Scouringrush (Equisetum spp.) control in dryland winter wheat

Abstract

The adoption of chemical fallow rotations in Pacific Northwest dryland winter wheat production has caused a weed species composition shift in which scouringrush has established in production fields. Thus, there has been interest in identifying herbicides that effectively control scouringrush in winter wheat–chemical fallow cropping systems. Field experiments were established in growers’ fields near Reardan, WA, in 2014, and The Dalles, OR, in 2015. Ten herbicide treatments were applied to mowed and nonmowed plots during chemical fallow rotations. Scouringrush stem densities were quantified the following spring and after wheat harvest at both locations. Chlorsulfuron plus MCPA-ester resulted in nearly 100% control of scouringrush through wheat harvest. Before herbicide application, mowing had no effect on herbicide efficacy. We conclude chlorsulfuron plus MCPA-ester is a commercially acceptable treatment for smooth and intermediate scouringrush control in winter wheat–chemical fallow cropping systems; however, the lack of a positive yield response when scouringrushes were controlled should factor into management decisions.

Smooth scouringrush (Equisetum laevigatum) control with glyphosate in eastern Washington

“…In glasshouse experiments with field horsetail, Coupland and Peabody (1981) reported that 14 C-glyphosate was translocated to areas of meristematic activity in the shoot and rhizome apices and nodes; however, the amounts of radioactivity recovered from the roots and rhizomes were small relative to the amount applied. Kerbs et al (2019) did not achieve commercially acceptable control of smooth scouringrush with glyphosate, glyphosate þ saflufenacil, or glyphosate þ glufosinate. However, their maximum glyphosate rate was 1.26 kg ha -1 .…”

“…Only chlorsulfuron is labeled for use in wheat production systems. Kerbs et al (2019) found chlorsulfuron þ MCPA-ester to be a commercially acceptable treatment for smooth and intermediate (Equisetum × ferrissii Clute) scouringrush control in winter wheat-fallow cropping systems in the PNW.…”

Smooth scouringrush (Equisetum laevigatum) control with glyphosate is affected by surfactant choice and application time

“…Two direct control measures for smooth scouringrush management are extensive tillage and chlorsulfuron (WSSA Group 2) (Bernards et al 2010; Kerbs et al 2019). Tillage, especially if extensive, is not a viable option in no-till cropping systems, furthermore, the relatively long half-life for chlorsulfuron in soil limits crop rotation options (Brewster and Appleby 1983; Thirunarayanan et al 1985).…”

“…In previous studies, glyphosate has been reported to provide limited control of Equisetum species (Bernards et al 2010; Coupland and Peabody 1981; Kerbs et al 2019) at rates up to 2.1 kg ae ha –1 . However, Lyon and Thorne (2022) found that high rates of glyphosate (3.78 kg ae ha –1 ) applied alone or with an organosilicone surfactant provided effective control of smooth scouringrush 1 yr after application compared to a nontreated check.…”