Effect of organic amendments with Trichoderma spp. against Alternaria leaf spot (Alternaria brassicicola) of cabbage (Brassica oleracea var. capitata L.)

Cabbage is one of the most popular and widely grown vegetables in the world and is affected by various fungal and bacterial diseases and among them Alternaria is prevalent in all the cabbage growing states, which affects its production and quality of produce. So, the research was carried out for the management of Alternaria leaf spot of cabbage using organic amendments and bioagent. The research was conducted during the Rabi season 2023-2024 at the Central Research Field, Department of Plant Pathology, SHUATS, Prayagraj, U.P. The effect of Trichoderma harzianum and organic amendments i.e. neem cake and vermicompost both in individually and in combination were studied under field condition against Alternaria leaf spot of cabbage caused by Alternaria brassicicola. Soil application of Trichoderma harzianum @ 0.5 g/m2 along with neem cake @ 50 g/m2 and vermicompost @ 1 kg/m2 recorded the minimum disease intensity (24.25%) and maximum number of leaves (14.87), head weight (1.04 kg), head diameter (13.07 cm), yield (33.96 t/ha) and cost benefit ratio (1:3.15) as compared to other treatments including control.