Somalingappa B. Palled and H.N. Ramesh Babu
Abstract
In the present investigation, different districts of Northern dry zone of Karnataka were closely examined for various major foliar diseases in rain fed and irrigated Bt cotton crop fields. A roving survey was conducted on cultivars field during the crop season in the year 2023-25 and a fixed plot survey on Bt cotton was conducted periodically in research form at Gadag. The diseases were identified based on the development of characteristic disease symptoms on the plant and morphological studies of the associated microorganisms under microscope and were identified as fungal diseases Alternaria blight (Alternaria macrospora Zimm.), Grey (Areolate) mildew (Ramularia areola Atk.), and of the bacterial disease, bacterial blight (Xanthomonas compestris pv. malvacearum (Smith) Dye), The observations on disease severity, stage of the crop, variety and other details were recorded. The percent disease incidence was assessed by recording the number of plants showing disease symptoms and the number of plants examined, where highest incidence of the fungal diseases was recorded. It was also observed that bacterial blight incidence.