Bentgrass and Bermudagrass Putting Green Turf Tolerance to Postemergence Herbicides

Abstract

Abstract Field experiments were conducted to evaluate response of ‘Penncross’ creeping bentgrass ( Agrostis palustris Huds.) and ‘Tifgreen II bermudagrass [ Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt-Davy] to six postemergence herbicides. Fluazifop and sethoxydim were applied at 0.1, 0.2, and 0.3 kg ha −1 . Fenoxaprop, haloxyfop, xylafop, and poppenate were evaluated at 0.07, 0.15, and 0.30 kg −1 . Crop oil concentrate was added to each treatment at 2.4 liters·ha −1 . Herbicides were applied in June 1985 to bentgrass, and in June and Aug. 1985 to bermudagrass. Bentgrass and bermudagrass had unacceptable color and density through 28 days after treatment (DAT) with all herbicides. Both species showed tolerance 28 DAT to fenoxaprop at 0.07 and 0.15 kg ha −1 , but turf density was reduced compared to the untreated check. Bermudagrass quality at 42 and 49 DAT was not different from the untreated check with low and medium rates of fenoxaprop. All other herbicides reduced bentgrass and bermudagrass quality to unacceptable levels. Chemical names used: (±)-2-ethoxy-2,3-dihydro-3,3-dimethyl-5-benzofuranyl methanesulfonate (ethofumesate); (±)-2[4-[(6-chloro-2-benzoxazolyl)oxy]phenoxy]propanoate (fenoxaprop); (±)-2-[4-[[5-(trifluoromethyl)-2-pyridinyl]oxyl]phenoxy]propanoic acid (fluazifop); 2-[4-[[3-chloro-5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy]propanoic acid (haloxyfop); methyl-3-hydroxy-4[4-[[5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy]-pentanoate (poppenate); 2-[1-(ethoxyi-mino)butyl]-5-]2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one (sethoxydim); 2-[4-[(6-chloro-2-quinoxalinyl)oxy]phenoxyl]propanoic acid (xylafop).