Economically viable fungicidal management for powdery mildew of wheat

Ten fungicides were evaluated for the management of wheat powdery mildew (PM) using susceptible variety HS 240 at hot spot locations viz., Palampur, Dhaulakuan and Malan during the cropping season 2016–17 and 2017–18. All the treatments resulted in significantly less disease intensity (%) and higher yield (q/ha) as compared with the no spray control plots during both the cropping seasons and at all the locations. The least mean disease intensity was recorded in two foliar sprays of tebuconazole (84.84%) followed by propiconazole @ 0.1% (78.33 per cent) over the no sprayed control. Maximum mean grain yield (50.5 q/ha) was recorded in two foliar sprays (FS) of azoxystrobin @ 0.1%. It was 12.15 q/ha i.e., 24.06 per cent higher over the no spray control (38.35 q/ha) with corresponding net profit of Rs. 10,117 and 1:2.30 cost: benefit ratio. It was followed by 48.41, 47.94, 47.98 and 45.28 q/ha yield in tebuconazole + trifloxystrobin @ 0.05%, tebuconazole, difenoconazole and hexaconazole + captan @ 0.1% showing mean increase in yield by 10.06, 9.59, 9.63 and 8.73 q/ha i.e., 20.78, 20.01, 20.08 and 23.87 per cent over the no spray control. These treatments resulted in net profit of Rs. 12,313, 12,969, 10,596 and 12,866 /ha with cost: benefit ratio of 1:2.75, 1:3.36, 1: 2.33 and 1:4.27, respectively. According to Tukey’s post hoc test the least per cent disease intensity was recorded at Malan and all the treatments resulted in significantly reduced disease intensity (%) and increase in yield (q/ha) as compared to no spray control. The interaction effects of locations and treatments were non-significant for both the per cent disease intensity and yield. North Western Plain Zone (NWPZ) and North Hill Zone (NHZ) are epidemiological important areas for PM and most of the varieties recommended for these area are susceptible. Effective fungicides and fungicidal mixtures evaluated in the present studies, are commercially available and may be judiciously used especially in the high value seed production plots to avoid yield losses. © 2022, Indian Phytopathological Society.