Survey for the Alternaria Blight of Sunflower in Southern Transition Zone of Karnataka

A roving survey was conducted to assess the incidence of alternaria blight of sunflower caused by A. helianthi in southern transition zone of Karnataka during kharif 2013–14. The disease severity was ranging from 31.11 to 51.11 per cent. Among the sunflower growing districts the highest mean disease severity was recorded in Chitradurga district (43.75%) followed by Davanagere (39.25%), Shimoga (38.25%) and Chikmaglur (36.91%). However the lowest severity was observed in Hassan (36.85%) district. The congenial weather conditions like heavy rainfall, higher relative humidity and moderate temperatures might have helped in building up of high disease pressure in Chitradurga and Davanagere districts.