Regional Agricultural Research Station, Lam, Guntur-522 034, Andhra Pradesh.
Two foliar applications of either carbendazim or thiophanate (0.1%) followed by a combination of carbendazim + tridemorph or thiophanate + tridemorph (0.1%) at fortnightly interval, were found effective in controlling powdery mildew, caused by Erysiphe polygoni Dc and leaf spot caused by Cercospora cruenta Sacc. on blackgram with reduced disease incidence and the grain yield was increased by 7.77 Q/ha. over the untreated check. Maximum net returns were realised from the treatments that received carbendazim (Rs.4072/ha) and thiophanate (Rs. 3516/ha) when used singularly as compared to the combination treatments. The cost benefit ratios were 1:7.9 with carbendazim and 1:6.7 with thiophanate.
