Field Efficacy of Fungicides and Bio-Botanicals against Late Blight Disease of Potato

Potato (Solanum tuberosum l.) is one of the most important Solanaceous vegetable crops throughout the world, and a staple food in many parts of the world. Late blight caused by Phytophthora infestans (Mont.) de Bary is a serious disease, affects all parts of potato viz. leave, stem and tubers. The field experiments were conducted at Benuria, Birbhum during Rabi season of 2015-16 and 2016-17 under Red and Lateritic Agro-climatic Zone of West Bengal. The experiments were conducted to find out the effect of fungicides and bio-botanicals against late blight of potato (cv. Kufri Jyoti). It was revealed from the experiment that Ethaboxam 40% SC@1.33 ml/l appeared highly effective. Ethaboxam 40% SC@1.0 ml/l, Ethaboxam 40% SC@0.88ml/l, Ethaboxam 40%SC@0.75 ml/l were reduced the disease incidence successfully. FolioGold (Chlorothalonil 33% + Metalaxyl 3.3%SC), Ishaan (Chlorothalonil 75% WP) and Trichosol (Trichoderma viride) were also efficacious. Trichosol recorded less effective than other treatments. Botanical based treatments were non-effective. Glossiness of the tuber was measured on harvested tubers observing its colour and luster, and graded as more glossy, glossy, less glossy and non-glossy. Indofil M-45, FolioGold, Ishaan and Trichosol produced more glossy tubers while Ethaboxam and other botanical based treatments produced glossy tubers. Less glossy tubers were counted in untreated control.