Sustainable Approaches for Managing Alternaria Blight in Mustard (Brassica juncea L.) Caused by Alternaria brassicae (Berk.) Sacc.

Brassica juncea, also known as Indian mustard, is a globally used oilseed, vegetable, and condiment. Alternaria brassicae, a filamentous fungus, causes Alternaria black spot, affecting crop productivity. This research endeavours to investigate environmentally sustainable methods for managing the Alternaria blight on mustard. The experiment was analyzed in randomized block design (RBD) with three replications in a plot size 2x1 m2. The field experiment was conducted at the research plot in the Central Research Field, SHUATS, Prayagraj, U.P. during Rabi season 2022-2023 to test the effect of Trichoderma viride, Pseudomonas fluorescens, eucalyptus oil, neem leaf extract, salicylic acid, and Ascophyllum nodosum on Alternaria blight of mustard (Brassica juncea L.) caused by Alternaria brassicae (Berk.) Sacc. Treatments included seed treatment and foliar applications optimized from prior laboratory trials. Parameters like disease intensity and plant growth were assessed, and data were statistically analyzed. Among the treatments, Trichoderma viride @ 10 g/L was the most effective followed by salicylic acid. The seed treatment and foliar spray of T. viride @ 10g/L thrice at 15-day intervals significantly reduced disease intensity on leaves (37.20%) and pods (18.73%), AUDPC (1245) and significantly increased the yield (1.631 t/ha), and cost-benefit ratio (2.37). However, the maximum height of the plant was recorded in Ascophyllum nodosum (189cm). The current experiment proved that, without using any chemicals, the management of Alternaria blight disease in mustard can be profoundly possible through the use of different bio-agents, essential oils, botanicals, and elicitors.