Chemistry:Metamitron
Metamitron is an organic compound used as a pesticide.
It has been widely used in the European Union as a selective herbicide in sugar beets for weed suppression since the mid-1970's.[1][2][3]
In 2025, the U.S. EPA registered metamitron as a chemical, plant-growth regulator for thinning fruits for use on apple and pear trees.[4]
Chemical Structure and Mode of Action
Metamitron is a triazinone herbicide. It possesses a triazine ring like other organic compounds that use cyanuric chloride as a precursor. It is a modification of the chemical 1,2,4-triazin-5(4H)-one, with methyl, amino, and phenyl group substitutions at positions 3, 4, and 6.[5]
Metamitron is in the HRAC Mode of action Group 5.[6] It functions as an inhibitor of PSII by binding to serine 264 on the D1 protein.[7] Resistance to metamitron has been found in Chenopodium album growing as weeds among sugar beet fields in Belgium, caused by a mutation in serine 264.[2][7]
Metamitron is marketed by ADAMA under the trade name Goltix in Europe, the United Kingdom,[8] New Zealand, and South Africa; and as Brevis™ in the United States.[4]
Health and Environmental Impacts
Metamitron is very toxic to aquatic invertebrates, algae and to higher aquatic plants; and has a low expected acute and long-term toxicity-exposure risk for mammals and herbivorous birds.[9] In humans, metamitron has moderate acute oral and inhalation toxicity[5] and is an endocrine disruptor and may be a thyroid toxicant.[1] The major soil degradation product is desamino-metamitron.[9]
See also
References
- ↑ 1.0 1.1 "Metamitron". University of Hertfordshire. https://sitem.herts.ac.uk/aeru/ppdb/en/Reports/448.htm.
- ↑ 2.0 2.1 Mechant, Els (2011). Metamitron resistant Chenopodium album: characterisation, detection and distribution in Belgian sugar beet (Thesis). Ghent University. hdl:1854/LU-1898822. ISBN 978-90-5989-460-0.[page needed]
- ↑ Heri, Walter; Carroll, Beth; Parshley, Thomas; Nabors, James B. (2008). "Production, Development, and Registration of Triazine Herbicides". The Triazine Herbicides. pp. 31–43. doi:10.1016/B978-044451167-6.50006-4. ISBN 978-0-444-51167-6. "In the mid-1970s, Bayer launched metamitron under the trade name Goltix®. Metamitron has application timing flexibility and can be applied both preemergence and postemergence. One of the mainstays in sugar beet production, metamitron is currently sold in more than 25 countries, with the top five being Germany, France, Netherlands, United Kingdom/Ireland, and Belgium."
- ↑ 4.0 4.1 "Error: no
|title=specified when using {{Cite web}}". U.S. EPA. https://www.regulations.gov/docket/EPA-HQ-OPP-2022-0575/document. - ↑ 5.0 5.1 "Metamitron" (in en). https://pubchem.ncbi.nlm.nih.gov/compound/38854.
- ↑ "Global Herbicide Classification Lookup". https://hracglobal.com/tools/classification-lookup/?s=metamitron&mode=&letter=&number=#classificationLookup.
- ↑ 7.0 7.1 Thiel, Heike; Kluth, Christian; Varrelmann, Mark (September 2010). "A new molecular method for the rapid detection of a metamitron-resistant target site in Chenopodium album". Pest Management Science 66 (9): 1011–1017. doi:10.1002/ps.1975. PMID 20730994. Bibcode: 2010PMSci..66.1011T.
- ↑ "GOLTIX® 70 SC | ADAMA" (in en). 4 October 2021. https://www.adama.com/uk/en/our-solutions/herbicides/goltix-70-sc.
- ↑ 9.0 9.1 "Conclusion regarding the peer review of the pesticide risk assessment of the active substance metamitron". EFSA Journal (European Food Safety Authority) 6 (10). 29 September 2008. doi:10.2903/j.efsa.2008.185r. https://efsa.onlinelibrary.wiley.com/doi/pdf/10.2903/j.efsa.2008.185r. Retrieved 23 October 2025.
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