Management of powdery mildew of wheat through chemicals

Powdery mildew of wheat (Erysiphe graminis f.sp. tritici) is a potential threat, inflicting considerable losses in foot hills and some pockets in Himachal Pradesh with changing agro climatic conditions over the years. Since, none of the recommended varieties is resistant to this disease and moreover, resistance sources are not available in aestivum wheat so the management with chemicals remains the only alternative to tackle it. Keeping in view these facts, a replicated field trial on the management of powdery mildew was conducted during rabi 2008–09, 2009–10 and 2010–11 by using a susceptible variety PBW 343 and five fungicides viz. Tilt 25 EC (0.1%), Contaf 5 EC (0.1%), Bavistin 50 WP (0.1%), Karathane 48 EC (0.05, 0.1%) and Sulfex 80 WP (0.3%). The trial consisted of 12 treatments i.e. single sprays of four systemic fungicides at the initiation of the disease, two sprays of these fungicides at 15 days interval and three sprays of Sulfex, a non systemic fungicide at 10 days interval and a check without spray. The results indicated that two sprays of Tilt (0.1%) gave complete control whereas Contaf (0.1%) gave cent percent and 96% control of powdery mildew during rabi 2008–09 and 2010-11respectively. During rabi 2009–10, two sprays of the same fungicides gave 27and 32 percent control respectively. Rest of the treatments, were statistically at par except Sulfex (0.3%) which was least effective in controlling the disease. The disease was found to cause losses from 23 to 33 percent during these rabi seasons.