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Response of Non–Dicamba-Resistant Soybean to Dicamba As Influenced by Growth Stage and Herbicide Rate

  • Spencer McCown (a1), Tom Barber (a2) and Jason K. Norsworthy (a3)

Introduction of the Roundup Ready® Xtend system (Monsanto Co., St. Louis, MO) provides an alternative weed management option for growers, but of concern is the risk of dicamba injury to sensitive crops, particularly soybean from off-target movement and tank contamination. Experiments were conducted to determine the response of soybean to low rates of dicamba over a wide range of application timings. Two glufosinate-resistant varieties (HBK 4950LL–indeterminate and HALO 5.45LL–determinate) commonly grown in Arkansas were chosen for these studies. Two rates of dicamba, 2.18 and 8.75 g ae ha–1 (1/256× and 1/64× of the POST labeled rate for dicamba-resistant soybean), were applied at two vegetative (V4, V6) and six reproductive (R1 to R6) growth stages. Compared to the nontreated control, dicamba applied during late vegetative and early reproductive growth of soybean caused leaf injury, plant height reduction, and seed yield loss for both soybean cultivars. Averaged across dicamba rates applied at R1, soybean seed yield was reduced 14% for the HBK 4950LL cultivar and 19% for the HALO 5.45LL cultivar. Averaged over rates, dicamba applied at R1 to the HALO 5.45LL and HBK 4950LL soybean resulted in 48% and 43% visible injury 4 wk after treatment, respectively. Grain yield was similar to that of the nontreated control when dicamba was applied at the later reproductive stages averaged across rates.

Corresponding author
*Author for correspondence: Tom Barber, University of Arkansas Division of Agriculture, 2001 Hwy 70 E, Lonoke, AR 72086. (Email:
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Al-Khatib, K, Peterson, D (1999) Soybean (Glycine max) response to simulated drift from selected sulfonylurea herbicides, dicamba, glyphosate, and glufosinate. Weed Technol 13:264270
Andersen, SM, Clay, SA, Wrage, LJ, Matthees, D (2004) Soybean foliage residues of dicamba and 2,4-D and correlations to application rates and yield. Agron J 96:750760
Auch, DE, Arnold, WE (1978) Dicamba use and injury on soybeans (Glycine max) in South Dakota. Weed Sci 26:471475
Barber, LT, Norsworthy, JK, Bond, JA, Steckel, LE, Reynolds, D (2015) Dicamba effects on soybean plants and their progeny. Proc South Weed Sci Soc 68:182
Behrens, R, Lueschen, WE (1979) Dicamba volatility. Weed Sci 27:486493
Blouin, DC, Webster, EP, Bond, JA (2011) On the analysis of combined experiments. Weed Technol 25:165169
Carmer, SG, Nyquist, WE, Walker, WM (1989) Least significant differences for combined analysis of experiments with two- or three-factor treatment designs. Agron J 81:665672
Dill, GM, CaJacob, CA, Padgette, SR (2008) Glyphosate-resistant crops: adoption, use and future considerations. Pest Manag Sci 64:326331
Griffin, JL, Bauerle, MJ, Stephenson, DO III, Miller, DK, Boudreaux, JM (2013) Soybean response to dicamba applied at vegetative and reproductive growth stages. Weed Technol 27:696703
Holshouser, DL (2001) Virginia soybean production guide. Virginia Cooperative Extension Tidewater Agricultural Research and Extension Center Information Series Number 408. Blacksburg, VA: Virginia Tech University
Johnson, VA, Fisher, LR, Jordan, DL, Edmisten, KE, Stewart, AM, York, AC (2012) Cotton, peanut, and soybean response to sublethal rates of dicamba, glufosinate, and 2,4-D. Weed Technol 26:195206
Kelley, KB, Wax, LM, Hager, AG, Riechers, DE (2005) Soybean response to plant growth regulator herbicides is affected by other postemergence herbicides. Weed Sci 53:101112
Norsworthy, JK, Barber, L, Scott, R, Bond, JA, Steckel, LE, Reynolds, D (2015) Understanding risks associated with increased use of auxin herbicides in Midsouth crops: what are the concerns? Proc South Weed Sci Soc 68:264
Ritchie, SW, Hanway, JJ, Thompson, HE, Benson, GO (1994) How a soybean develops? Ames, IA: Iowa State University of Science and Technology Cooperative Extension Service Special Rep. 53:1–20
Scholtes, AB (2014) Determining the effect of auxin herbicide concentration and application timing on soybean (Glycine max) growth and yield. Master’s thesis. Starkville, MS: Mississippi State University. 57 p
Sciumbato, AS, Chandler, JM, Senseman, SA, Senseman, RW, Smith, KL (2004) Determining exposure to auxin-like herbicide. I. Quantifying injury to cotton and soybean. Weed Technol 18:11251134
Seifert-Higgins, S, Arnevik, CL (2012) Development of weed management recommendations for dicamba tolerant soybeans. Proc South Weed Sci Soc 65:266
Solomon, CB, Bradley, KW (2014) Influence of application timings and sublethal rates of synthetic auxin herbicides on soybean. Weed Technol 28:454464
Wax, LM, Knuth, LA, Slife, FW (1969) Response of soybeans to 2,4-D, dicamba and picloram. Weed Sci 17:388393
Weidenhamer, JD, Triplett, GB Jr, Sobotka, FE (1989) Dicamba injury to soybean. Agron J 81:637643
Westgate, ME (1999) Managing soybeans for photosynthetic efficiency. Crop, Soil, and Water Management. Pages 223–228 in Proceedings of the VI World Soybean Research Conference, Chicago, IL. Champaign, IL
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Weed Technology
  • ISSN: 0890-037X
  • EISSN: 1550-2740
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