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Tolpyralate Efficacy: Part 2. Comparison of Three Group 27 Herbicides Applied POST for Annual Grass and Broadleaf Weed Control in Corn

  • Brendan A. Metzger (a1), Nader Soltani (a2), Alan J. Raeder (a3), David C. Hooker (a4), Darren E. Robinson (a4) and Peter H. Sikkema (a5)...


Tolpyralate is a new Group 27 pyrazolone herbicide that inhibits the 4-hydroxyphenyl-pyruvate dioxygenase enzyme. In a study of the biologically effective dose of tolpyralate from 2015 to 2017 in Ontario, Canada, tolpyralate exhibited efficacy on a broader range of species when co-applied with atrazine; however, there is limited published information on the efficacy of tolpyralate and tolpyralate+atrazine relative to mesotrione and topramezone, applied POST with atrazine at label rates, for control of annual grass and broadleaf weeds. In this study, tolpyralate applied alone at 30 g ai ha−1 provided >90% control of common lambsquarters, velvetleaf, common ragweed, Powell amaranth/redroot pigweed, and green foxtail at 8 weeks after application (WAA). Addition of atrazine was required to achieve >90% control of wild mustard, ladysthumb, and barnyardgrass at 8 WAA. Tolpyralate+atrazine (30+1,000 g ai ha−1) and topramezone+atrazine (12.5+500 g ai ha−1) provided similar control at 8 WAA of the eight weed species in this study; however, tolpyralate+atrazine provided >90% control of green foxtail by 1 WAA. Tolpyralate+atrazine provided 18, 68, and 67 percentage points better control of common ragweed, green foxtail, and barnyardgrass, respectively, than mesotrione+atrazine (100+280 g ai ha−1) at 8 WAA. Overall, tolpyralate+atrazine applied POST provided equivalent or improved control of annual grass and broadleaf weeds compared with mesotrione+atrazine and topramezone+atrazine.


Corresponding author

*Author for correspondence: Nader Soltani, Department of Plant Agriculture, University of Guelph Ridgetown Campus, Ridgetown, ON N0P 2C0, Canada. (Email:


