Efficacy evaluation of sulfosulfuron, metsulfuron-methyl plus sulfosulfuron, mesosulfuron-methyl plus ıodosulfuron-methyl and ıodosulfuron plus mesosulfuron herbicides in winter wheat (triticum aestivum L.)

Abstract

In order to investigate the effect of sulfosulfuron, metsulfuron-methyl plus sulfosulfuron, mesosulfuron-methyl plus iodosulfuronmethyl and iodosulfuron plus mesosulfuron on weed control and wheat biological and grain yield, a two-year field experiment was conducted in Shiraz, Iran, during 2011-2012 and 2012-2013 growing seasons. The experimental design was randomized complete blocks with four replications. Treatments were sulfosulfuron at 18, 20.25 and 22.5 g a.i. ha -1 , metsulfuron-methyl plus sulfosulfuron at 28, 32 and 36 g a.i. ha -1 , mesosulfuron-methyl plus iodosulfuron-methyl at 14.4, 18 and 21.6 g a.i. ha -1 , iodosulfuron plus mesosulfuron at 18, 24 and 30 g a.i. ha -1 and two weedy and weed free checks. Compared with the weedy check, application of herbicides in both growing seasons reduced weed biomass and increased wheat biological and grain yield. Among herbicide treatments, metsulfuron-methyl plus sulfosulfuron at 36 g a.i. ha -1 reduced weed dry matter by 98. 6% and 97.55% in 2011-2012 and 2012-2013, respectively, and the lowest weed dry matter was observed with this treatment. In both years, maximum wheat biological yield was obtained in weed free check that was not significantly different from metsulfuron-methyl plus sulfosulfuron at 36 g a.i. ha -1 . The highest wheat grain yield was obtained with metsulfuron-methyl plus sulfosulfuron at 36 g a.i. ha -1