Journal or Publishing Institution: Weed Technology
Author(s): Thomas, W.E., Burke, I.C., Robinson, B.L., Pline-Srnić, W.A., Edmisten, K.L., Wells, R. and Wilcut, J.W.
Article Type: Peer Reviewed Study
Record ID: 1979
Abstract: Field studies were conducted in 2001 in Lewiston, NC, and in 2002 at Clayton and Lewiston, NC, to investigate the response of nontransgenic cotton to simulated glyphosate drift in a weed-free environment. Nontransgenic cotton variety ‘Fibermax 989’ was planted in a conventional seedbed at all locations. Glyphosate treatments were applied early postemergence (EPOST) at the four-leaf growth stage of cotton at 0, 8.7, 17.5, 35, 70, 140, 280, 560, and 1,120 g ai/ha and represent 0, 0.78, 1.55, 3.13, 6.25, 12.5, 25, 50, and 100% of the commercial use rate, respectively. Rates as low as 140 g/ha caused lint yield reductions depending on year and location. When averaged over all locations, lint yield reductions of 4, 49, 72, and 87% compared with nontreated cotton were observed with glyphosate rates of 140, 280, 560, and 1,120 g/ha, respectively. Visual injury and shikimic acid accumulation were evident at glyphosate rates greater or equal to 70 g/ha. Collectively, visual injury and shikimic acid accumulation at 7 d after EPOST treatment might be used as a diagnostic indicator to predict potential yield reductions from simulated glyphosate drift.
Keywords: Glyphosate, cotton, Gossypium hirsutum L. ‘Fibermax 989’ Shikimic acid, Days after early postemergence treatment, degree-day, EPOST, early postemergence, EPSPS, 5-enolpyruvylshikimate-3-phosphate synthase, HPLC, high-performance liquid chromatography, PDS, postemergence-directed, postemergence, preemergence
Citation: Thomas, W.E., Burke, I.C., Robinson, B.L., Pline-Srnić, W.A., Edmisten, K.L., Wells, R. and Wilcut, J.W., 2005. Yield and physiological response of nontransgenic cotton to simulated glyphosate drift. Weed Technology, 19(1), pp.35-42.
