DIMETHOMORPH
IDENTIFICATION
Common name: Dimethomorph
Chemical abstracts name: (E,Z)-4-[3-(4-chlorophenyl)-3-(3,4-dimethoxyphenyl) -l-oxo-2-propenyl]morpholine
Type: Fungicide
CAS RN: [110488-70-5]
M.F.:C21H22CINO4
Mol Wt: 387.9
PHYSICAL CHEMISTRY
Form (appearance): Colourless crystals
Composition:: (E)- to (Z)- ratio is c. 1:1.
M.P.: 127-148℃; (E)- isomer 135.7-137.5℃; (Z)- isomer 169.2-170.2℃
V.P.: (E)- isomer 9.7 × 10-4 mPa; (Z)- isomer 1.0 × 10-3 mPa (both 25℃)
S.G.: Bulk density 1318 kg/m3 (20℃)
Solubility.: In water 19 (pH 5), 18 (pH 7), 16 (pH 9) (all in mg/l, 20℃). In acetone 88 (E), 15 (Z), cyclohexanone 27 (Z), dichloromethane 315 (Z), dimethylformamide 272 (E), 40 (Z), hexane 0.04 (E), 0.02 (Z), methanol 7 (Z), toluene 7 (Z) (all in g/l, 20-23 ℃). In n-hexane 0.11, methanol 39, ethyl acetate 48.3, toluene 49.5, acetone 100, dichloromethane 461 ( all for (EZ), in mg/l).
Stability: Hydrolytically and thermally stable under normal conditions. Stable for >5 years in the dark. The (E)- and (Z)- isomers are interconverted in sunlight
KowlogP: 2.63 (E)- isomer; 2.73 (Z)- isomer (both 20℃)
APPLICATION
Formulation types: DC; WG; WP.
Biochemistry: Inhibits the formation of the oomycete fungal cell wall
Mode of action: Local systemic fungicide with good protectant and antisporulant activity. Only the (Z)- isomer is intrinsically active, but, because of rapid interconversion of isomers in the light, it has no advantage over the (E)- isomer in practice
Uses: Fungicide effective against Oomycetes, especially Peronosporaceae and Phytophthora spp. (but not Pythium spp.) in vines, potatoes, tomatoes and other crops. Used in combination with contact fungicides, and applied at 2.0-2.5 kg dimethomorph/ha.
MAMMALIAN TOXICOLOGY
Oral: Acute oral LD50 for male rats 4300, female rats 3500, male mice >5000, female mice 3700 mg/kg b.w.
Skin and eye: Acute percutaneous LD50 for rats >5000 mg/kg b.w. Not irritant to skin or eyes of rabbits. Not a skin sensitiser (guinea pigs).
Inhalation: LC50 (4 h) for rats >4.2 mg/l air.
Noel: (2 y) for rats 200 mg/kg diet; (1 y) for dogs 450 mg/kg diet. Non-oncogenic in 2 y studies in rats and mice.
ADI: 0.09 mg/kg b.w.
Other Acute i.p. LD50 for male rats 327, female rats 297 mg/kg b.w.
Toxicity: WHO (a.i.) III (Table 5); EPA (formulation) III (`Acrobat MZ`)
ECOTOXICOLOGY
Birds: Acute oral LD50 for mallard ducks >2000 mg/kg. Dietary LC50 >5300 ppm.
Fish: LC50 (96 h) for bluegill sunfish >25, carp 14, rainbow trout 3.4 mg/l.
Daphnia: EC50 (48 h) 49 mg/l.
Algae: EC50 (96 h) >20 mg/l.
Worms: EC50 for earthworms >1000 mg/kg soil.
Bees: Non-toxic to honeybees at 0.1 mg/bee (contact or oral, highest dose tested).
ENVIRONMENTAL FATE
Plant: The only significant component of the residue, when present, is the parent compound.
Animals: In rats, the major route of metabolism is demethylation of one of the dimethoxy groups or by oxidation of one of the CH2 groups (ortho- or meta- position) of the morphotine ring. The major route of excretion was the faeces.
Soil/Environment: Moderately mobile (Kd 2-.09-11.67 ml/g, Koc 290-566). Aerobic soil metabolism DT50 66-117 d: no degradates identified except for CO2. |
