Control of Purple Nutsedge (Cyperus rotundus) with Herbicides and Mowing¹

Abstract

Purple nutsedge management with herbicides (halosulfuron, imazaquin, MSMA, S-metolachlor, and sulfentrazone) and mowing was investigated in a bare ground homogenous purple nutsedge field site. Mowing at 5 cm increased control of purple nutsedge by 6% compared to not mowing. Sequential applications of halosulfuron, MSMA, and sulfentrazone provided at least 80% control of purple nutsedge shoots, whereas imazaquin controlled purple nutsedge shoots less than 65%. All herbicide treatments reduced purple nutsedge total and viable tuber densities at least 40%. S-metolachlor PRE reduced total and viable tuber densities 65 and 69%, respectively. Sequential applications of sulfentrazone or MSMA reduced total and viable tubers 80%. Early postemergence (EPOST) or EPOST followed by late-postemergence applications of halosulfuron and imazaquin reduced total and viable tuber densities 52 and 59%, respectively. Data indicate that S-metolachlor PRE and sequential applications of MSMA and sulfentrazone may be viable treatments for control of purple nutsedge shoots and tubers.Nomenclature: Halosulfuron; imazaquin; MSMA; S-metolachlor; sulfentrazone; purple nutsedge, Cyperus rotundus L. #3 CYPRO.Additional index words: Purple nutsedge control, purple nutsedge tuber viability.Abbreviations: EPOST, early postemergence; LPOST, late-postemergence; WALP, weeks after late-postemergence; WAT, weeks after treatment.