Weed Control in Soybean (Glycine max) with Lactofen Plus Chlorimuron

Abstract

Field experiments were conducted over a 3-yr period at three locations to evaluate lactofen at rates of 110 to 220 g ai ha−1applied POST in combination with chlorimuron at 9 g ae ha−1for weed control in soybean. At St. Joseph in 1989 and Baton Rouge in 1990, lactofen at 110, 150, and 170 g ha−1in combination with chlorimuron controlled prickly sida (3 to 5 cm) and entireleaf and pitted morningglory (5 to 13 cm) comparable with the full rate of lactofen at 220 g ha−1plus chlorimuron and the standard treatment of acifluorfen at 280 g ae ha−1plus bentazon at 560 g ae ha−1. Entireleaf morningglory and sicklepod control at Alexandria with lactofen at 110 to 170 g ha−1plus chlorimuron was comparable with that from the full rate of lactofen plus chlorimuron and better than with acifluorfen plus bentazon. Weed control was reduced when soil moisture was deficient at treatment time or when prickly sida height was more than 5 cm and entireleaf morningglory, pitted morningglory, and sicklepod more than 15 cm. In related studies at St. Joseph, a reduced rate of lactofen (170 g ha−1) in combination with chlorimuron controlled prickly sida 98%, pitted morningglory 93%, and entireleaf morningglory 90% in 1988, which was comparable with the control from the full rate of lactofen plus chlorimuron and with acifluorfen plus bentazon.

Evaluation of Reduced Rates of Glyphosate and Chlorimuron in Glyphosate-Resistant Soybean (Glycine max)1

“…Limited research has been conducted on weed control associated with reduced rates of glyphosate when applied alone and in combination with other herbicides. Chlorimuron controls many broadleaf weeds, including Ipomoea morningglory species (King and Oliver 1992;Vidrine et al 1993) and hemp sesbania (Lanie et al 1994) but does not control grass species (Jordan et al 1997). A mixture of chlorimuron with glyphosate could enhance overall weed control, provided the mixture is not antagonistic (Payne and Oliver 2000;Starke and Oliver 1998).…”

Palmer Amaranth Control with Combinations of 2,4-DB and Diphenylether Herbicides

“…The diphenylether herbicides acifluorfen and lactofen and the synthetic auxin 2,4‐DB are the only postemergence herbicides registered for use in peanut that will control or suppress escaped Palmer amaranth when ALS‐resistant biotypes are present (11). Diphenylether herbicides mixed with herbicides having a different mode of action are often more effective than either herbicide applied alone (20).…”

Light Interception and Yield Response of Ultra-Short–Season Soybean to Diphenylether Herbicides in the Midsouthern United States1

“…For soybean producers choosing not to use glyphosate, diphenylether herbicides are an effective postemergence method of controlling many of the broadleaf weeds present in the midsouthern United States soybean produc-tion area (Harris et al 1991;Vidrine et al 1993). Soybean injury is often associated with the application of diphenylether herbicides, but soybean plants typically recover without yield reduction (Harris et al 1991;Kapusta et al 1986;Krausz and Young 2001;Vidrine et al 1993;Wichert and Talbert 1993). However, all these studies evaluated the effect of diphenylether herbicides when applied to MG III and later soybean at approximately GS V4.…”