Effect of Trichoderma viride and Botanical Extracts on Alternaria Leaf Spot Disease of Cabbage (Brassica oleraceae var. capitata L.)

Cabbage is most important vegetable crop. This vegetable has leaf spot disease from bacteria, fugal and virus. Therefore, the present investigation on “Effect of Trichoderma viride and botanical extracts on alternaria leaf spot disease of cabbage (Brassica oleraceae var. capitata L.)” was carried out in Rabi-2023-24 under field conditions. The effect of treatments were evaluated on different growth parameters, disease intensity (%), yield and cost benefit ratio of cabbage.

The significantly effective in reducing disease intensity (%) was obtained in combine treatment of Trichoderma viride with Neem leaf extract at 45 days after transplanting (17.27 %), 60 days after transplanting (22.66 %) and 75 days after transplanting (27.34 %), with highest C:B ratio (1:2.32) followed by Trichoderma viride with Eucalyptus leaf extract at 45 (17.87 %), 60 days after transplanting (23.31 %) and 75 days after transplanting (28.72 %), with C:B ratio (1:2.13) and least disease intensity was recorded in Trichoderma viride with Garlic bulb extract at 45 days after transplanting (19.54 %), 60 days after transplanting (25.67 %) and 75 days after transplanting (33.64 %), with least C:B ratio (1:1.21) as compared to control at 45 days after transplanting (23.35 %), 60 days after transplanting (31.33 %) and 75 days after transplanting (45.38 %), with lowest C:B ratio (1:0.86).

The treatment of Trichoderma viride with Neem leaf extract resulted in maximum number of leaves at 45 days after transplanting (14.20), 60 days after transplanting (25.47) and 75 days after transplanting (36.27), head diameter (14.20 cm), head weight (0.69 kg) with highest yield (25.45 t/ha) followed by Trichoderma viride with Eucalyptus leaf extract at 45 days after transplanting (13.13), 60 days after transplanting (23.33) and 75 days after transplanting (33.73), head diameter (13.05 cm), head weight (0.65 kg) with yield (24.03 t/ha) and least number of leaves was recorded in Trichoderma viride with Garlic bulb extract at 45 days after transplanting (8.93), 60 days after transplanting (14.80) and 75 days after transplanting (23.33), head diameter (8.20 cm), head weight (0.49 kg) with least yield (17.99 t/ha) as compared to control at 45 days after transplanting (7.53), 60 days after transplanting (12.00) and 75 days after transplanting (20.73), minimum head diameter (7.05 cm), head weight (0.38 kg) with lowest yield (14.22 t/ha).