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
Picloram is a systemic herbicide used for general woody plant control. It also controls a wide range of broad-leaved weeds, but most grasses are resistant. ,
triclopyr
Triclopyr (3,5,6-trichloro-2-pyridinyloxyacetic acid) is an organic compound in the pyridine group that is used as a systemic foliar herbicide and fungicide.
Uses
Triclopyr is used to control broadleaf weeds while leaving grasses and conifers ...
, and several less common herbicides.
[Staff, Virginia Tech Cooperative Extension. Revised May 14, 201]
Pyridine Herbicide Carryover: Causes and Precautions
Accessed May 27, 2013 For control of creeping thistle, ''
Cirsium arvense
''Cirsium arvense'' is a perennial species of flowering plant in the family Asteraceae, native throughout Europe and western Asia, northern Africa and widely introduced elsewhere.Joint Nature Conservation Committee''Cirsium arvense'' The standa ...
'', 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.
It does not affect grasses (family
Poaceae).
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
Dow AgroSciences Limited liability company, LLC was a wholly owned subsidiary of the Dow Chemical Company specializing in not only agricultural chemicals such as pesticides, but also seeds and biotechnology solutions. The company was based in ...
, the manufacturer of clopyralid, voluntarily deregistered it for use on domestic lawns in the US 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 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,
Curtail, Confront, Clopyr AG, Lontrel, Millennium Ultra, Millenium Ultra Plus and Redeem.
References
{{Herbicides
Auxinic herbicides
Chloropyridines
Carboxylic acids