Assessment of yield losses due to stripe rust caused by Puccinia striiformis f. sp. tritici on bread wheat cultivars in Punjab

Abstract

stripe rust caused by P. striiformis Westend f.sp. tritici eriks. is an important and the most damaging disease of wheat, appearing continuously since 2006–07 in sub-mountainous districts of Punjab, and causes enormous yield losses every year. For the effective and economical management of stripe rust, the present study was aimed to determine the extent of losses caused by stripe rust in different wheat cultivars recommended in Punjab and North Western Plains Zone (NWPZ) with different levels of resistance. The experiment was conducted in Randomized Block design in pair treatment (Protected versus unprotected) using systemic fungicide propiconazole (Tilt 25EC) @ 0.1% (200 ml in 200 litres of water/acre) during two crop seasons i.e. 2016–17 and 2017–18 on seven wheat varieties, namely HD 3086 (Resistant), PBW 725 (Resistant), PBW 677, Unnat PBW 343 (PBW 723), PBW 621, HD 2967 and PBW 343 (Susceptible check)). Three sprays of fungicide were given from disease initiation onwards at 15 days interval on the susceptible varieties. no disease was observed in the test varieties under protected conditions and it varied from 0–80S under unprotected conditions. The effect of stripe rust severity on grain yield was significant (P<0.05) between protected and unprotected plots in case of moderately susceptible and susceptible cultivars. in susceptible variety PbW 343, the yield losses were estimated to be 75.1%. the disease parameters were negatively correlated with the yield. The cost benefit ratio implied that maximum net returns were obtained in fungicide treated plots of susceptible varieties followed by moderately susceptible varieties and were negative for resistant cultivars.