Yellow Nutsedge (Cyperus esculentus) Control in Cool Season Turfgrass

Abstract

Yellow nutsedge (Cyperus esculentusL.) control with herbicides was evaluated with and without competition from turfgrasses. Postemergence applications of cyperquat (1-methyl-4-phenylpryidinium) provided safe selective control of yellow nutsedge in Kentucky bluegrass (Poa pratensisL. ‘Merion’), perennial ryegrass (Lolium perenneL. ‘Manhatten’), and red fescue (Festuca rubraL. ‘Pennlawn’). Pre- and post-emergence applications of perfluidone {1,1,1-trifluoro-N-[2-methyl-4-(phenylsulfonyl)phenyl] methanesulfonamide} controlled yellow nutsedge when rainfall or irrigation was adequate for good turfgrass growth. Under dry conditions, perfluidone slightly injured Kentucky bluegrass and gave poor control of yellow nutsedge. Bentazon [3-isopropyl-1H-2,1,3-benzothiadiazin-(4)3H-one2,2-dioxide] was less effective than cyperquat or perfluidone for yellow nutsedge control and required split applications. Bentazon did not injure Kentucky bluegrass. Napropamide [2-(α-naphthoxy)-N,N-diethylpropionamide] and Vel 3973 [N-(2,4-dimethyl-5-{[(trifluoromethyl)sulfonyl]amino}phenyl)acetamide] did not provide adequate yellow nutsedge control. Vel 5052 {2-chloro-N-(2,6-dimethyl-phenyl-N-[(1,3-dioxolan-2-yl)methyl] acetamide}showed promise for yellow nutsedge control.