Identification of acetolactate synthase resistant Amaranthus retroflexus in Ukraine

  • L. M. Mykhalska Institute of Plant Physiology and Genetics of the National Academy of Sciences of Ukraine
  • V. V. Schwartau Institute of Plant Physiology and Genetics of the National Academy of Sciences of Ukraine
Keywords: weed control; herbicides; cross and multiple resistance; common amaranth; redroot pigweed; weed resistance management


The problem of weed resistance to herbicides has become very important in the last decade and threatens to dramatically reduce the productivity and profitability of modern crop production. Herbicides – ALS inhibitors dominate among current herbicides and are used annually on large areas of sunflower, wheat, corn, soybean, and rapeseed. Also, in recent years, Clearfield seeds of sunflower, corn, canola, soybean and wheat have been sown in large areas. In recent years, there has been a sharp decrease in Amaranthus retroflexus L. control levels by imidazolinone class herbicides. Thus, the effects of herbicides with different modes of action on the development of A. retroflexus on sunflower after imidazolinone application were investigated in field research. In the conditions of the Cherkasy region of Ukraine, the biotype A. retroflexus was identified, which is resistant to the post-emergence application of herbicides - acetolactate synthase (ALS) inhibitors of the imidazolinone class – imazapyr and imazamox. Weed plants treated with imidazolinone derivatives in the maximum doses registered in Ukraine did not differ from untreated control plants. Also, in the conditions of field experiments, cross resistance of the weed biotype to herbicides – ALS inhibitors of the sulfonylurea class – foramsulfuron and iodosulfuron-methyl-sodium, thifensulfuron-methyl, tribenuron-methyl, nicosulfuron was established; and also, to the triazolinone derivative – thiencarbazone-methyl; to triazolpyrimidine derivatives – florasulam and flumetsulam. Multiple resistance of the A. retroflexus biotype to herbicides of the classes of glycine derivatives – glyphosate, phenoxycarboxylates – 2,4-D, benzoic acid – dicamba has not been established; compositions of dicamba with triketone – topramesone; diphenyl ethers – aclonifen; pyridine carboxylates – clopyralid, picloram and aminopyralid. It was shown for the first time that herbicide compositions with selected nutrients (ammonium pool) can increase the level of effectiveness of controlling resistant weed biotypes. Thus, the addition of ammonium sulfate increases the effectiveness of controlling ALS-resistant A. retroflexus with herbicides – a derivative of benzoic acid (dianate) and a derivative of benzoic acid with a 4-hydroxyphenylpyruvate dioxygenase (HPPD) inhibitor (stellar – dicamba + topramesone). Thus, the A. retroflexus biotype resistant to ALS-herbicides of the imidazolinone class was identified for the first time in Ukraine, which is cross-resistant to other ALS-inhibitors of the sulfonylureas, triazolinones, and triazolpyrimidine classes. Multiple resistance of A. retroflexus to herbicides of the classes of glycine derivatives – glyphosate; phenoxycarboxylates – 2,4-D; benzoic acid – dicamba, triketones – topramesone; diphenyl ethers – aclonifen; pyridine carboxylates – clopyralid, picloram and aminopyralid has not been established. The identification of a highly harmful weed species resistant to widely used herbicides – ALS inhibitors in the central part of the "grain belt" of Ukraine requires a significant revision of the principles of crop rotation formation and ways of controlling weeds in the country in order to maintain high levels of profitability and productivity of agrophytocenoses.


Bakhshayeshan-Agdam, H., Salehi-Lisar, S. Y., Motafakkerazad, R., Talebpour, A., & Farsad, N. (2015). Allelopathic effects of redroot pigweed (Amaranthus retroflexus L.) on germination and growth of cucumber, alfalfa, common bean and bread wheat. Acta Agriculturae Slovenica, 105, 193–202.
Beckie, H. J., & Tardif, F. J. (2012). Herbicide cross resistance in weeds. Crop Protection, 35,15–28.
Burgos, N. R. (2015). Whole-plant and seed bioassays for resistance confirmation. Weed Science, 63(SP1), 152–165.
Chen, J., Huang, Z., Zhang, C., Huang, H., Wei, S., Chen, J., & Wang, X. (2015). Molecular basis of resistance to imazethapyr in redroot pigweed (Amaranthus retroflexus L.) populations from China. Pesticide Biochemistry Physiology, 124, 43–47.
Costea, M., Weaver, S. E., & Tardif, F. J. (2005). The biology of invasive alien plants in Canada. 3. Amaranthus tuberculatus (Moq.), Sauer var. rudis (Sauer), Costea & Tardif. Canadian Journal of Plant Science, 85(2), 507–522.
Dekker, J. H., & Duke, S. O. (1995). Herbicide-resistant field crops. Advances in Agronomy, 54(1), 69–116.
Duggleby, R. G., McCourt, J. A., & Guddat, L. W. (2008). Structure and mechanism of inhibition of plant acetohydroxyacid synthase. Plant Physiology and Biochemistry, 46(3), 309–324.
Duke, S. O. (2018). Herbicide-resistant crops: Agricultural, economic, environmental, regulatory, and technological aspects. CRC Press, Boca Raton.
Green, J. M. (2014). Current state of herbicides in herbicide-resistant crops. Pesticide Management Science, 70(9), 1351–1357.
Huang, Z., Chen, J., Zhang, C., Huang, H., Wei, S., Zhou, X., Chen, J., & Wang, X. (2016). Target-site basis for resistance to imazethapyr in redroot amaranth (Amaranthus retroflexus L.). Pesticide Biochemistry and Physiology, 128, 10–25.
Huang, Z., Cui, H., Wang, C., Wu, T., Zhang, C., Huang, H., & Wei, S. (2020). Investigation of resistance mechanism to fomesafen in Amaranthus retroflexus L. Pesticide Biochemistry and Physiology, 165, 104560.
Ivaschenko, O. O. (2013). Zeleni susidy [Green neighbors]. Fenyks, Kyiv (in Ukrainian).
Ivaschenko, O. O., & Ivaschenko, O. O. (2019). Zahalna herbolohiia [General herbology]. Fenyks, Kyiv (in Ukrainian).
Kistner, E. J., & Hatfield, J. L. (2018). Potential geographic distribution of palmer amaranth under current and future climates. Agricultural and Environmental Letters, 3(1), 170044.
Knezevic, S. Z., Horak, M. J., & Vanderlip, R. L. (1999). Estimates of physiological determinants for Amaranthus retroflexus. Weed Science, 47(3), 291–296.
Lindsey, L. E., Warncke, D. D., Steinke, K., & Everman, W. J. (2013). Fertilizer and population affects nitrogen assimilation of common lambsquarters (Chenopodium album) and redroot pigweed (Amaranthus retroflexus). Weed Science, 61(1), 131–135.
Milani, A., Scarabel, L., & Sattin, M. (2020). A family affair: Resistance mechanism and alternative control of three Amaranthus species resistant to acetolactate synthase inhibitors in Italy. Pesticide Management Science, 76(4), 1205–1213.
Mitich, L. W. (1997). Redroot pigweed (Amaranthus retroflexus). Weed Technology, 11(1), 199–202.
Mosyakin, S. (1995). Ohliad rodu Amaranthus L. (Amaranthaceae) v Ukrajini [Overview of the Amaranthus L. genus (Amaranthaceae) in Ukraine]. Ukrainian Botanical Journal, 52, 224–234 (in Ukrainian).
O’Sullivan, P. A., O’Donovan, J. T., & Hamman, W. M. (1981). Influence of non-ionic surfactants, ammonium sulfate, water quality and spray volume on the phytotoxicity of glyphosate. Canadian Journal of Plant Science, 61(2), 391–400.
Pline, W. A., Hatzios, K. K., & Hagood, E. S. (2000). Weed and herbicide-resistant soybean (Glycine max) response to glufosinate and glyphosate plus ammonium sulfate and pelargonic acid. Weed Technology, 14(4), 667–674.
Powles, S., & Yu, Q. (2010). Evolution in action: Plants resistant to herbicides. Annual Review of Plant Biology, 61(1), 317–347.
Scarabel, L., Varotto, S., & Sattin, M. (2007). A European biotype of Amaranthus retroflexus cross-resistant to ALS inhibitors and response to alternative herbicides. Weed Research, 47, 527–533.
Schwartau, V., & Mykhalska, L. (2013). Herbitsydy. Fizyko-khimichni ta biolohichni vlastyvosti [Herbicides. Physico-chemical and biological properties]. Lohos, Kyiv (in Ukrainian).
Sibony, M., & Rubin, B. (2003). The ecological fitness of ALS-resistant Amaranthus retroflexus and multiple-resistant Amaranthus blitoides. Weed Research, 43(1), 40–47.
Tan, S., Evans, R., Dahmer, M., Singh, B., & Shaner, D. (2005). Imidazolinone-tolerant crops: History, current status and future. Pesticide Management Science, 61(3), 246–257.
Turner, D., & Loader, M. (1975). Further studies with additives: Effects of phosphate esters and ammonium salts on the activity of leaf applied herbicides. Pesticide Science, 6, 1–10.
Wang, H., Wang, H., Zhao, N., Zhu, B., Sun, P., Liu, W., & Wang, J. (2019). Multiple resistance to PPO and ALS inhibitors in redroot pigweed (Amaranthus retroflexus). Weed Science, 68, 19–26.
Yu, Q., & Powles, S. B. (2014). Resistance to AHAS inhibitor herbicides: Current understanding. Pesticide Management Science, 70(9), 1340–1350.
How to Cite
Mykhalska, L. M., & Schwartau, V. V. (2022). Identification of acetolactate synthase resistant Amaranthus retroflexus in Ukraine. Regulatory Mechanisms in Biosystems, 13(3), 231-240. Retrieved from