Pyroxsulam: Sulfonamide Herbicide for Weed Control in Wheat in Brazil

ABSTRACT: Few herbicides are currently registered in Brazil for weed control in wheat. The objective of this research was to determine the wheat crop selectivity and the response of Lolium multiflorum to pyroxsulam. Field experiments were conducted at two locations in Paraná, Brazil. At the proposed commercial rates of 15 and 18 g a.i. ha-1 pyroxsulam did not cause visual injury above 10% in wheat. Pyroxsulam caused >10% injury in wheat at one location (Cascavel) when applied at 21, 30, 36 and 42 g a.i. ha-1; however, the crop fully recovered from the injury by 28 days after application and did not have an adverse effect on wheat grain yield, regardless of the rate applied. Pyroxsulam applied at 15 or 18 g a.i. ha-1 provided excellent control (>85%) of Lolium multiflorum in both trials.