Plant Disease Research

In Himachal Pradesh, several diseases are responsible for causing serious losses to the forage cowpea crop. Leaf spot (Cercospora canescens) and powdery mildew (Erysiphe polygoni) are important diseases of cowpea. For the management of these diseases, comparative efficacy of a new molecule of fungicide i.e. Nativo 75 WG (trifloxystrobin 25% +tebuconazole 50%) at different concentrations along with other recommended fungicides was evaluated during kharif 2014 and 2015. Two sprays at 10 days interval of Nativo 75 WG at 350 g/ha were significantly effective in controlling both the diseases i.e. leaf spot and powdery mildew and gave 77.1 and 67.2 percent disease control with a maximum average increase in the grain yield i.e. 20.2 and 19.5 per cent, respectively over the check. This treatment also proved better than other evaluated fungicides. Individually, tebuconazole 250 EC was found more effective as compared to trifloxystrobin 50WG against both diseases. sulphur 80% WG and mancozeb 75% WP were found less effective as compared to tested molecule (Nativo 75 WG (trifloxystrobin 25% +tebuconazole 50%) for the management of leaf spot and powdery mildew of cowpea.