Skip to main content Accessibility help

Controlling Glyphosate-Resistant Palmer Amaranth (Amaranthus palmeri) in Cotton with Resistance to Glyphosate, 2,4-D, and Glufosinate

  • Rand M. Merchant (a1), A. Stanley Culpepper (a1), Peter M. Eure (a1), John S. Richburg (a2) and L. Bo Braxton (a3)...


Field experiments were conducted in Macon County, Georgia, during 2010 and 2011 to determine the impact of new herbicide-resistant cotton and respective herbicide systems on the control of glyphosate-resistant Palmer amaranth. Sequential POST applications of 2,4-D or glufosinate followed by diuron plus MSMA directed at layby (late POST-directed) controlled Palmer amaranth 62 to 79% and 46 to 49% at harvest when the initial application was made to 8- or 18–cm-tall Palmer amaranth, in separate trials, respectively. Mixtures of glufosinate plus 2,4-D applied sequentially followed by the layby controlled Palmer amaranth 95 to 97% regardless of Palmer amaranth height. Mixing glyphosate with 2,4-D improved control beyond that observed with 2,4-D alone, but control was still only 79 to 86% at harvest depending on 2,4-D rate. Sequential applications of glyphosate plus 2,4-D controlled Palmer amaranth 95 to 96% following the use of either pendimethalin or fomesafen. Seed cotton yield was at least 30% higher with 2,4-D plus glufosinate systems compared to systems with either herbicide alone. The addition of pendimethalin and/or fomesafen PRE did not improve Palmer amaranth control or yields when glufosinate plus 2,4-D were applied sequentially followed by the layby. The addition of these residual herbicides improved at harvest control (87 to 96%) when followed by sequential applications of 2,4-D or 2,4-D plus glyphosate; yields from these systems were similar to those with glufosinate plus 2,4-D. Comparison of 2,4-D and 2,4-DB treatments confirmed that 2,4-D is a more effective option for the control of Palmer amaranth. Results from these experiments suggest cotton with resistance to glufosinate, glyphosate, and 2,4-D will improve Palmer amaranth management. At-plant residual herbicides should be recommended for consistent performance of all 2,4-D systems across environments, although cotton with resistance to glyphosate, glufosinate, and 2,4-D will allow greater flexibility in selecting PRE herbicide(s), which should reduce input costs, carryover concerns, and crop injury when compared to current systems.

Experimentos de campo fueron realizados en el condado Macon, Georgia, durante 2010 y 2011 para determinar el impacto de nuevos sistemas de algodón resistentes a herbicidas y sus respectivos herbicidas en el control de Amaranthus palmeri resistente a glyphosate. Aplicaciones secuenciales POST de 2,4-D o glufosinate seguidas de diuron más MSMA dirigidas a la base del cultivo (aplicaciones POST dirigidas tarde en el ciclo de crecimiento) controlaron A. palmeri 62 a 79% y 46 a 49% al momento de la cosecha cuando la aplicación inicial se hizo a A. palmeri de 8 a 18 cm de altura, en estudios independientes, respectivamente. Mezclas de glufosinate más 2,4-D aplicados secuencialmente seguidos por la aplicación dirigida controlaron A. palmeri 95 a 97% sin importar la altura de la maleza. El mezclar glyphosate con 2,4-D mejoró el control más allá del control observado con 2,4-D solo, pero aún así el control fue solamente 79 a 86% al momento de la cosecha, dependiendo de la dosis de 2,4-D. Aplicaciones secuenciales de glyphosate más 2,4-D controlaron A. palmeri 95 a 96% cuando se usaron después de aplicaciones de pendimethalin o fomesafen. El rendimiento de semilla del algodón fue al menos 30% mayor en sistemas con 2,4-D más glufosinate en comparación con los sistemas que tuvieron solamente aplicaciones de cualquiera de estos dos herbicidas solos. La adición de pendimethalin y/o fomesafen PRE no mejoró el control de A. palmeri ni los rendimientos cuando se realizaron aplicaciones secuenciales de glufosinate más 2,4-D seguidas por aplicaciones dirigidas. La adición de estos herbicidas residuales mejoró el control al momento de la cosecha (87 a 96%) cuando fueron seguidos de aplicaciones secuenciales de 2,4-D o 2,4-D más glyphosate. Los rendimientos de estos sistemas fueron similares a los de glufosinate más 2,4-D. Comparaciones entre tratamientos de 2,4-D y 2,4-DB confirmaron que 2,4-D es una opción más efectiva para el control de A. palmeri. Los resultados de estos experimentos sugieren que el algodón con resistencia a glufosinate, glyphosate, y 2,4-D mejorará el manejo de A. palmeri. El uso de herbicidas residuales debería ser recomendado para promover un desempeño consistente de todos los sistemas con 2,4-D en diferentes ambientes, aunque el algodón con resistencia a glyphosate, glufosinate, y 2,4-D permitirá una mayor flexibilidad en la selección de herbicidas PRE, lo cual podría reducir el costo en insumos, las preocupaciones por limitaciones en la rotación de cultivos debido a larga residualidad, y el riesgo de daño del cultivo, en comparación con los sistemas actuales.


