Weed Control Efficacy and Ornamental Plant Tolerance to Dimethenamid–p + Pendimethalin Granular Herbicide

Abstract Weed control efficacy and ornamental plants tolerance to dimethenamid–p (0.75%) + pendimethalin (1%) granular herbicide was evaluated in flat tray-grown weeds container-grown plants. Dimethenamid – p at 2.94 kg ai.ha–1 (2.62 lb ai.A–1) controlled the tested broadleaf grassy >80% for up 8 wk following application. The higher rates of ≥5.88 (≥5.25 provided 94% 99% weed species but caused commercially unacceptable injury pygmyweed [Crassula radicans (Haw.) D. Dietr. ‘Red carpet']. Chocolate flower (Berlandiara lyrata Benth.) tolerated 5.88 (5.25 11.77 ai .ha–1 (10.5 rate injurious one two study years. Leucothoe [Leucothe fontanesiana (Steudel) Sleumer ‘Rainbow'] showed excellent .A–1). Herbicides used this study: 0.75% Dimethenamid–p 1% (Freehand 1.75 G), (S) 2-chloro-N-(2,4-dimethylthiophen-3-yl)-N-[(2S)-1-methoxypropan-2-yl]acetamide] N-(1-ethylpropyl)-3,4-dimethyl-2,6- dinitrobenzenamine]. Ornamental plant chocolate Benth.), leucothoe ‘Rainbow'], Carpet']. barnyardgrass [Echinochloa crus-galli (L.) Beauv.], fringed willowherb (Epilobium ciliatum Raf. ssp. ciliatum), giant foxtail (Setaria faberi Hermm.), goosegrass [Elusine indica Gaertn.], hairy bittercress (Cardamine hirsuta L.), large crabgrass [Digitaria sangunalis Scop.], redroot pigweed (Amaranthus retroflexus yellow woodsorrel (Oxalis stricta L.).