Control efficacy and yield response of different fungicides evaluated against anthracnose of green gram

Green gram anthracnose disease caused by Colletotrichum lindemuthianum (Sacc. and Magn.) Briosi and Cavara is known to cause an estimated yield loss of 30-70 per cent under natural field condition. Considering the devastating nature of the disease an effort was undertaken to assess the fungicidal efficacy to manage the anthracnose disease under field conditions. Eight different fungicides were evaluated against anthracnose disease during the year 2019-2021. The results on the management of anthracnose disease were recorded at regular intervals and two foliar applications of ready-mix fungicide carbendazim 25% + mancozeb 50% WS (0.15%) applied at 15 days interval exhibited minimum mean per cent disease intensity of 33.91% (pooled mean). Disease reduction by use of non systemic fungicides was relatively low and propineb 70% WP treated plots recorded highest disease incidence of 45.84 per cent. Similarly, propineb 70% WP treated plots yielded lowest seed yield (870 kg/ha) in comparison to carbendazim 25% + mancozeb 50% WS (0.15%) treated plots which recorded 65.71 per cent increased in yield (1226 kg/ha) over control. The effect of anthracnose disease on yield of green gram was significant as untreated control produced only 740 kg/ha seed yield. The correlation coefficient (r) and coefficient of determination (R2) calculated for per cent disease intensity (PDI) and seed yield for the three consecutive years and pooled mean was r =-0.8251,-0.7926,-0.8395 and-0.8225 and R2 = 0.6807, 0.6283, 0.7047 and 0.6765, respectively which showed a strong negative correlation with a high goodness of fit. The linear regression equation obtained was y = - 9.8887x + 1436.2 for pooled mean data of three years. Similarly, the plots treated with carbendazim 25% + mancozeb 50% WS had obtained the maximum incremental cost benefit ratio (ICBR) (1:5.22) and lowest ICBR was recorded by fungicide myclobutanil 10% WP (1:0.20).