Corresponding author

Corresponding author's E-mail:


Hide All
Braxton, LB, Cui, C, Peterson, MA, Richburg, JS, Simpson, DM, Wright, TR (2010) Dow Agrosciences herbicide tolerance traits (DHT) in cotton. Page 35 in Proceedings of the Beltwide Cotton Conference, New Orleans, LA, January 4–7, 2010. Memphis, TN National Cotton Council of America
Colby, SR (1967) Calculating synergistic and antagonistic responses of herbicide combinations. Weeds. 15:2022
Collins, G, Whitaker, J, eds (2012) Georgia Cotton Production Guide. Athens, GA: University of Georgia Press
Culpepper, AS, Grey, TL, Vencill, WK, Kichler, JM, Webster, TM, Brown, SM, York, AC, Davis, JW, Hanna, WW (2006) Glyphosate-resistant Palmer amaranth (Amaranthus palmeri) confirmed in Georgia. Weed Sci 54:620626
Culpepper, AS, Webster, TM, Sosnoskie, LM, York, AC (2010) Glyphosate-resistant Palmer amaranth in the United States. Pp. 195204 in Nandula, VK, ed. Glyphosate Resistance in Crops and Weeds: History, Development and Management. 1st edn. Hoboken, NJ: Wiley
Everman, WJ, Lewis, SB, York, AC, Wilcut, JW (2009) Weed control and yield with flumioxazin, fomesafen, and S-metolachlor systems for glufosinate-resistant cotton residual weed management. Weed Technol 23:391397
Fast, BJ, Murdock, SW, Farris, RL, Willis, JB, Murray, DS (2009) Critical timing of Palmer amaranth (Amaranthus palmeri) removal in second-generation glyphosate-resistant cotton. J Cotton Sci 13:3236
Ferrell, JA, Witt, WW (2002) Comparison of glyphosate and other herbicides for weed control in corn (Zea mays): efficacy and economics. Weed Technol 16:701706
Ford, AJ, Dotray, PA, Keeling, JW, Wilkerson, JB, Wilcut, JW, Gilbert, LV. 2011. Site-specific weed management in cotton using WedHADSS™. Weed Technol 25:107112.
Frans, R, Talbert, R, Marx, D, Crowley, H (1986) Experimental design techniques for measuring and analyzing plant responses to weed control practices. in Camper, ND, ed. Research Methods in Weed Science. 3rd edn. Champaign, IL: Southern Weed Science Society. Pp 2946
Gaines, TA, Shaner, DL, Ward, SM, Leach, JE, Preston, C, Westra, P (2011) Mechanism of resistance of evolved glyphosate-resistant Palmer amaranth (Amaranthus palmeri). J Agric Food Chem 59:58865889
Grichar, WJ (1997) Control of Palmer amaranth (Amaranthus palmeri) in peanut (Arachis hypogaea) with postemergence herbicides. Weed Technol 11:739743
Jursik, M, Soukup, J, Holec, J, Andr, J (2011) Herbicide mode of actions and symptoms of plant injury by herbicides: plant growth regulator (synthetic auxin). Listy Cukrovarnicke A Reparsky 127:8892
Keeley, PE, Thullen, RJ (1989) Growth and competition of Black nightsahde (Solanum nigrum) and Palmer amaranth (Amaranthus palmeri) with cotton (Gossypium hirsutum). Weed Sci 27:326334
Lancaster, SH, Jordan, DL, Spears, JF, York, AC, Wilcut, JW, Monks, DW, Batts, RB, Brandenburg, RL (2005) Sicklepod (Senna obtusifolia) control and seed production after 2,4-DB applied alone and with fungicides and insecticides. Weed Technol 19:451455
Migo, TR, Mercado, BL, DeDatta, SK (1986) Response of Sphenochlei zeylanica to 2,4-D and other recommended herbicides for weed control in lowland rice. Philipp J Weed Sci 13:2838
