Forecast and Need Based Fungicide Application for Effective Management of Late Blight of Potato
Abstract
Late blight caused by Phytophthora infestans (Mont) de Bary is one of the most dreaded diseases of potato worldwide and cause significant losses in production. It affects both potato foliage in the field and tubers in storage. A number of management techniques for late blight have been developed and used throughout the world. Effective control of this disease requires an integrated disease management approach. Fungicides alone can't control late blight effectively, but should be used as a tool in an integrated management. In present studies, weather forecast based targeted application of fungicides with recommended cultural practices (use of healthy seed, seed treatment, proper spacing and hilling etc.) were used for effective management of the disease. Preventive fungicide applications were given, by identifying conducive period for disease development using local weather forecast. Effective management of disease i.e. 92.17 and 90.93 per cent during 2014 and 2015, respectively was achieved in demonstration trials by following prophylactic spray of mancozeb, sprays of cymoxanil 8% + mancozeb 64%, just after disease appearance, followed by need based sprays of mancozeb and cymoxanil 8% + mancozeb 64% at 10 days interval. contrary to this, in control i.e. farmers’ practice, disease incidence of 95.83 and 96.94 per cent was recorded during 2014 and 2015, respectively, as farmers sprayed fungicides indiscriminately, only after disease appearance.
