Evaluation of methanolic leaf and bark extracts of Syzygium cumini against Ascochyta rabiei

Laboratory bioassays were carried out to evaluate antifungal activity of different parts of Sizygium cumin (L.) Skeels against chickpea (Cicer arietinum L.) blight pathogen Ascochyta rabiei (Pass.) Lab. Dried and thoroughly crushed leaf, stem-bark and root-bark of the test plant species were extracted in methanol for two weeks. After evaporation of the solvent on a rotary evaporator, different concentrations of methanolic extract viz. 0.5, 1.0, 1.5, ..., 4.0% were prepared by dissolving the material first in dimethyl sulphoxide (DMSO) and then in water. Negative control was without any extract or DMSO while positive control contained the same quantity of DMSO as was present in different concentrations of the extracts. In general, all the concentrations of the three types of methanolic extracts significantly reduced (P≤0.05) fungal biomass to variable extents. The highest antifungal activity was observed due to leaf extract where 23–49% and 20–47% decrease in biomass of A. rabiei was recorded over negative and positive control treatments, respectively. Different concentrations of stem-bark extract reduced fungal biomass by 15–23% and 12–20%, and that of root-bark extract reduced fungal biomass by 10–18% and 6–15% over negative and positive control treatments, respectively. This study concludes that methanolic leaf extract of S. cumini possess remarkable antifungal potential against A. rabiei.