Triclopyr (3,5,6-trichloro-2-pyridinyloxyacetic acid) is an organic compound in the pyridine group that is used as a systemic foliar herbicide[2] and fungicide.[3]
| |
| |
| Names | |
|---|---|
| Preferred IUPAC name
[(3,5,6-Trichloropyridin-2-yl)oxy]acetic acid | |
| Other names
3,5,6-TPA; Trident (Agriphar)
| |
| Identifiers | |
3D model (JSmol)
|
|
| ChEBI | |
| ChemSpider | |
| ECHA InfoCard | 100.054.161 |
PubChem CID
|
|
| UNII | |
CompTox Dashboard (EPA)
|
|
| |
| |
| Properties | |
| C7H4Cl3NO3 | |
| Molar mass | 256.46 g·mol−1 |
| Appearance | Fluffy solid |
| Melting point | 148 to 150 °C (298 to 302 °F; 421 to 423 K) |
| 440 mg/L | |
| Solubility in acetone | 989 g/kg |
| Acidity (pKa) | 2.68 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
| |
Uses
editTriclopyr is a selective weedkiller used to control dicotyledonous weeds (i.e. broadleaf plants) while leaving monocotyledonous plants (mostly bulbs, grasses and conifers) unaffected,[2] or to control rust fungus on soybean crops.[3]
In the USA, it is sold under the trade names Garlon, Remedy, Turflon, Weed-B-Gon (purple label), Brush-B-Gon among others, and in the UK as SBK Brushwood Killer.
It is a major ingredient in Confront, which was withdrawn from most uses because of concerns about compost contamination from the other major ingredient, clopyralid.
Environmental effects
editTriclopyr breaks down in soil with a half-life between 30 and 90 days. It degrades rapidly in water, and remains active in decaying vegetation for about 3 months.[4]
The compound is slightly toxic to ducks (LD50 = 1698 mg/kg) and quail (LD50 = 3000 mg/kg).[5] It has been found nontoxic to bees and very slightly toxic to fish (rainbow trout LC50 (96 hr) = 117 ppm).[4]
Garlon's fact sheet for their triclopyr ester product indicates that triclopyr is highly toxic to fish, aquatic plants, and aquatic invertebrates, and should never be used in waterways, wetlands, or other sensitive habitats.[6] This is only for the triclopyr ester product, not for the triclopyr amine product.
References
edit- ^ Merck Index, 11th Edition, 9572.
- ^ a b Appleby, Arnold P.; Müller, Franz; Carpy, Serge (2001). "Weed Control". Ullmann's Encyclopedia of Industrial Chemistry. doi:10.1002/14356007.a28_165. ISBN 3-527-30673-0.
- ^ a b Shanmugasundaram, S.; Yeh, C.C.; Hartman, G.L.; Talekar, N.S. (1991). Vegetable Soybean Research Needs for Production and Quality Improvement (PDF). Taipei: Asian Vegetable Research and Development Center. pp. 86–87. ISBN 9789290580478. Retrieved 6 February 2016.
- ^ a b Environmental Fate Of Triclopyr, Carissa Ganapathy, Environmental Monitoring & Pest Management Branch Department of Pesticide Regulation Sacramento, CA (dead link 23 October 2023)
- ^ EXTOXNET (Extension Toxicology Network), Oregon State University
- ^ "Garlon XRT Herbicide" (PDF).