Broadleaf Weed Control with Sulfentrazone and Flumioxazin in No-Tillage Soybean (Glycine max)

Abstract

Field trials were conducted at two sites in 1996 and 1997 to evaluate weed control and crop response to herbicide programs in no-till soybean that include flumioxazin or sulfentrazone alone and each herbicide tank-mixed with either chlorimuron or imazaquin. A prepackaged mixture of metribuzin plus chlorimuron also was included for comparison. Cool, wet conditions after herbicide application in both years were conducive to soybean injury up to 21% at 3 wk after planting (WAP). Flumioxazin and sulfentrazone alone provided ≥ 89% control of velvetleaf, Pennsylvania smartweed, and common cocklebur. Sulfentrazone alone provided greater control of common waterhemp, common cocklebur, and ivyleaf and pitted morningglories than flumioxazin. Flumioxazin provided greater control of common ragweed than sulfentrazone. The addition of chlorimuron to flumioxazin or sulfentrazone provided greater control of velvetleaf than flumioxazin or sulfentrazone alone. The addition of imazaquin or chlorimuron to flumioxazin provided greater control of common cocklebur than flumioxazin alone. The addition of imazaquin or chlorimuron to sulfentrazone provided greater control of common ragweed than sulfentrazone alone. The addition of chlorimuron or imazaquin to sulfentrazone or flumioxazin provided little or no additional control of pitted morningglory, common waterhemp, or Pennsylvania smartweed. Metribuzin plus chlorimuron provided control of velvetleaf, Pennsylvania smartweed, common ragweed, and common cocklebur that was equal to or better than the control provided by sulfentrazone or flumioxazin plus chlorimuron or imazaquin.