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Abendroth, JA, Martin, AR, Roeth, FW (2006) Plant response to combinations of mesotrione and photosystem II inhibitors. Weed Technol 20:267274
Ahrens, H, Lange, G, Mueller, T, Rosinger, C, Willms, L, Almsick, AV (2013) 4-Hydroxyphenylpyruvate dioxygenase inhibitors in combination with safeners: solutions for modern and sustainable agriculture. Angew Chem Int Ed 44:93889398
Anonymous (2016) Armezon® Herbicide Label. Mississauga, ON, Canada: BASF Canada Inc.
Anonymous (2017) Tolpyralate® 400SC herbicide label. Concord, OH: ISK Biosciences Corporation
Armel, GR, Wilson, HP, Richardson, RJ, Hines, TE (2003) Mesotrione alone and in mixtures with glyphosate in glyphosate-resistant corn (Zea mays). Weed Technol 17:680685
Bollman, JD, Boerboom, CM, Becker, RL, Fritz, VA (2008) Efficacy and tolerance to HPPD-inhibiting herbicides in sweet corn. Weed Technol 22:666674
Cornes D (2005) Callisto: a very successful maize herbicide inspired by allelochemistry. Pages 569–572 in Proceedings of the 4th World Congress on Allelopathy. Wagga Wagga, NSW, Australia
Creech, JE, Monaco, TA, Evans, JO (2004) Photosynthetic and growth responses of Zea mays L. and four weed species following post-emergence treatments with mesotrione and atrazine. Pest Manag Sci 60:10791084
De Cauwer, B, Rombaut, R, Bulcke, R, Reheul, D (2012) Differential sensitivity of Echinochloa muricata and Echinochloa crus-galli to 4-hydroxyphenyl pyruvate dioxygenase- and acetolactate synthase-inhibiting herbicides in maize. Weed Res 52:500509
Grossman, K, Ehrhardt, T (2007) On the mechanism of action and selectivity of the corn herbicide topramezone: a new inhibitor of 4-hydroxyphenylpyruvate dioxygenase. Pest Manag Sci 63:429439
Hawkes, T (2012) Herbicides with bleaching properties. Hydroxyphenylpyruvate dioxygenase (HPPD): the herbicide target. Pages 225–232 in Modern Crop Protection Compounds. 2nd edn. Volume 1. Weinheim, Germany: Wiley-VCH
Health Canada (2018) Health Canada Public Registry–Product Information. Accessed: January 17, 2018
Hess, FD (2000) Light-dependent herbicides: an overview. Weed Sci 48:160170
Hugie, JA, Bollero, GA, Tranel, PJ, Riechers, DE (2008) Defining the rate requirements for synergism between mesotrione and atrazine in redroot pigweed (Amaranthus retroflexus). Weed Sci 56:265270
Johnson, BC, Young, BG (2002) Influence of temperature and relative humidity on the foliar activity of mesotrione. Weed Sci 50:157161
Johnson, BC, Young, BG, Matthews, JL (2002) Effect of postemergence application rate and timing of mesotrione on corn (Zea mays) response and weed control. Weed Technol 16:414420
Kaastra, AC, Swanton, CJ, Tardif, FJ, Sikkema, PH (2008) Two-way performance interactions among Hydroxyphenylpyruvate dioxygenase- and acetolactate synthase-inhibiting herbicides. Weed Sci 56:841851
Kikugawa, H, Satake, Y, Tonks, DJ, Grove, M, Nagayama, S, Tsukamoto, M (2015) Tolpyralate: new post-emergence herbicide for weed control in corn. Abstract 275 in Proceedings of the 55th Annual Meeting of the Weed Science Society of America. Lexington, KY: Weed Science Society of America
Kohrt, JR, Sprague, CL (2017) Response of a multiple-resistant Palmer amaranth (Amaranthus palmeri) population to four HPPD-inhibiting herbicides applied alone and with atrazine. Weed Sci 65:534545
Metzger, BA, Soltani, N, Raeder, AJ, Hooker, DC, Robinson, DE, Sikkema, PH (2018) Tolpyralate efficacy: Part 1. Biologically effective dose of tolpyralate for control of annual grass and broadleaf weeds in corn. Weed Technol (in press)
[OMAFRA] Ontario Ministry of Agriculture, Food and Rural Affairs (2016) Guide to Weed Control 2016–2017. OMAFRA Publication 75. Accessed: January 18, 2018
Pallet, KE, Cramp, SM, Little, JP, Veerasekaran, P, Crudace, AJ, Slater, AE (2001) Isoxaflutole: the background to its discovery and the basis of its herbicidal properties. Pest Manag Sci 57:133142
Rahman, A, Trolove, MR, James, TK (2013) Efficacy and crop selectivity of topramezone for post-emergence weed control in maize. Pages 470–476 in Proceedings of the 24th Asian-Pacific Weed Science Society Conference, Bandung, Indonesia
Stephenson, DO, Bond, JA (2012) Evaluation of thiencarbazone-methyl and isoxaflutole-based herbicide programs in corn. Weed Technol. 26:3742
Tonks, D, Grove, M, Kikugawa, H, Parks, M, Nagayama, S, Tsukamoto, M (2015) Tolpyralate: an overview of performance for weed control in US corn. Abstract 276 in Proceedings of the 55th Annual Meeting of the Weed Science Society of America. Lexington, KY: Weed Science Society of America
[USDA NASS] U.S. Department of Agriculture National Agricultural Statistics Service (2015) 2014 Agricultural Chemical Use Survey—Corn Highlights. Accessed: January 17, 2018
Whaley, CM, Armel, GR, Wilson, HP, Hines, TE (2006) Comparison of mesotrione combinations with standard weed control programs in corn. Weed Technol 20:605611
Williams, MM, Boydston, RA, Peachey, E, Robinson, D (2011) Significance of atrazine as a tank-mix partner with tembotrione. Weed Technol 25:299302
Woodyard, AJ, Bollero, GA, Riechers, DE (2009) Broadleaf weed management in corn utilizing synergistic postemergence herbicide combinations. Weed Technol 23:513518



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