Skip to main content Accessibility help

Assessment of Weed Management Practices and Problem Weeds in the Midsouth United States—Soybean: A Consultant's Perspective

  • Dilpreet S. Riar (a1), Jason K. Norsworthy (a1), Lawrence E. Steckel (a2), Daniel O. Stephenson (a3), Thomas W. Eubank (a4) and Robert C. Scott (a5)...


Soybean consultants from Arkansas, Louisiana, Mississippi, and Tennessee were surveyed by direct mail and by on-farm visits in fall 2011 to assess weed management practices and the prevalence of weed species in midsouth U.S. soybean. These consultants represented 15, 21, 5, and 10% of total soybean planted in Arkansas, Louisiana, Mississippi, and Tennessee, respectively, in 2011. Collectively, 93% of the total scouted area in these four states was planted with glyphosate-resistant (RR) soybean. The adoption of glufosinate-resistant (LL) soybean was greatest in Arkansas (12%), followed by Tennessee (4%), Mississippi (2%), and Louisiana (< 1%). Only 17% of the RR soybean was treated solely with glyphosate, compared with 35% of LL soybean treated solely with glufosinate. Across four states, average cost of herbicides in RR and LL soybean systems was US$78 and US$91 ha−1, respectively. Collectively across states, total scouted area under conventional tillage was 42%, stale seedbed was 37%, and no-tillage was 21%. Palmer amaranth and morningglories were the most problematic weeds in all four states. Additionally, barnyardgrass and horseweed were the third most problematic weeds of Arkansas and Tennessee, respectively, and Italian ryegrass was the third most problematic weed in Louisiana and Mississippi. Glyphosate-resistant Palmer amaranth infested fewer fields in Louisiana (16% of fields) than it did in the remaining three states (54% collectively). Average Palmer amaranth hand-weeding costs in the midsouth was US$59 ha−1. Three-fourths of the midsouth consultants stipulated the need for continued research and education focused on management of glyphosate-resistant and glyphosate-tolerant weed species.

Asesores en soya de Arkansas, Louisiana, Mississippi, y Tennessee fueron encuestados vía correo y visitas en finca en el otoño de 2011 para evaluar las prácticas de manejo de malezas y la prevalencia de especies de malezas en la producción de soya en el Sur medio de los Estados Unidos. Estos asesores representaron 15, 21, 5 y 10% del total de soya plantada en Arkansas, Louisiana, Mississippi, y Tennessee, respectivamente en 2011. Colectivamente, 93% del total del área evaluada en estos cuatro estados fue sembrada con soya resistente a glyphsoate (RR). La adopción de soya resistente a glufosinate (LL) fue mayor en Arkansas (12%), seguida por Tennessee (4%), Mississippi (2%) y Louisiana (<1%). Solamente 17% de la soya RR fue tratada únicamente con glyphosate, al compararse con 35% de soya LL que fue tratada solamente con glufosinate. En los cuatro estados, el costo promedio de herbicidas en sistemas de soya RR y LL fue US$78 y US$91 ha−1, respectivamente. Colectivamente en los estados, el total del área evaluada que estuvo bajo labranza convencional fue 42%, siembra retrasada 37%, y cero labranza 21%. Amaranthus palmeri e Ipomoea spp. fueron las malezas más problemáticas en todos los cuatro estados. Adicionalmente, Echinochloa crus-galli y Conyza canadensis fueron las terceras malezas más problemáticas en Arkansas y Tennessee, respectivamente, y Lolium perenne fue la tercera maleza más problemática en Louisiana y Mississippi. A. palmeri resistente a glyphosate infestó menos campos en Louisiana (16% de los campos) que en el resto de los tres estados (54% colectivamente). El promedio del costo de deshierba manual de A. palmeri en el Sur medio fue de US$59 ha−1. Tres cuartos de los asesores del Sur medio estipularon la necesidad de investigación y educación continuas enfocadas en el manejo de malezas resistentes y tolerantes a glyphosate


Corresponding author

Corresponding author's E-mail:


