Over-reliance on ALS-inhibitor herbicides to control sedges in rice has led some common weeds of rice to develop ALS-resistance. Populations of rice flatsedge in Arkansas have confirmed resistance to ALS (Group 2) herbicides including Beyond (imazamox), Regiment (bispyribacsodium), and Grasp (penoxsulam). Management of this weed requires an integrated approach and diversified herbicide options.
Figure: ALS-resistant sedge control options for rice. University of Arkansas Cooperative Extension publication.
Herbicide resistant populations:
- Group 2 (ALS)
Locations of resistant populations: