NEW HERBICIDES FOR VEGETABLE PRODUCTION ON PEAT SOIL

Thomas A. Bewick, Bruce A. Michaelis, Larry K. Binning, Robert L. Hughes
Herbicides with potential for use in carrot (Daucus carota L.), broccoli (Brassica oleraceae var. italica L.), celery (Apium graveolens L.), and onion (Allium cepa L.) were tested over a period of 4 years. Field plots were established in commercial plantings and arranged in a randomized complete block with either three or four replications. Visual ratings of weed control and crop injury were made. Several acetamide herbicides applied before weed emergence performed well with regard to weed control. Diethatyl

[N-(chloroacetyl)-N-(2,6-diethylphenyl)glycine] was safe for all crops tested and weed control was excellent to fair at rates from 4.5 to 9.0 kg/ha. Metolachlor[2-chloro-N-(2-ethyl-6-methylphenyl)-N- (2-methoxy-1-methylethyl)acetamide] and alachlor[2-chloro-N-(2,6- diethylpheny)-N-(methoxymethyl)acetamide] provided excellent weed control, but broccoli was injured at 4.5 and 6.7 kg/ha. Acetochlor [2-chloro-N-(ethoxymethyl)-N-(2-ethyl-6-methylphenyl) acetamide] was very effective in controlling weeds at 0.6 kg/ha, but crop tolerance was variable. Rates of acetochlor above 2.2 kg/ha injured all crops tested except onion, which tolerated rates as high as 4.5 kg/ha. Clomazone[2-(2-chlorophenyl)methyl)-4,4-dimethyl-3 isoxalidione] at 1.1 kg/ha gave excellent weed control in all crops tested, but only carrots were tolerant. Oxyfluorfen [2-chloro-1,3-ethoxy-4-nitrophenoxy) -4-(trifluoromethyl)benzene] is presently labeled for use in onion at a rate of 0.14 kg/ha and excellent weed control can be achieved. Care must be used in timing oxyfluorfen applications since it is applied after the crop has emerged and injury can result. Both sethoxydim [2-[1- (ethoxyimino) butyl]-5-[2-(ethylthio)propyl]-3-hydroxy -2-cyclohexen-1-one] and fluazifop-p [(+)-2-[4[ [5-(trifluoromethyl) -2-pyridinyl]oxy] phenoxy]propanoic acid] at 0.2 kg/ha + crop oil concentrate at 1.25% v/v for sethoxydim and 1% v/v for fluazifop provided excellent grass control with no injury of the crops tested.

Bewick, Thomas A., Michaelis, Bruce A., Binning, Larry K. and Hughes, Robert L. (1988). NEW HERBICIDES FOR VEGETABLE PRODUCTION ON PEAT SOIL. Acta Hortic. 220, 407-416
DOI: 10.17660/ActaHortic.1988.220.57
https://doi.org/10.17660/ActaHortic.1988.220.57

Acta Horticulturae