Efficacy of different advanced fungicides against late blight of potato incited by Phytophthora infestans in southern Karnataka

Late blight caused by oomycete Phytophthora infestans (Mont.) de Bary has historically been an important dreaded disease of potato across the world. The late blight disease caused widespread crop failures throughout southern Karnataka including Hassan, Chikamagalore, Kolar, Chickaballapura and Bengaluru rural districts. The epidemics of late blight in southern Karnataka have been associated with the emergence of new strain of Phytophthora infestans and in which Metalaxyl resistance was found. With an objective of identification of suitable fungicide formulation, concentration and its interval to manage late blight of potato in southern Karnataka. An experiment was conducted during Kharif season for three consecutive years from 2014 to 2016 at Horticulture Research and Extension Station, Somanahallikaval, Hassan, Karnataka. The pooled data of three years indicated that among nine different fungicidal treatments, least per cent disease intensity of 19.44 was observed in the treatment of Femoxidone + Cymoxanil @ 0.1 per cent, which resulted in highest marketable tuber yield of 17.77 t/ha with lowest blighted tubers of 0.42 t/ha followed by treatment with Ametoctradin + Dimethomorph @ 0.1 per cent, wherein 21.32 per cent disease intensity with marketable tuber yield of 14.27 t/ha and 0.57 t/ha of blighted tubers were documented and it was found on par with treatment of Fenamidone + Mancozeb @ 0.3 per cent with 22.85 per cent disease intensity and marketable tuber yield of 13.78 t/ha with 0.65 t/ha of late blight affected tubers were documented. Further in control highest disease intensity of 57.66 per cent with lowest marketable tuber yield of 6.79 t/ha and highest blighted tubers of 1.22 t/ha were recorded.