Management of anthracnose disease of banana caused by Colletotrichum musae using plant extracts

Plant extracts for the control of plant disease are emerging as alternatives to conventional fungicides as they are generally safe to humans and environmentally friendly. Extracts of 50 plants were screened in vitro against the fungal banana pathogen Colletotrichum musae. Those of Solanum torvum, Jatropha curcas and Emblica officinalis inhibited mycelial growth of C. musae. S. torvum extract at 25 and 50% conc. (w/v) completely inhibited growth of C musae while those of E. officinalis and J glandulifera restricted growth to 7.6 mm day(-1) at 50% concentration. The same extracts were tested in vivo at room temperature (28 +/- 2degreesC) and in cool store (13.5degreesC) against anthracnose disease on the three banana varieties Robusta (AAA), Rasthali (AAB) and Ney Poovan (AB), S. torvum extract was found to be very effective in reducing the incidence of the disease, better than a standard treatment with the fungicide benomyl (0.1%). The extracts also significantly increased the shelf life of bananas, particularly their green life, in all the cultivars tested, with S. torvum extract the best. Shelf life was extended by 16-20 d over the control; in most cases the extension was significantly longer than that afforded by benomyl. Hence, plant extracts, particularly of S. torvum, can be used not only for the management of anthracnose disease but for increasing the shelf life of bananas.