Products >> Herbicides >> Ametryn
Ametryn 95%TC, Ametryn 50%SC, Ametryn 90%WDG
HRAC C1 WSSA 5; 1,3,5-triazine
Common name ametryn (BSI (since 1984), E-ISO, ANSI, WSSA, JMAF);
ametryne (BSI (before 1984), (f) F-ISO)
IUPAC name N2-ethyl-N4-isopropyl-6-methylthio-1,3,5-triazine-2,4-diamine
Chemical Abstracts name N-ethyl-N'-(1-methylethyl)-6-(methylthio)-1,3,5-triazine-2,4-diamine
CAS RN [834-12-8] EEC no. 212-634-7 Development codes G 34 162 (Geigy)
Biochemistry Photosynthetic electron transport inhibitor at the
photosystem II receptor site. Mode of action Selective systemic
herbicide, absorbed by the leaves and roots, with translocation
acropetally in the xylem, and accumulation in the apical meristems.
Uses Pre- and post-emergence control of most annual grasses and
broad-leaved weeds in pineapples, sugar cane, bananas, citrus fruit,
maize, cassava, coffee, tea, sisal, cocoa, oil palms, and on non-crop
land. Application rates are in the range 2-4 kg/ha, except when
used as a directed spray on maize. Also used as a potato haulm desiccant.
Phytotoxicity Some sugar cane varieties show temporary chlorosis
and scorching of lower leaves. Formulation types EC; FW; SC; WG;
WP. Selected tradenames: 'Evik' (USA) (Syngenta); 'Gesapax' (Syngenta);
'Ameflow' (Inquiport); 'Amesip' (Sipcam); 'Ametrex' (Makhteshim-Agan);
'Mebatryne' (Aventis); mixtures: 'Krismat' (+ trifloxysulfuron)
(trifloxysulfuron as sodium salt) (Bayer)
Ametryn OTHER TRADENAMES
'Crisatrina' (Crystal) mixtures: 'Codal' (+ prometryn) (Syngenta);
'Amigan' (+ terbutryn) (Makhteshim-Agan); 'Atramet Combi' (+ atrazine)
Product analysis by glc with FID (CIPAC Handbook, 1980, 1A, 1102;
FAO Specification CP/61; AOAC Methods, 1995, 971.08). Residues determined
by glc (K. Ramsteiner et al., J. Assoc. Off. Anal. Chem., 1974,
57, 192; E. Knüsli, Anal. Methods Pestic. Plant Growth Regul.
Food Addit., 1964, 4, 13; B. G. Tweedy & R. A. Kahrs, Anal.
Methods Pestic. Plant Growth Regul., 1978, 10, 493). In drinking
water, by gc with FID; AOAC Methods, 1995, 991.07.
Reviews J. Pest. Sci., 18(4), 1993 (in Japanese). Oral Acute oral
LD50 for rats 1160 mg tech./kg. Skin and eye Acute percutaneous
LD50 for rabbits >2020, rats >3100 mg/kg. Not a skin or eye
irritant (rabbits). Not a skin sensitiser (guinea pigs). Inhalation
LC50 (4 h) for rats >5170 mg/m3 air. NOEL (2 y) for rats 50,
for mice 10 ppm; (1 y) for dogs 200 ppm. ADI 0.015 mg/kg daily.
Toxicity class WHO (a.i.) III; EPA (formulation) III EC hazard Xn;
R22| N; R50, R53
Birds LC50 (5 d) for bobwhite quail and mallard ducks >5620 ppm.
Fish LC50 (96 h) for rainbow trout 5, bluegill sunfish 19, channel
catfish 25 mg/l. Daphnia LC50 (96 h) 28 mg/l. Algae EC50 (7 d) for
Selenastrum capricornutum 0.0036 mg/l. Other aquatic spp. LC50 (96
h) for mysid shrimp (Mysidopsis bahia) 2.3 mg/l. Bees Low toxicity
to bees; LD50 (oral) >100 mg/bee. Worms LC50 (14 d) for earthworms
166 mg/kg soil.
Animals Irrespective of the dose or the dosing regime, most is excreted
within 3 to 4 days. Conjugation with glutathione and dealkylation
are the main metabolic pathways. Plants Metabolised by tolerant
plants and, to a lesser extent, by sensitive plants, to non-toxic
substances by replacement of the methylthio group by a hydroxy group,
and by dealkylation of the amino groups. Soil/Environment Loss from
soil is principally by microbial degradation (H. O. Esser et al.,
Herbicides: Chemistry, Degradation and Mode of Action, 1975, 1,
129). Median DT50 in soil 51 d (11-120 d). Koc 300; however column
leaching studies indicate ametryn does not leach significantly.
Degradation in aquatic systems is caused by microbial processes,
with photolysis also contributing. Adsorption to the sediment is
the most efficient mechanism of elimination of ametryn from water.