Development of fungicides spray schedule to manage the late blight of potato in north eastern Himalayan region of India

Abstract

Late blight of potato is a major disease of potato in north eastern Himalayan region of India. An experiment was carried out at Central Potato Research Station, Shillong, Meghalaya (India) during the years 2012, 2013 and 2014. Different fungicide treatments combinations were applied in potato crop at 7 days intervals. Pooled data of disease severity in cultivar Kufri Jyoti showed that first prophylactic spray with mancozeb (0.2%), second spray with dimethomorph (0.2%) + mancozeb (0.3%) and third spray with mancozeb (0.2%) was found significantly superior to reduce blight severity (39.44%) after 35 days after appearance of disease. Other fungicide treatments combinations (contact and systemic) were found significant as compared to control in Kufri Jyoti. In Pooled analysis, highest yield (35.51 t/ha) was recorded in treatment (T5; mancozeb, diemthomorph + mancozeb, mancozeb) of Kufri Jyoti. Kufri Giridhari did not respond to the fungicides significantly. Analysis of variance (ANOVA) of yield revealed that interaction between fungicides and varieties were found significant during the 2013 and 2014. All the three environments i.e. years form a single mega-environment which showed that there were significant differences in environments but not extreme differences and the order of the treatments was same across all the environments. In conclusion, newly developed fungicides spray schedule will be helpful to manage the late blight of potato and increase the potato yield in north eastern Himalayan region of India.