Integrated Effect of Trichoderma harzianum with Selected Botanicals Extracts on Alternaria Leaf Spot of Broccoli (Brassica oleracea var. italica) Caused by Alternaria brassicae (Berk.) Sacc.

Broccoli (Brassicae oleracea var. italica) is an important cole crop vegetable, belong to family Brassicaceae. Alternaria leaf spot caused by Alternaria brassicae is one of the serious diseases in broccoli. In vitro and in vivo experiment were conducted at the research plot of the Department of Plant Pathology, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj, Uttar Pradesh in Rabi season 2023-2024, to evaluate Trichoderma harzianum and botanicals on Alternaria leaf spot of broccoli caused by A.brassicae. In vitro condition, five botanical extracts were taken at the concentration 10% and T. harzianum at 10% and Mancozeb at 0.2% (treated check). In vivo condition, eight treatments were taken and all seedlings were treated with T. harzianum at 10%, Mancozeb at 0.2% and foliar spray of botanical extracts @10% except T0– control (untreated check) and (treated check). In vitro condition, among the treatments Neem leaf extract at 10% were observed effective in the per cent disease inhibition (%) (79.77) followed by Eucalyptus leaf extract at 10% (75.69). Among the treatments, under In vivo condition, T3- T. harzianum (S.T.) + Neem leaf extract (F.S.) was observed minimum disease intensity (16.59, 19.85 and 23.28 %) at 45,60 and 75 DAT, respectively. Maximum plant height (9.78, 23.84 and 36.66cm) at 30,60 and 90 DAT, number of leaves per plant (9.36, 17.26 and 28.00), head weight (0.38 kg) and yield (9.68 t/ha) were found in T3- T. harzianum (S.T.) and Neem leaf extract (F.S.) when compared to treated T7- mancozeb (treated check) and T0- Control (untreated check).