Effect of seed treatment and foliar spray on leaf blight of fodder oat in Punjab

Pyrenophora avenae Ito & Kurib. is an important fungal pathogen of leaf blight (HLB) causing significant fodder and grain yield losses in oat. The effect of fungicides (carboxin + thiram, tebuconazole, carbendazim, mancozeb and propiconazole), plant extracts (Melia azedarach, Murraya koenigii and Azadirachta indica) and biocontrol agents (Trichoderma harzianum and T. viride) was evaluated in 2016-17 and 2017-18 for HLB management in oats. The seed infection was almost double in 2017-18 (19.6%) as compared to 2016-17 (8.8%). Greater mean reduction in disease severity was provided by propiconazole spray (54.28%) followed by tebuconazole (46.22%). Foliar spray of propiconazole provided 23.47 and 26.75% increase in green fodder yield in 2016-17 and 2017-18 respectively as compared to control. Foliar applications increased grain yield by a factor of 13-50% in 2016-17 and 3-44% in 2017-18 and seed treatments increased grain yield by 12-39%. Aqueous extract of M. azedarach and A. indica significantly reduced the leaf blight severity by 57.85 and 52.78% respectively with increase in green fodder yield, grain yield and thousand kernel weight. Therefore, seed treatment and foliar application of fungicides or aqueous plant extracts were equally effective against leaf blight and showed increase in green fodder and grain yields.