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ARS Home » Southeast Area » Auburn, Alabama » Soil Dynamics Research » Research » Publications at this Location » Publication #348775
Title: Evaluation of cotton responses to fomesafen-based treatments applied preemergence

Author
item LI, XIAO - Auburn University
item GREY, TIMOTHY - University Of Georgia
item VENCILL, WILLIAM - University Of Georgia
item FREEMAN, MARK - University Of Georgia
item PRICE, KATILYN - Auburn University
item CUTTS III, GEORGE - Auburn University
item Price, Andrew

Submitted to: Weed Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/22/2018
Publication Date: 5/7/2018
Citation: Li, X., Grey, T., Vencill, W., Freeman, M., Price, K., Cutts III, G., Price, A.J. 2018. Evaluation of cotton responses to fomesafen-based treatments applied preemergence. Weed Technology. 32:431-438. https://doi.org/10.1017/wet.2018.31.
DOI: https://doi.org/10.1017/wet.2018.31

Interpretive Summary: Fomesafen provides effective control of glyphosate resistant Palmer amaranth in cotton. However, cotton seedling injury is possible when fomesafen applied pre-emergence (PRE). Therefore, greenhouse and field experiments were conducted at Athens GA and at six locations in Alabama and Georgia in 2013 and 2016 to evaluate cotton growth and yield response to fomesafen treatments applied PRE (0, 70, 140, 280, 560, 1120, 2240 g ai ha-1, and in combination with pendimethalin, diuron, acetochlor and fluridone at 1x label rates). Data indicate cotton yield should not be negatively affected by fomesafen applied PRE within the 280-420 g ai ha-1 label rate or in combination with pendimethalin, diuron, acetochlor and fluridone at 1x label rates, although some visual injury, stand or height reduction may occur in sandy soils early in the growing season.

Technical Abstract: Fomesafen provides effective control of glyphosate resistant Palmer amaranth in cotton. However, cotton seedling injury is possible when fomesafen applied pre-emergence (PRE). Therefore, greenhouse and field experiments were conducted at Athens GA and six locations in Alabama and Georgia, respectively, in 2013 and 2016 to evaluate cotton growth and yield response to fomesafen treatments applied PRE (0, 70, 140, 280, 560, 1120, 2240 g ai ha-1, and in combination with pendimethalin, diuron, acetochlor and fluridone at 1x label rates). Greenhouse bioassay indicated fomesafen reduced cotton height and dry weight with increasing rate, as compared to non-treated check (NTC), in Cecil sandy loam and Tifton loamy sand but not in Greenville sandy clay loam, possibly due to higher organic matter and clay content in this soil. Among all treatments evaluated, fomesafen at 2240 g ai ha-1 rate reduced cotton stand up to 83% compared to NTC at all locations except for Macon and Baldwin county AL, and 1120 g ai ha-1 rate reduced cotton stand only at Pulaski county GA by 52%. Cotton height was negatively affected by fomesafen at 1120 and 2240 g ai ha-1 at all the locations in this 2-year study except for Clarke county GA and Baldwin county AL. Cotton injury from 2016 study indicated that visual injury corresponded to the increasing fomesafen rates, and locations made a significant impact on cotton injury (Pulaski > Macon > Baldwin County). High rates of fomesafen produced more injury and greater negative impact on cotton growth in sandy soils than in soils with higher clay content. Seed cotton yield was not affected by herbicide treatments at any location, except for 1120 g ai ha-1 at Pulaski County (49% yield loss compared to NTC), 2240 g ai ha-1 at Pulaski County (72% yield loss) and Tift County (29% yield loss). These data indicated cotton yield should not be negatively affected by fomesafen applied PRE within the 280-420 g ai ha-1 label rate or in combination with pendimethalin, diuron, acetochlor and fluridone at 1x label rates, although some visual injury, stand or height reduction may occur in sandy soils early in the growing season.