Management of Rhizoctonia solani Kühn causal agent of web blight of soybean under in vitro condition

Abstract

In the present study, the management of Rhizoctonia solani Kuhn causal agent of web blight of soybean under in vitro condition is discussed. One of the techniques employed for the in vitro management of the pathogen were by using eight plant leaf extracts i.e. Ashoka (Saraca asoca), Neem (Azadirachta indica), Aloe vera (Aloe barbadensis), Onion (Allium cepa), Tulsi (Ocimum tenuiflorum), China rose(Hibiscus rosa-sinensis), Parthenium(Parthenium hysterophorus), Calotropis (Calotropis procera). The highest percent inhibition of R. solani over control was observed in extract of Ashoka. Second method was of using five fungicides viz., Contaf (Hexaconazole 5%SC), Saaf (Carbendazim 12%+ Mancozeb 63%WP), Tilt (Propiconazole 25%EC), Taspa (Propiconazole 13%+Difenconazole 13.9% SC) and Nativo (Trifloxystrobin 50%+Tebuconazole 25% WG) against R. solani under in vitro condition by poison food technique.Saaf was found to be the most effective as no mycelial growth was observed. Third method was Dual culture technique using Trichoderma viride which exhibited significant inhibition of R. solani as compared to control. The percent inhibition was converted to 1-5 scale which indicated the reaction type. In the experiment, the reaction type was found to belong to 2 scale i.e. Trichoderma overgrew at least two thirds of the medium surface.