Skip to main content Accessibility help

Seed Retention of Palmer amaranth (Amaranthus palmeri) and Barnyardgrass (Echinochloa crus-galli) in Soybean

  • Lauren M. Schwartz-Lazaro (a1), Jeremy K. Green (a1) and Jason K. Norsworthy (a1)


Harvest weed seed control is an alternative non-chemical approach to weed management that targets escaped weed seeds at the time of crop harvest. Relatively little is known on how these methods will work on species in the US. Two of the most prominent weeds in soybean production in the midsouthern US are Palmer amaranth and barnyardgrass. Typically, when crop harvesting occurs the weed seed has already either shattered or is taken into the combine and may be redistributed in the soil seedbank. This causes further weed seed spread and may contribute to the addition of resistant seeds in the seedbank. There is little research on how much seed is retained on different weed species at or beyond harvest time. Thus, the objective of this study was to determine the percentage of total Palmer amaranth and barnyardgrass seed production that was retained on the plant during delayed soybean harvest. Retained seed over time was similar between 2015 and 2016, but was significantly different between years for only Palmer amaranth. Seed retention did not differ between years for either weed species. Palmer amaranth and barnyardgrass retained 98 and 41% of their seed at soybean maturity and 95 and 32% of their seed one month after soybean maturity, respectively. Thus, this research indicates that if there are escaped Palmer amaranth plants and soybean is harvested in a timely manner, most seed will enter the combine and offer potential for capture or destruction of these seeds using harvest weed seed control tactics. While there would be some benefit to using HWSC for barnyardgrass, the utility of this practice on mitigating herbicide resistance would be less pronounced than that of Palmer amaranth because of the reduced seed retention or early seed shatter.


Corresponding author

*Corresponding author’s E-mail:


Hide All

Associate Editor for this paper: Lawrence E. Steckel, University of Tennessee



Hide All
Bagavathiannan, MV, Norsworthy, JK, Smith, KL, Neve, P (2011) Seed production of barnyardgrass (Echinochloa crus-galli) in response to time of emergence in cotton and rice. J Agric Sci 150:717724
Bensch, CN, Horak, MJ, Peterson, D (2003) Interference of redroot pigweed (Amaranthus retroflexus), Palmer amaranth (Palmer amaranth), and common waterhemp (A. rudis) in soybean. Weed Sci 51:3743
Bosnic, AC, Swanton, CJ (1997) Influence of barnyardgrass (Echinochloa crus-galli) time of emergence and density on corn (Zea mays). Weed Sci 45:276282
Burton, NR, Beckie, HJ, Willenborg, CJ, Shirtliffe, SJ, Schoneau, JJ, Johnson, EN (2016) Evaluating seed shatter of economically important weed species. Weed Sci 64:673682
Dalley, CD, Kells, JJ, Renner, KA (2004) Effect of glyphosate application timing and row spacing on weed growth in corn (Zea mays) and soybean (Glycine max). Weed Technol 18:177182
Goplen, JJ, Shaeffer, CC, Becker, RL, Coulter, JA, Breitenbach, FR, Behnken, LM, Johnson, GA, Gunsolus, JL (2016) Giant ragweed (Ambrosia trifida) seed production and retention in soybean and field margins. Weed Technol 30:246253
Heap, I (2016) The International Survey of Herbicide Resistant Weeds. Accessed December 7, 2016
Jha, P, Norsworthy, JK, Bridges, W, Riley, MB (2008) Influence of glyphosate timing and row width on Palmer amaranth (Amaranthus palmeri) and pusley (Richardia spp.) demographics in glyphosate-resistant soybean. Weed Sci 56:408415
Keeley, PE, Carter, CH, Thullen, RJ (1987) Influence of planting date on growth of Palmer amaranth (Amaranthus palmeri). Weed Sci 35:199204
Massinga, RA, Currie, RS, Horak, MJ, Boyer, J Jr (2001) Interference of Palmer amaranth in corn. Weed Sci 49:202208
Nordby, D, Hartzler, B, Bradley, K (2007) Biology and Management of Waterhemp. West Lafayette, IN: Purdue Extension GWC-13
Norsworthy, JK, Griffith, G, Griffin, T, Bagavathiannan, M, Gbur, EE (2014) In-field movement of glyphosate-resistant Palmer amaranth (Amaranthus palmeri) and its impact on cotton lint yield: evidence supporting a zero-threshold strategy. Weed Sci 62:237249
Norsworthy, JK, Ward, SM, Shaw, DR, Llewellyn, RS, Nichols, RL, Webster, TM, Bradley, KW, Frisvold, G, Powles, SB, Burgos, NR, Witt, WW, Barrett, M (2012) Reducing the risks of herbicide resistance: best management practices and recommendations. Weed Sci 60:3162
Schwartz, LM, Gibson, DJ, Gage, KL, Matthews, JL, Jordan, DL, Owen, MDK, Shaw, DR, Weller, SC, Wilson, RG, Young, BG (2015) Seedbank and field emergence of weeds in glyphosate-resistant cropping systems in the United States. Weed Sci 63:425439
Schwartz, LM, Norsworthy, JK, Young, BG, Bradley, KW, Kruger, GR, Davis, VM, Steckel, LE, Walsh, MJ (2016) Tall waterhemp (Amaranthus tuberculatus) and Palmer amaranth (Amaranthus palmeri) seed production and retention at soybean maturity. Weed Technol 30:284290
Sellers, BA, Smeda, RJ, Johnson, WG, Kendig, JA, Ellersieck, MR (2003) Comparative growth of six Amaranthus species in Missouri. Weed Sci 51:329333
Swanton, CJ, Weise, SF (1991) Integrated weed management: the rationale and approach. Weed Technol 5:657663
Vail, GD, Oliver, LR (1993) Barnyardgrass (Echinochloa crus-gralli) interference in soybeans (Glycine max). Weed Technol 7:220225
Walsh, MJ, Newman, P, Powles, SB (2013) Targeting weed seeds in-crop: a new weed control paradigm for global agriculture. Weed Technol 27:431436
Walsh, MJ, Powles, SB (2014) High seed retention at maturity of annual weeds infesting crop fields highlights the potential for harvest weed seed control. Weed Technol 28:486493
Ward, SM, Webster, TM, Steckel, LE (2013) Palmer amaranth (Amaranthus palmeri). Weed Technol 27:1227


Related content

Powered by UNSILO

Seed Retention of Palmer amaranth (Amaranthus palmeri) and Barnyardgrass (Echinochloa crus-galli) in Soybean

  • Lauren M. Schwartz-Lazaro (a1), Jeremy K. Green (a1) and Jason K. Norsworthy (a1)


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.