Assessing bio-efficacy potential of herbicide combinations for broad spectrum weed control in late-sown wheat

Abstract

A field experiment was conducted during 2015-16 and 2016-17 at Rajasthan College of Agriculture, Udaipur, India with the objective to assess bio-efficacy potential of the ready-mix herbicides against complex weed flora in wheat. The experiment consisting of fifteen treatments, was laid out in a randomized block design with four replications. The results indicated significant reduction in population and growth of weeds by ready-mix application of sulfosulfuron + metsulfuron (32.0 g/ha) and mesosulfuron + iodosulfuron (14.4 g/ha) followed by clodinafop + metsulfuron (64.0 g/ha), pinoxaden + metsulfuron (64.0 g/ha) over other weed control treatments. However, two hand weeding (30 and 45 DAS) registered maximum decline in density and dry biomass of all the weeds. Moreover, herbicides combination sulfosulfuron + metsulfuron and mesosulfuron + iodosulfuron attributed to greater value of weed control index (WCI) with maximum reduction of weed density and dry biomass. At 60 DAS, the array of WCI ranged from 9.19 to 95.01 and 57.48 to 97.01% for monocots and dicots, respectively and resulted into higher grain yield (34.3 and 20.5% more), net returns (49.1 and 47.7% more) and B-C ratio (2.34 and 2.32) over the unweeded control. The study concluded that the use of sulfosulfuron + metsulfuron (32.0 g/ha) and mesosulfuron + iodosulfuron (14.4 g/ha) as postemergence at 5 WAS provided efficacious control of all sorts of weeds in wheat with higher yield and net returns.