Evaluation of antifungal activity of methanolic extracts of Dicanthium annulatum for the management of Macrophomina phaseolina

The present study was carried out to assess the antifungal potential of an allelopathic grass Dicanthium annulatum (Forssk.) Stapf. against Macrophomina phaseolina (Tassi) Goid. isolated from cowpea [Vigna unguiculata (L.) Walp.] plants suffering from charcoal rot disease. Different parts of this grass namely shoot, root and inflorescence were extracted in methanol. After evaporation of methanol, different concentrations (0, 0.5, 1.0, …, 3.0 g ml-1) of the extracts were prepared and their antifungal activity was studied. In general, extracts of all the three parts exhibited antifungal activity. However, a marked variation in antifungal activity among the extracts of different parts of the test grass was observed. There was 7 to 51%, 29 to 71% and 33 to 81% reduction in fungal biomass due to different concentrations of shoot, root and inflorescence extracts of D. annulatum, respectively.   Key words: Antifungal activity, charcoal rot, Dicanthium annulatum, Macrophomina phaseolina, methanolic extracts.