Effects of Bio-Agents and Selected Botanicals on Alternaria Leaf Spot Caused by Alternaria alternata (Fr.) Keissler in Broccoli (Brassica oleracea var. italica L.)

A field experiment was conducted at the research plot of the Department of Plant Pathology, SHUATS, Prayagraj, Uttar Pradesh in Rabi season of 2023 to evaluate eight treatments viz., T1– (Pseudomonas fluorescens (S.T) @ 2%, T2– Trichoderma viride (S.T) @ 2%, T3– Pseudomonas fluorescens (S.T) @ 2% + Ocimum sanctum (F.S) @ 10 %, T4- Trichoderma viride (S.T) @ 2 % + Allium sativum (F.S) @10%, T5– Trichoderma viride (S.T) @ 2% + Ocimum sanctum (F.S) @ 10%, T6 - Pseudomonas fluorescens (S.T) @ 2% + Allium sativum (F.S) @ 10 %, T7 – Carbendazim @ 0.1% (F.S) (treated control) and control T0 (untreated control) with three replications in Randomized Block Design (RBD) for management of alternaria leaf spot of broccoli. Study on disease intensity of alternaria leaf spot of broccoli in field conditions revealed that the Minimum percent disease intensity (%) was recorded in T4 – 28.17% Trichoderma viride @ 2% (S.T) combined with Allium sativum @ 10% (F.S) as compared with the untreated control T0 – 38.31 % and treated check T7 – 24.42 % (Carbendazim @ 0.1% (F.S). PDI recorded in broccoli with maximum cost benefit ratio per treatment was recorded 1:1.915 in T4 - Trichoderma viride @ 2% (S.T) combined with Allium sativum @ 10% (F.S) in broccoli.