Hide All
Bagavathiannan, M. V., Norsworthy, J. K., Smith, K. L., and Burgos, N. 2011. Seedbank size and emergence pattern of barnyardgrass (Echinochloa crus-galli) in Arkansas. Weed Sci. 59:359365.
Ball, D. A. 1992. Weed seedbank response to tillage, herbicides, and crop rotation sequence. Weed Sci. 40:654659.
Baltazar, A. M. and Smith, R. J. Jr. 1994. Propanil-resistant barnyardgrass (Echinochloa crus-galli) control in rice (Oryza sativa). Weed Sci. 8:576581.
Benbrook, C. 2009. Impacts of Genetically Engineered Crops on Pesticide Use in the United States: The First Thirteen Years. Accessed: October 2, 2012.
Bonny, S. 2011. Herbicide-tolerant transgenic soybean over 15 years of cultivation: pesticide use, weed resistance, and some economic issues: the case of the USA. Sustainability. 3:13021322.
Bradley, J. F. 2000. Economic comparison of weed control systems in conservation tillage systems. Pages 14741476 in Dugger, C. P. and Richter, D. A., eds. Proceedings of the Beltwide Cotton Conference, January 4–8, 2000, San Antonio, TX. Memphis, TN National Cotton Council of America.
Cardina, J., Herms, C. P., and Doohan, D. J. 2002. Crop rotation and tillage system effects on weed seedbanks. Weed Sci. 50:448460.
Cerdeira, A. L. and Duke, S. O. 2006. The current status and environmental impacts of glyphosate-resistant crops: a review. J. Environ. Qual. 35:16331658.
Coetzer, E., Al-Khatib, K., and Loughin, T. M. 2001. Glufosinate efficacy, absorption, and translocation in amaranth as affected by relative humidity and temperature. Weed Sci. 49:813.
Culpepper, A. S., York, A. C., Batts, R. B., and Jennings, K. M. 2000. Weed management in glufosinate- and glyphosate-resistant soybean (Glycine max). Weed Technol. 14:7788.
DeVore, J. D., Norsworthy, J. K., and Brye, K. 2013. Influence of deep tillage, a rye cover crop, and various soybean production systems on Palmer amaranth emergence in soybean. Weed Technol. DOI:.
Fernandez-Cornejo, J. and Caswell, M. 2006. The first decade of genetically engineered crops in the United States. Washington, DC U.S. Department of Agriculture, Economic Research Service, Economic Information Bulletin No. 11.
Green, J. M. and Owen, M. D. K. 2011. Herbicide-resistant crops: utilities and limitations for herbicide-resistant weed management. J. Agric. Food Chem. 59:58195829.
Griffin, J. W. and Webster, E. P. 2012. Fighting Weeds in Louisiana Agriculture for 125 years. Accessed: October 18, 2012.
Hammond, E. 2010. Genetically Engineered Backslide: The Impact of Glyphosate-Resistant Palmer Pigweed on Agriculture in the United States. Penang, Malaysia Third World Network, TWN Biotechnology and BioSafety Series 12. Pp. 122
Heap, I. 2012. The International Survey of Herbicide Resistant Weeds. Accessed: September 1, 2012.
Horowitz, J., Ebel, R., and Ueda, K. 2010. “No-Till” Farming is a Growing Practice. Washington, DC United States Department of Agriculture, Economic Research Service, Economic Information Bulletin 70.
Hoss, N. E., Al-Khatib, K., Peterson, D. E., and Loughin, T. M. 2003. Efficacy of glyphosate, glufosinate, and imazethapyr on selected weed species. Weed Sci. 51:110117.
Hurley, T. M., Mitchell, P. D., and Frisvold, G. B. 2009. Weed management costs, weed best management practices, and the Roundup Ready® weed management program. Agbioforum. 12:281290.
Jha, P. and Norsworthy, J. K. 2009. Soybean canopy and tillage effects on emergence of Palmer amaranth (Amaranthus palmeri) from a natural seed bank. Weed Sci. 57:644651.
Jordan, D. L., York, A. C., Griffin, J. L., Clay, P. A., Vidrine, P. R., and Reynolds, D. B. 1997. Influence of application variables on efficacy of glyphosate. Weed Technol. 11:354362.
Koger, C. H., Poston, D. H., Hayes, R. M., and Montgomery, R. F. 2004. Glyphosate-resistant (Conyza canadensis) horseweed in Mississippi. Weed Technol. 18:820825.
Kruger, G. R., Johnson, W. G., Weller, S. C., Owen, M. D. K., Shaw, D. R., Wilcut, J. W., Jordan, D. L., Wilson, R. G., Bernards, M. L., and Young, B. G. 2009. U.S. grower views on problematic weeds and changes in weed pressure in glyphosate-resistant corn, cotton, and soybean cropping systems. Weed Technol. 23:162166.
Lovelace, M. L. 2003. Implications of Quinclorac Use in Arkansas: Impacts of Quinclorac Drift on Tomato Physiology and Development of Quinclorac Resistance in Barnyardgrass. Ph.D Dissertation. Fayetteville, AR University of Arkansas. Pp. 7071.
Mueller, T. C., Mitchell, P. D., Young, B. G., and Culpepper, A. S. 2005. Proactive versus reactive management of glyphosate-resistant or -tolerant weeds. Weed Technol. 19:924933.
Nandula, V. K., Reddy, K. N., Koger, C. H., Poston, D. H., Rimando, A. M., Duke, S. O., Bond, J. A., and Ribeiro, D. N. 2012. Multiple resistance to glyphosate and pyrithiobac in Palmer amaranth (Amaranthus palmeri) from Mississippi and response to flumiclorac. Weed Sci. 60:179188.
Neve, P., Diggle, A. J., Smith, F. P., and Powles, S. B. 2003. Simulating evolution of glyphosate resistance in Lolium rigidum I: population biology of a rare resistance trait. Weed Res. 43:404417.
Neve, P., Norsworthy, J. K., Smith, K. L., and Zelaya, I. A. 2011. Modelling evolution and management of glyphosate resistance in Amaranthus palmeri . Weed Res. 51:99112.
Nichols, R. L., Bond, J., and Culpepper, A. S., et al. 2009. Glyphosate-resistant Palmer amaranth (Amaranthus palmeri) spreads in the Southern United States. Resist. Pest Manag. Newsl. 18:810.
Norsworthy, J. K. 2003. Use of soybean production surveys to determine weed management needs of South Carolina farmers. Weed Technol. 17:195201.
Norsworthy, J. K. 2008. Effect of tillage intensity and herbicide programs on changes in weed species density and composition in the southeastern coastal plains of the United States. Crop Prot. 27:151160.
Norsworthy, J. K. and Oliver, L. R. 2002. Effect of irrigation, soybean density, and glyphosate on hemp sesbania (Sesbania exaltata) and pitted morningglory (Ipomoea lacunosa) interference in soybean. Weed Technol. 16:717.
Norsworthy, J. K., Bagavathiannan, M. V., Neve, P., Smith, K., and Zelaya, I. 2011. Integrating nonchemical practices into simulation modeling for herbicide resistance: a proactive strategy. Abstract 226 in Proceedings of the Annual Meeting of the Weed Science Society of America, February 7–11, 2011, Portland, OR. Champaign, IL WSSA.
Norsworthy, J. K., Griffith, G. M., Scott, R. C., Smith, K. L., and Oliver, L. R. 2008. Confirmation and control of glyphosate-resistant Palmer amaranth (Amaranthus palmeri) in Arkansas. Weed Technol. 22:108113.
Norsworthy, J. K., Scott, R., Smith, K., Still, J., Estorninos, L. E. Jr., and Bangarwa, S. 2009. Confirmation and management of clomazone-resistant barnyardgrass in rice. Abstract 211. in Proceedings of the Southern Weed Science Society, Orlando, FL, Volume 62.
Norsworthy, J. K., Smith, K. L., Scott, R. C., and Gbur, E. E. 2007. Consultant perspectives on weed management needs in Arkansas cotton. Weed Technol. 21:825831.
Norsworthy, J. K., Ward, S. M., Shaw, D. R., Llewellyn, R. S., Nichols, R. L., Webster, T. M., Bradley, K. W., Frisvold, G., Powles, S. B., Burgos, N. R., Witt, W. W., and Barrett, M. 2012. Reducing the risks of herbicide resistance: best management practices and recommendations. Weed Sci. Special Issue. Pp. 3162.
[NRC] National Research Council. 2010. Impact of Genetically-Engineered Crops on Farm Sustainability in the United States. Washington, DC The National Academies Press.
Osunsami, S. 2009. Killer Pigweeds Threaten Crops in the South. Accessed: October 1, 2012.
Prince, J. M., Shaw, D. R., Givens, W. A., Newman, M. E., Owen, M.D.K., Weller, S. C., Young, B. G., Wilson, R. G., and Jordan, D. L. 2012a. Benchmark Study: III. Survey on changing herbicide use patterns in glyphosate-resistant cropping systems. Weed Technol. 26:536542.
Prince, J. M., Shaw, D. R., Givens, W. A., Owen, M.D.K., Weller, S. C., Young, B. G., Wilson, R. G., and Jordan, D. L. 2012b. Benchmark study, I: introduction, weed population, and management trends from the benchmark survey 2010. Weed Technol. 26:525530.
Prostko, E. 2010. Consider Metribuzin in Soybeans. Assessed: October 16, 2012.
