Need-based application of fungicides for management of late blight in potato

Data generated on need-based application of fungicides for the management of potato late blight revealed that ‘BLITECAST’ is not suitable for applying need-based fungicides under Shimla conditions. CPRl's recommendations based on field severity value on fungicides applications viz. i) 4 sprays of mancozeb at 8–10 days interval or ii) 2 sprays of mancozeb and one spray of metalaxyl + mancozeb were more accurate. A minimum of 15 severity value accumulation was required for applying mancozeb whereas for applying metalaxyl + mancozeb a minimum of 32 severity values were required. This information is expected to be useful for developing a need-based fungicide schedule by integrating the disease forecasting system already developed for the region.