Control of Kochia in Sugarbeets with 3′-Hydroxypropionanilide Isopropylcarbamate

Abstract

When the mixture of 3.4 kg/ha ofS-ethylN-ethylthiocyclohexanecarbamate (cycloate) plus 1.1 kg/ha of 3′-hydroxypropionanilide isopropylcarbamate (R 11913) was applied to three soils before planting sugarbeets (Beta vulgarisL.), the average stand of kochia (Kochia scoparia(L.) Schrad.) was reduced by 89% as compared to 9% with the standard rate of 4.5 kg/ha of cycloate. The competition of foxtail millet (Setaria italica(L.) Beauv.), redroot pigweed (Amaranthus retroflexusL.), and kochia was nearly eliminated throughout the growing season by a combination of 3.4 kg/ha of cycloate plus 1.1 kg/ha of R 11913 applied preplanting and 0.84 kg/ha of methylm-hydroxycarbanilatem-methylcarbanilate (phenmedipham) applied postemergence. This combination of treatments minimized competition from weeds all season, and the yield of sucrose was within 8% of that of the handweeded plots. Residues of the mixture of cycloate plus R 11913 were not detected biologically in two soils 8 months following application.