EVALUATION OF TRANSLAMINAR FUNGICIDESAND THEIR TANK MIXED APPLICATION WITH ECONOMICS FOR MANAGEMENT OF LATE BLIGHT OF POTATO (PHYTOPHTHORA INFESTANS) IN SUBTROPICAL PLAINS OF INDIA

Late blight, incited by Phytophthora infestans (Mont.) de Bary is the major disease of potato under the classof foliar diseases. Chemical methods are being used for the effective management of late blight. However, this pathogenis more vulnerable against specific mode of chemicals (systemic fungicides), which may develop resistant. The fieldefficacy of translaminar fungicides and their tank mixed application with economics were evaluated in two differentexperiments for managing late blight of potato during three consecutive years. In first experiment it was observed thatdimethomorph 50%WP @ 0.2% showed least average terminal disease severity (14.54%) with highest disease controlled(84.15%) followed by ametoctradin 27% + dimethomorph 20.27% SC @ 0.2% and cymoxanil 8 + mancozeb 64%WP @ 0.3%.In second experiment, under the tank-mixed application dimethmorph 50%WP @ 0.1% + mancozeb 75%WP @ 0.2% showedless average terminal disease severity (22.67%) with highest disease controlled (75.97%) along with highest tuber yield(40.70 t/ha) and highest B:C ratio (2.16) followed dimethmorph 50%WP @ 0.1% + chlorothalonil 75% WP @ 0.2%, whichwas statistically significant. These treatments are also least affected by environmental factors like rainfall. These newfungicides and their tank-mixed sprays were found effective for managing the disease and moreover these tank-mixedsprays can be used to avoid development of resistance against pathogen.