CENTIPEDEGRASS RESPONSE TO PLANT-GROWTH REGULATORS

A field study was conducted in southern Louisiana to screen several plant growth regulators (PGRs) for efficacy in suppressing centipedegrass [Eremochloa ophiuroides (Munro) Hack.] vegetative growth and seedhead production. PGRs were applied in three sequential treatments in 1988 and included ethephon, glyphosate, mefluidide, paclobutrazol, sethoxydim, and sulfometuron methyl. Ethephon (5.0 kg.ha-1) suppressed mean centipedegrass vegetative growth by 15% with no turf injury. Mefluidide (0.6 kg.ha-1) and ethephon reduced mean seedhead number by 55% and 61%, respectively. Glyphosate (0.6 kg.ha-1) suppressed vegetative and reproductive growth, but caused unacceptable phytotoxicity and reduced centipedegrass cover and quality during Spring 1989. Use of ethephon or mefluidide to reduce trimming requirements or mower operation in hazardous areas may be an effective means of inhibiting centipedegrass growth. Chemical names used: N-(phosphonomethyl)glycine (glyphosate); N-[2,4-dimethyl-5-[[(trifluromethyl)sulfonyl]amino]phenyl]acetamide (mefluidide); 2-[1-(ethoxyimino)butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one (sethoxydim); 2-[[[[4,6-dimethyl-2-pyrimidinyl)amino]carbonyl]amino]sulfonyl]benzoic acid (sulfometuron methyl); (2-chloroethyl)phosphonic acid (ethephon); (+/-)-R*R*)beta-[4-chlorophenyl)methyl]-alpha-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol (paclobutrazol).