Reddy, K. N. and Norsworthy, J. K. 2010. Glyphosate-resistant crop production systems: impact on weed species shifts. Pages 165184 in Nandula, V. K., ed. Glyphosate Resistance in Crops and Weeds: History, Development, and Management. Singapore J. Wiley.
Riar, D. S., Norsworthy, J. K., Bond, J. A., Bararpour, M. T., Wilson, M. J., and Scott, R. C. 2012. Resistance of Echinochloa crus-galli populations to acetolactate synthase-inhibiting herbicides. Intl. J. Agron. DOI:.
Riar, D. S., Norsworthy, J. K., and Griffith, G. M. 2011a. Herbicide programs for enhanced glyphosate-resistant and glufosinate-resistant cotton (Gossypium hirsutum). Weed Technol. 25:526534.
Riar, D. S., Norsworthy, J. K., Johnson, D. B., Scott, R. C., and Bagavathiannan, M. 2011b. Glyphosate resistance in a johnsongrass (Sorghum halepense) biotype from Arkansas. Weed Sci. 59:299304.
Riar, D. S., Norsworthy, J. K., Srivastava, V., Nandula, V., Bond, J. A., and Scott, R. C. 2013. Physiological and molecular basis of acetolactate synthase-inhibiting herbicide resistance in barnyardgrass (Echinochloa crus-galli). J. Agri. Food Chem. 61:278289.
Ross, J., Eubank, T., Norsworthy, J. K., and Scott, R. C. 2011. 2011 Soybean Variety Screening for Metribuzin Sensitivity. University of Arkansas Division of Agriculture, Cooperative Extension Service. Accessed: October 2, 2012.
Scott, R. C., Boyd, J. W., Selden, G., Norsworthy, J. K., and Burgos, N. 2013. Recommended Chemicals for Weed and Brush Control. Little Rock, AR The University of Arkansas Division of Agriculture Cooperative Extension Service, Miscellaneous Publication 44. Pp 36.
Shaner, D. L. 2000. The impact of glyphosate-resistant crops on the use of other herbicides and resistance management. Pest Manag Sci. 56:320326.
Sosnoskie, L. M. and Culpepper, S. 2012. 2012: Changes in cotton weed management practices in Georgia following the development of glyphosate-resistant Palmer amaranth. Proc. 2012 Beltwide Cotton Conference. Web page: Accessed: October 2, 2012.
Steckel, L. E. 2011. Glyphosate-resistant weeds: lessons learned in Tennessee. In: Proceedings of the 2011 Crop Pest Management Shortcourse & Minnesota Crop Production Retailers Trade Show. Accessed October 2, 2012.
Steckel, L. E., Main, C. L., Ellis, A. T., and Mueller, T. C. 2008. Palmer amaranth (Amaranthus palmeri) in Tennessee has low level glyphosate resistance. Weed Technol. 22:119123.
Tharp, B. E. and Kells, J. J. 2002. Residual herbicides used in combination with glyphosate and glufosinate in corn (Zea mays). Weed Technol. 16:274281.
Thompson, C. and Peterson, D. 2012. A Palmer amaranth population resistant to HPPD herbicides. Abstract 68-1 in: Visions for a Sustainable Plant: Proceedings of the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America International Annual Meetings, October 21–24, 2012, Cincinnati, OH. Madison, WI ASA, CSSA, and SSSA.
[USDA-NASS] United States Department of Agriculture, National Agricultural Statistics Service. 2012. Acreage: Accessed: October 2, 2012.
[USDA-NRCS] United States Department of Agriculture, National Resource Conservation Service. 2000. Residue Management in No-Till. Washington, DC Natural Resource Conservation Service Tennessee Jobsheet 329A.
Vencill, W. K., Nichols, R. L., Webster, T. M., Soteres, J. K., Mallory-Smith, C., Burgos, N. R., Johnson, W. G., and McClelland, M. R. 2012. Herbicide resistance: toward an understanding of resistance development and the impact of herbicide-resistant crops. Weed Sci. 2012 Special Issue. Pp. 230.
Webster, T. M. and MacDonald, G. E. 2001. A survey of weeds in various crops in Georgia. Weed Technol. 15:771790.
Webster, T. M. and Sosnoskie, L. M. 2010. Loss of glyphosate efficacy: a changing weed spectrum in Georgia cotton. Weed Sci. 58:7379.


Related content

Powered by UNSILO

Assessment of Weed Management Practices and Problem Weeds in the Midsouth United States—Soybean: A Consultant's Perspective

  • Dilpreet S. Riar (a1), Jason K. Norsworthy (a1), Lawrence E. Steckel (a2), Daniel O. Stephenson (a3), Thomas W. Eubank (a4) and Robert C. Scott (a5)...


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.