Evaluation of Bromoxynil, Pyraflufen-ethyl/2,4-D, and Tiafenacil for the Control of Glyphosate-resistant Canada fleabane (Conyza canadensis) in Soybean (Glycine max) and Metribuzin for the Control of Waterhemp (Amaranthus tuberculatus) with Two Mechanisms of Resistance to Photosystem II-inhibiting herbicides

Date

2021

Authors

Westerveld, David

Journal Title

Journal ISSN

Volume Title

Publisher

University of Guelph

Abstract

Fifteen field experiments were conducted in 2019 and 2020 to evaluate bromoxynil, pyraflufen-ethyl/2,4-D, and tiafenacil, alone and tankmixed with metribuzin, for the control of glyphosate-resistant (GR) Canada fleabane applied preplant in soybean. The biologically-effective-dose (BED) of bromoxynil +/- metribuzin, pyraflufen-ethyl/2,4-D +/- metribuzin, and tiafenacil +/- metribuzin was determined. Bromoxynil, pyraflufen-ethyl/2,4-D, and tiafenacil, tankmixed with metribuzin, provided similar control to the current industry standards at 8 weeks after application (WAA). Ten field and eight greenhouse experiments were conducted to evaluate metribuzin, applied preemergence (PRE) and postemergence (POST), for the control of photosystem II (PS II)-inhibitor resistant waterhemp conferred by target-site resistance (TSR) and non-target-site resistance (NTSR) mechanisms. In both the field and greenhouse studies NTSR PS II-inhibitor resistant waterhemp was controlled with metribuzin applied PRE and POST, in contrast TSR PS II-inhibitor resistant waterhemp was not controlled with metribuzin.

Description

Keywords

Waterhemp, Canada fleabane, Metribuzin, Bromoxynil, Tiafenacil, Pyraflufen-ethyl/2,4-D, Glyphosate

Citation

Westerveld, D., Soltani, N., Hooker, D., Robinson, D., & Sikkema, P. (2021). Biologically-Effective-Dose of Bromoxynil, Applied Alone and Mixed with Metribuzin, for the Control of Glyphosate-Resistant Horseweed in Soybean. Weed Technology, 1-22. doi:10.1017/wet.2021.12