Monks, CD, Kelton, JA, Patterson, MG, Price, AJ, Culpepper, AS, Marshall, MW, Nichols, RL, Steckel, LE (2012) Integrated resistant pigweed control in the southeast. Pages 141145 in Proceedings of the Beltwide Cotton Conference, Orlando, FL, January 3–6, 2012. Memphis, TN National Cotton Council of America
Morgan, GD, Bauman, PA, Chandler, JM (2001) Competitive impact of Palmer amaranth (Amaranthus palmeri) on cotton (Gossypium hirsutum) development and yield. Weed Technol 15:408412.
Neve, P, Norsworthy, JK, Smith, KL, Zelaya, IA (2011) Modeling glyphosate-resistance management strategies for Palmer amaranth (Amaranthus palmeri) in cotton. Weed Technol 25:335343
Norsworthy, JK, Griffith, GM, Scott, RC, Smith, KL, Oliver, LR (2008) Confirmation and control of glyphosate-resistant Palmer amaranth (Amaranthus palmeri) in Arkansas. Weed Technol 22:108113
Peterson, GE (1967) The discovery and development of 2,4–D. Agric Hist 41:243254
Price, AJ, Balkcom, KS, Culpepper, AS, Kelton, JA, Nichols, RL, Schomberg, H (2011) Glyphosate-resistant Palmer amaranth: a threat to conservation tillage. J Soil Water Conserv 66:265275
Richburg, JS, Wright, JR, Braxton, LB, Robinson, AE, inventors; Dow Agrosciences, assignee (2012) 12 July. Increased tolerance of DHT-enabled plants to auxinic herbicides resulting from MOIETY differences in auxinic molecule structures. U.S. patent 13,345,236
Rowland, MW, Murray, DS, Verhalen, LM (1999) Full season Palmer amaranth (Amaranthus palmeri) interference with cotton (Gossypium hirsutum). Weed Sci 47:305309
Sosnoskie, LM, Culpepper, AS (2012) Changes in cotton weed management practices following the development of glyphosate-resistant Palmer amaranth. Page 1520 in Proceedings of the Beltwide Cotton Conference, Orlando, FL, January 3–6, 2012. Memphis, TN National Cotton Council of America
Sosnoskie, LM, Kichler, JM, Wallace, RD, Culpepper, AS (2011) Multiple resistance in Palmer amaranth to glyphosate and pyrithiobac confirmed in Georgia. Weed Sci 59:321325
Triplett, GB, Lytle, GD (1972) Control and ecology of weeds in continuos corn grown without tillage. Weeds Sci 20:453457
[USDA] U.S. Department of Agriculture (2012) Acreage. Accessed February 12, 2013
[USDA] United States Department of Agriculture (2004) Acreage. Accessed: February 13, 2013
Whitaker, JR, York, AC, Jordan, DL, Culpepper, AS (2011a) Weed management with glyphosate- and glufosinate-based systems in PHY 485 WRF Cotton. Weed Technol 25:183191
Whitaker, JR, York, AC, Jordan, DL, Culpepper, AS, Sosnoskie, LM (2011b) Residual herbicides for Palmer amaranth control. J Cotton Sci 15:8999
Wright, TR, Shan, G, Walsh, TA, Lira, JM, Cui, C, Song, P, Zhuang, M, Arnold, NL, Lin, G, Yau, K, Russell, SM, Cicchillo, RM, Peterson, MA, Simpson, DM, Zhou, N, Ponsamuel, J, Zhang, Z (2010) Robust crop resistance to broadleaf and grass herbicides provided by aryloxyalkanoate dioxygenase transgenes. Proc Natl Acad Sci USA 107:2024020245


Controlling Glyphosate-Resistant Palmer Amaranth (Amaranthus palmeri) in Cotton with Resistance to Glyphosate, 2,4-D, and Glufosinate

  • Rand M. Merchant (a1), A. Stanley Culpepper (a1), Peter M. Eure (a1), John S. Richburg (a2) and L. Bo Braxton (a3)...


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed