DEVELOPMENT OF EFFECTIVE SPRAY SCHEDULE FOR THE MANAGEMENT OF LATE BLIGHT OF POTATO IN PLAINS OF WEST BENGAL

Potato J 39 (1): January June, 2012 Late blight of potato caused by Phytophthora infestans is one of the most serious diseases of potato world over. It was first noticed in Darjeeling district in 1883. In the plains, it was first observed during 1898-1900 in Hooghly district of West Bengal. Today, late blight is a recurring feature in plains of West Bengal. It occurs in mild to moderate form every year but occasionally assumes epiphytotic proportions. Yield losses in the plains have been estimated around 10-75% (Dutta, 1979). Several components are available for late bight management. However, only two of them viz. host resistance and use of fungicides hold promise. Since, the pathogen is highly variable and changes itself with a slight change in the environment, the host genotype resistance in most of the varieties is broken within few years of their cultivation. Hence, the only option left is the use of need based effective fungicides for the management of late blight of potato (Singh et al., 2003).