Abstract

Recent adaptation of yellow rust (Pst) to warmer climates poses an increasing threat to wheat production. Therefore, wheat needs to be treated with fungicide to protect the flag leaf and save severe yield losses. A field experiment was conducted during 2014-15 and 2015-16 to compare the efficacy of fungicides and spray timing for reducing yellow rust yield losses in wheat. Both years these trials were conducted at two yellow rust hot spot locations i.e., Cereal Crops Research Institute (CCRI) Nowshera and Crop Diseases Research Institute (CDRI) Islamabad.

Three fungicides i.e., Folicur (tebuconazole) @300 mL/ha, Nativo (tebuconazole + trifloxystrobin) @300 g/ha and Tilt (propiconazole) @ 500 mL/ha were used in this study. In a double split plot design with two replications, one set of plots were treated with single spray at ZS-3 (stem elongation and jointing) stage and other set of plots were treated with two sprays (first at ZS-3 and second at ZS-4.3 to 5.5). All three fungicides significantly (P=0.05) reduced wheat yield losses as compared to control plots and returned a significant profit as well. However, there were no significant efficacy differences among these fungicides, nor in the spray timing/doses. By gaining 2.36 t/ha yield and 126.78 US $/ha marginal return, Folicur proved to be best choice against yellow rust. There was no significant differences for grain yield efficacy between the two studied spray timings, however, with 113.53 US $/ha marginal return single spray at ZS-3 (stem elongation and jointing) seemed to be appropriate stage for reducing cost effective wheat yield losses.