Cereal rye response to eight commonly used wheat herbicides

The tolerance of cereal rye to eight herbicides registered for use in wheat, at two rates, was evaluated for potential labeling in cereal rye to expand limited chemical weed control options. Across five site-years, halauxifen-methyl + florasulam, pyroxsulam, and thifensulfuron-methyl + tribenuron-methyl applied at a 2X rate to cereal rye at Zadoks (Z) 13 caused less than 15% injury and had no impact on cereal rye density. These herbicides at the 2X rate reduced cereal rye heights 11% at 10 days after treatment (DAT), with rye recovering by 31 DAT; cereal rye heights were not reduced with these herbicides at their 1X rate. In contrast, significant injury was observed with the 1X rate of mesosulfuron-methyl (45%), pinoxaden (27%), and pinoxaden + fenoxaprop-P-ethyl (30%) applied postemergence; early-season height was reduced 19% to 26%. Residual herbicide pyroxasulfone applied as a delayed preemergence at Z 10 and flumioxazin + pyroxasulfone applied at Z 11 caused 27% to 28% and 16% to 47% injury, respectively, when the 1X rate was activated by rainfall within 2 d of application. These residual herbicides reduced cereal rye height and density up to 35% and 40%, respectively. Cereal rye grain yield was not influenced by herbicide or rate applied.