ametryn

97%tech, 50%sc,

Herbicide

HRAC  C1 WSSA  5; 1,3,5-triazine

NOMENCLATURE

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) 

PHYSICAL CHEMISTRY

Composition 96% pure.  Mol. wt. 227.3  M.f. C9H17N5S  Form White powder.  M.p. 86.3-87.0 ºC  B.p. 337 °C/98.6 kPa  V.p. 0.365 mPa (25 ºC) (OECD 104)  KOW logP = 2.63 (25 ºC)  Henry 4.1 ´ 10-4 Pa m3 mol-1 (calc.)  S.g./density 1.18 (22 ºC)  Solubility In water 200 mg/l (20 ºC). In acetone 610, methanol 510, toluene 470, n-octanol 220, hexane 12 (all in g/l, 25 ºC).  Stability Stable in neutral, weakly acidic, and weakly alkaline media. Hydrolysed by strong acids (pH 1) and alkalis (pH 13) to the herbicidally-inactive 6-hydroxy derivative. Slowly decomposed by u.v. light.  pKa 4.1, weak base 

APPLICATIONS

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.