:Clopyralid
{{Chembox
| Verifiedfields = changed
| Watchedfields = changed
| verifiedrevid = 431582573
| Reference = Merck Index, 11th Edition, 2398.
| ImageFile = Clopyralid.png
| ImageSize = 160
| ImageClass = skin-invert
| ImageFile1 = Clopyralid-3D-spacefill.png
| ImageSize1 = 180
| ImageAlt1 = Adding space-filling model, adding alt text
| PIN = 3,6-Dichloropyridine-2-carboxylic acid
| OtherNames = 3,6-Dichloropicolinic acid
|Section1={{Chembox Identifiers
| Abbreviations = 3,6-DCP
| CASNo_Ref = {{cascite|correct|??}}
| CASNo = 1702-17-6
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 10G14M0WDH
| EINECS =
| SMILES = O=C(O)C1=C(Cl)C=CC(Cl)=N1
| PubChem = 15553
| ChemSpiderID_Ref = {{chemspidercite|changed|chemspider}}
| ChemSpiderID = 14797
| ChEMBL_Ref = {{ebicite|changed|EBI}}
| ChEMBL = 1650605
| SMILES1 = c1cc(nc(c1Cl)C(=O)O)Cl
| InChI = 1/C6H3Cl2NO2/c7-3-1-2-4(8)9-5(3)6(10)11/h1-2H,(H,10,11)
| InChIKey = HUBANNPOLNYSAD-UHFFFAOYAP
| StdInChI_Ref = {{stdinchicite|changed|chemspider}}
| StdInChI = 1S/C6H3Cl2NO2/c7-3-1-2-4(8)9-5(3)6(10)11/h1-2H,(H,10,11)
| StdInChIKey_Ref = {{stdinchicite|changed|chemspider}}
| StdInChIKey = HUBANNPOLNYSAD-UHFFFAOYSA-N
| RTECS =
| MeSHName =
| ChEBI_Ref = {{ebicite|correct|EBI}}
| ChEBI =
| KEGG_Ref = {{keggcite|correct|kegg}}
| KEGG = C18779
}}
|Section2={{Chembox Properties
| Formula = C6H3Cl2NO2
| MolarMass = 192.00
| Appearance = White crystalline solid
| Density =
| MeltingPtC = 150 to 152
| MeltingPt_notes =
| BoilingPt =
| BoilingPt_notes =
| Solubility = ~1000 ppm
| SolubleOther =
| Solvent =
| pKa =
| pKb =
}}
|Section7={{Chembox Hazards
| MainHazards =
| NFPA-H =
| NFPA-F =
| NFPA-R =
| NFPA-S =
| FlashPt =
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| ExploLimits =
| PEL =
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}}
Clopyralid (3,6-dichloro-2-pyridinecarboxylic acid) is a selective herbicide used for control of broadleaf weeds, especially thistles and clovers. Clopyralid is in the picolinic acid family of herbicides, which also includes aminopyralid, picloram, triclopyr, and several less common herbicides.Staff, Virginia Tech Cooperative Extension. Revised May 14, 2012 [http://pubs.ext.vt.edu/VTTP/VTTP-6/VTTP-6_pdf.pdf Pyridine Herbicide Carryover: Causes and Precautions] {{Webarchive|url=https://web.archive.org/web/20161130011248/http://pubs.ext.vt.edu/VTTP/VTTP-6/VTTP-6_pdf.pdf |date=2016-11-30 }} Accessed May 27, 2013Bob Hartzler, extension weed management specialist, Department of Agronomy, Iowa State University. February 21, 2006 [http://www.weeds.iastate.edu/mgmt/2006/aminopyralid.shtml Aminopyralid - New herbicide for pastures, roadsides, etc.] {{Webarchive|url=https://web.archive.org/web/20141103050326/http://www.weeds.iastate.edu/mgmt/2006/aminopyralid.shtml |date=2014-11-03 }} Accessed May 27, 2013 For control of creeping thistle, Cirsium arvense, a noxious, perennial weed, clopyralid is one of the few effective herbicides available. It is particularly damaging to peas, tomatoes, and sunflowers, and can render potatoes, lettuce, and spinach inedible.{{cite news | url=https://www.thetimes.com/world/us-world/article/weedkiller-banned-in-us-is-getting-into-compost-and-killing-garden-vegetables-cp60w9bszz7 | title=Weedkiller banned in US 'is getting into compost and killing garden vegetables' | newspaper=The Times | location=London | first=Oliver | last=Moody | date=23 February 2013}} It does not affect grasses (family Poaceae).{{Citation needed|date = December 2012}}
Clopyralid is known for its ability to persist in dead plants and compost, and has accumulated to phytotoxic levels in finished compost in a few highly publicized cases. This first came to light in Washington, when during 2000 and 2001, residues of clopyralid were detected in commercial compost, and compost made at a municipal site damaged tomatoes and other garden plants planted in it. Word quickly spread to other local and state governments, and in 2002, DowAgro, the manufacturer of clopyralid, voluntarily deregistered it for use on domestic lawns in the USDavid E. Haskell , California Department of Pesticide Regulation [http://www.cwss.org/proceedingsfiles/2003/045_2003.pdf Clopyralid in Compost]{{dead link|date=August 2017 |bot=InternetArchiveBot |fix-attempted=yes }} 2003 Proceedings of the California Weed Science Society 55:163-166 and it is banned in several US states, but it is found in consumer products in Europe such as Scotts Verdone Extra and Vitax Lawn Clear 2.
Clopyralid is used in Australia on industrial areas and agriculturally, to control broadleaf weeds in wheat, barley, oats, triticale, and fallow.{{cite web |title=4Farmers Clopyralid 300 |url=https://4farmers.com.au/products/herbicides/clopyralid-300/ |website=4farmers.com.au |publisher=4Farmers Australia}}
Clopyralid is licensed for lawn use in France and under these names:
Bayer Jardin: Désherbant jeune gazon and Scanner Sélectif gazon
Vilmorin: désherbant Gazon LONPAR.
Brand names of clopyralid in the US market include Stinger, Transline, Reclaim,{{cite web |url=http://www.weedscience.com/summary/ChemFamilySum.asp?lstActive=&btnSub1=Go&lstHRAC=24&btnSub2=Go |title=Herbicide Resistant Weeds |accessdate=2011-03-07 |url-status=dead |archiveurl=https://web.archive.org/web/20110718023102/http://www.weedscience.com/summary/ChemFamilySum.asp?lstActive=&btnSub1=Go&lstHRAC=24&btnSub2=Go |archivedate=2011-07-18 }} Curtail, Confront, Clopyr AG, Lontrel, Millennium Ultra, Millenium Ultra Plus and Redeem.