqueous or organic solvent extracts of A. scholaris exhibited antifungal activity against the target fungal pathogen.