Cotton (gossypium hirsutum) cultivar response to glufosinate plus s-metolachlor applied post using two nozzle types

Authors: GREENE, WYKLE - Auburn University; TREDAWAY, JOYCE - Auburn University; Price, Andrew; MONKS, DALE - Auburn University

Submitted to: Weed Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/5/2021
Publication Date: 3/15/2022
Citation: Greene, W., Tredaway, J., Price, A.J., Monks, D. 2022. Cotton (gossypium hirsutum) cultivar response to glufosinate plus s-metolachlor applied post using two nozzle types. Weed Technology. 35:1023-1028. https://doi.org/10.1017/wet.2021.102.
DOI: https://doi.org/10.1017/wet.2021.102

Interpretive Summary: Field studies were conducted in Alabama in 2016 and 2017 to determine the effect of postemergence applications of glufosinate alone and glufosinate applied with S-metolachlor, using two different nozzle types, on LibertyLink®, Xtend®, and WideStrike® cotton growth and yield. Two applications of glufosinate at 0.6 kg ha-1, and glufosinate with S-metolachlor at 1.39 kg ha-1 were applied to each cotton cultivar at the four-leaf and eight-leaf growth stages using a flatfan and Turbo TeeJet Induction® nozzle. Visual estimates of cotton injury were evaluated after each application, as well as yield. No differences in yield, within each cotton cultivar were observed for either year. Visual injury was higher for WideStrike cotton than LibertyLink or Xtend cultivars. On average, glufosinate applied with S-metolachlor resulted in higher injury than glufosinate applied alone. In some instances, applications made with TTI nozzles resulted in greater injury than flatfan nozzles. However, cotton injury was transient and did not affect cotton yields.

Technical Abstract: Field studies were conducted in Alabama in 2016 and 2017 to determine the effect of postemergence applications of glufosinate alone and glufosinate applied with S-metolachlor, using two different nozzle types, on LibertyLink®, Xtend®, and WideStrike® cotton growth and yield. Two applications of glufosinate at 0.6 kg ha-1, and glufosinate with S-metolachlor at 1.39 kg ha-1 were applied to each cotton cultivar at the four-leaf and eight-leaf growth stages using a flatfan and Turbo TeeJet Induction® nozzle. Visual estimates of cotton injury were evaluated after each application, as well as yield. No differences in yield, within each cotton cultivar were observed for either year. Visual injury was higher for WideStrike cotton than LibertyLink or Xtend cultivars. On average, glufosinate applied with S-metolachlor resulted in higher injury than glufosinate applied alone. In some instances, applications made with TTI nozzles resulted in greater injury than flatfan nozzles. However, cotton injury was transient and did not affect cotton yields. These data indicate that applications of glufosinate and glufosinate applied with S-metolachlor, at 0.6 kg ha-1 and 1.39 kg ha-1, respectively, with either a flatfan or TTI nozzle, made under certain conditions can have no detrimental effect on cotton growth or yield.