Triclopyr triethylamine salt was first reported in 1975 by Byrd
and coworkers. Triclopyr, also known by the trade name Garlon,
is an herbicide used extensively in the control of woody
plants and broadleaf weeds.
Triclopyr is an herbicide used to control woody plants and many
broadleaf weeds including rights-of-way, industrial areas,
forestry, railways, rangeland, home lawns, and permanent grass
pastures, rice, turf, and plantation crops such as palm oil. Triclopyr
triethylamine salt is a selective systemic herbicide that is
rapidly absorbed by the green bark, leaves, and roots and
distributed throughout the plant. Triclopyr accumulates in the
meristematic tissue (growth region) of the plant. Triclopyr is
formulated as triclopyr triethylamine (TEA) salt or triclopyr
butoxyethyl ester. Triclopyr is formulated as soluble and emulsifiable
concentrates, powders, pellets, granules, and liquids.
Colorless to amber liquid.
[(3,5,6-trichloro-2-pyridyl)oxy]acetic acid, compound with triethylamine (1:1) is incompatible with strong oxidizers.
Herbicide: A systemic herbicide used on rice, range land and
pasture, rights-of-way, forestry and grasslands, including
home lawns, for control of broadleaf weeds and woody
plant. Registered for use in EU countries
. Registered
for use in the U.S.
BRUSH-B-GON®; CONFRONT®;
CROSSBOW®; DOWELANCO® BRUSH AND WEED;
DTDA/DMA-TEA-DMA® SELECTIVE HERBICIDE;
GARLON-3A®; GRANDSTAND®; MON® 78736;
REDEEM® R & P; RENOVATE®; RIVERDALE
DTDA® SELECTIVE HERBICIDE; RIVERDALE
HORSEPOWER®; TRICLOPRY-EZ-JECT®; TURFLON®
AMINE; XRM-5202®; WEEDEX®
Triclopyr TEA is a grayish white granular solid. It is miscible
in water, slightly soluble in toluene and ethyl acetate, and
practically insoluble in hexane. The Henry’s law constant is
1.15 × 10-14 atm-m3 mol-1; octanol/water partition coefficient
is <5 (1.23).
Air
Volatilization of triclopyr TEA occurs slightly due to its lower
vapor pressure. Low Henry’s law constant indicates little escaping tendency from an aqueous solution. Triclopyr is not
found in air with the exception of spray drift and dust from
pesticide application.
Water
Triclopyr TEA is degraded by photodegradation in water. It is
highly water soluble and dissociates to the weak acid triclopyr
acid and triethanolamine. Triethanolamine rapidly degrades to
CO2 by aerobic microbial processes (half-life 14–18 days).
However, triethanolamine does not degrade under anaerobic
aquatic conditions (half-life >2 years). Triclopyr acid further
dissociates to triclopyr anion, which is the predominant moiety
in the environment. The photolysis of triclopyr acid in aqueous
media is rapid and the half-life is approximately 1 day in water.
The major photolyzed products of triclopyr acid observed were
5-chloro-3,6-dihydroxy-2-pyridinoloxyacetic acid and oxamic
acid in water.
Soil
The major route of dissipation in soil is through microbial
degradation. Moisture favors the microbial growth, which in
turn increases microbial activity. The triclopyr acid is degraded
primarily by microbes with half-lives of 8–18 days to intermediate
compounds 3,5,6-trichloro-2-pyridinol (TCP) and
3,5,6-trichloro-2-methoxypyridine (TMP), and CO2. Triclopyr,
TMP, and TCP have lower soil mobility due to which there
might be limited leaching.
There is no evidence on bioaccumulation of triclopyr in fish
or aquatic nontarget microorganisms.
The mechanism of action of triclopyr in mammals is still
unclear, although its mechanism of toxicity in plants is well documented. The triclopyr exerts its toxicity in plants by
mimicking the effect of plant growth hormones, which is
similar to its pyridine analog 2,4,5-trichlorophenoxy acetic
acid. Histopathology and clinical chemistry laboratory data
suggest that the liver and kidneys are the primary target organs.
Like any chemical, triclopyr can cause lethality at very high
doses. Triclopyr is excreted primarily through kidneys by a welldefined
active transport process. This process may become
impeded and saturated at very high doses.