Postemergence herbicide combinations for effective Littleseed Canarygrass (Phalaris minor) control in winter wheat (Triticum aestivum L.)

Littleseed Canarygrass (Phalaris minor) is a problematic grass weed of several crops across many countries, especially in wheat fields. Two field experiments were performed over a 2-year period of 2016 and 2017 to determine the control of Littleseed Canarygrass with currently available active ingredients for winter wheat in Iran. Winter wheat was not negatively affected by herbicides examined. Pyroxasulfone, pyroxsulam, flucarbazone, thiencarbazone, clodinafop, pinoxaden + pyroxsulam, and clodinafop + sulfosulfuron controlled Littleseed Canarygrass 92-99% at 7 WAT and reduced density and dry weight with the value of 94-99% and 95-98%, respectively. Active ingredient combinations pendimethalin + thiencarbazone and flucarbazone controlled Littleseed Canarygrass 69-78% at 7 weeks after treatment (WAT) and reduced density 76-91% and biomass 80-89%, respectively. Least weed control 6% was attained for sulfosulfuron at 7 WAT and diminished density 39% and dry weight 20%. Winter wheat yield significantly increased by 26% compared to the nontreated control when Littleseed Canarygrass interference was reduced with application of clodinafop. Littleseed Canarygrass had no negative impact on wheat yield for all active ingredients. Among all active ingredients, treatments that included pyroxsulam, pyrasulfotole, flucarbazone, or thiencarbazone had the highest Littleseed Canarygrass suppression.