Green foxtail ( <i>Setaria viridis</i> ) and puncturevine ( <i>Tribulus terrestris</i> ) control in imazamox‐, quizalofop‐, and nicosulfuron‐resistant grain sorghum in semiarid Central Great Plains

Abstract Recent commercialization of herbicide‐resistant (HR) grain sorghum [ Sorghum bicolor (L.) Moench] hybrids, including iGrowth, DoubleTeam, and Inzen enables the use of imazamox, quizalofop, and nicosulfuron, respectively, for annual grass weed control. However, effective season‐long strategies for broad‐spectrum weed control remain lacking. Field studies were conducted in 2021 at Kansas State University Agricultural Research Center near Hays, KS, to evaluate preemergence (PRE) and postemergence (POST) herbicide programs for weed control in these HR sorghum systems. In imazamox‐resistant sorghum, imazamox (79 g ha − 1 ) applied PRE alone or with S ‐metolachlor, PRE S ‐metolachlor followed by ( fb ) POST imazamox, or POST imazamox alone achieved 84%–96% control of green foxtail ( Setaria viridis ) and puncturevine ( Tribulus terrestris ) and reduced total weed biomass by 92%–99%. In quizalofop‐resistant sorghum, PRE atrazine alone or with S ‐metolachlor fb POST quizalofop, alone or tank‐mixed with dicamba, provided 90%–97% green foxtail control. PRE atrazine fb POST quizalofop alone or mixed with 2,4‐D or dicamba controlled puncturevine by 86%–97%. In nicosulfuron‐resistant sorghum, PRE atrazine alone or with S ‐metolachlor fb POST nicosulfuron controlled green foxtail by 88%–93%. PRE atrazine fb POST nicosulfuron plus 2,4‐D or dicamba achieved 84%–95% puncturevine control. Overall, effective PRE and POST programs provided consistent, season‐long control of green foxtail and puncturevine across all three HR sorghum systems.