Weed control in soybeans (Glycine max) with reduced rates of postemergence herbicides

• Published in: Weed science Vol. 37
• Main Authors: Defelice M.S, Brown W.B, Aldrich R.J, Sims B.D, Judy D.T, Guethle D.R
• Format: Journal Article
• Language: English
• Published: 01.05.1989
• Subjects: abutilon theophrasti; application rates; compositae; crop yield; digitaria; dose d' application; dosis de aplicacion; glycine max; herbicidas; herbicide; herbicides; ipomoea; missouri; panicum; rendement des cultures; rendimiento de cultivos; setaria graminea; setaria graminee; setaria grass
• DOI: 10.1017/S0043174500072076
• ISSN: 0043-1745

Field studies were conducted at three sites in Missouri in 1986 and 1987 to evaluate the performance of below-label rates of bentazon, acifluorfen, and chloriumuron tank mixed with sethoxydim and applied to soybeans 7 and 14 days after planting to evaluate broadleaf and grass weed control and weed seed production. Sequential applications of 0.25X-labeled rates of all three broadleaf herbicides tank mixed with 0.5X sethoxydim rates controlled giant foxtail, velvetleaf, and common cocklebur equivalent to one application of standard-labeled rates of the same tank mixes. Single applications of below-labeled rates of the postemergence herbicides did not control weeds, and soybean yields were not equal to sequential 0.25X or single full-rate treatments. A preemergence treatment of clomazone plus imazaquin applied at labeled rates controlled weeds, and soybean yields were equal to a handweeded check in both years at all test locations. Weeds survived and produced seed to reinfest the plots the following year unless nearly 100% control was achieved.