Metribuzin 嗪草酮

嗪草酮

简介
英文通用名 metribuzin
其他名称 赛克津、赛克(Sencor)、立克除(Lexone)，Beyer94337，甲草嗪。
化学名称： 4-氨基-6-(1,1-二甲基乙基)-3-甲硫基-1,2,4-三嗪-5-四氢酮。 嗪草酮的结构式

毒性
对人畜低毒。大鼠口服急性LD50为1100-2300毫克/公斤，大鼠急性经皮LD50>20000毫克/公斤。慢性毒性试验未见异常。两年饱喂对狗和大鼠无作用剂量为100毫克/公斤。对鱼类及水生物、鸟类、蜜蜂均低毒。
剂型 50%、70%可湿性粉剂，75%干悬浮剂。

特点
是内吸选择性除草剂，主要通过根吸收、茎、叶也可吸收。对1年生阔叶杂草和部分禾本科杂草有良好防除效果，对多年生杂草无效。药效受土壤类型、有机质含量多少、湿度、温度影响较大，使用条件要求较严，使用不当，或无效，或产生药害。
适用范围 适用于大豆、马铃薯、番茄、苜蓿、芦笋、甘蔗等作物田防除蓼、苋、藜、芥菜、苦荬菜、繁缕、荞麦蔓、香薷、黄花蒿、鬼针草、狗尾草、鸭跖草、苍耳、龙葵、马唐、野燕麦等1年生阔叶草和部分1年生禾本科杂草。

使用方法
1.大豆田使用 春大豆播种后出苗前，每亩用70%可湿性粉剂53-76克，对水30公斤左右，均匀喷布土表。夏大豆播后出苗前，每亩用70%可湿性粉剂33-57克，处理同春大豆。
2.马铃薯田使用 播种后出苗前使用，每亩用70%可湿性粉剂66-76克，对水30公斤，均匀喷布土表，出苗后使用，一般在马铃薯株高10cm以上时，耐药性下降，易产生药害。

注意事项
1.大豆田只能苗前使用，苗期使用有药害。
2.有机质含量低于2%以下的沙质土壤不宜使用。
3.气温高有机质含量低的地区，施药量用低限，相反用高限。
4.对下茬或隔后茬白菜、豌豆之类有药害影响，注意使用时期的把握。

metribuzin
Herbicide
HRAC C1 WSSA 5; 1,2,4-triazinone

NOMENCLATURE
Common name metribuzin (BSI, E-ISO, WSSA); métribuzine ((f) F-ISO)
IUPAC name 4-amino-6-tert-butyl-4,5-dihydro-3-methylthio-1,2,4-triazin-5-one; 4-amino-6-tert-butyl-3-methylthio-1,2,4-triazin-5(4H)-one
Chemical Abstracts name 4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one
CAS RN [21087-64-9] EEC no. 244-209-7 Development codes Bayer 94 337; DIC 1468 (both Bayer); DPX-G2504 (DuPont)

PHYSICAL CHEMISTRY
Mol. wt. 214.3 M.f. C8H14N4OS Form White crystals, with a weak characteristic odour. M.p. 126.2 ºC B.p. 132 ºC/2 Pa. V.p. 0.058 mPa (20 ºC) KOW logP = 1.6 (pH 5.6, 20 ºC) Henry 1 ´ 10-5 Pa m3 mol-1 (20 °C, calc.) S.g./density 1.13 (20 ºC) Solubility In water 1.05 g/l (20 ºC). In dimethylformamide 1780, cyclohexanone 1000, chloroform 850, acetone 820, methanol 450, dichloromethane 333, benzene 220, n-butanol 150, ethanol 190, toluene 87, xylene 90, isopropanol 77, hexane 0.1-1.0 (all in g/l, 20 ºC). Stability Relatively stable to u.v. irradiation. At 20 ºC, stable to dilute acids and alkalis; DT50 (37 ºC) 6.7 h (pH 1.2); DT50 (70 ºC) 569 h (pH 4), 47 d (pH 7), 191 h (pH 9). Photodecomposition in water is very rapid (DT50 <1 d). On soil surfaces under natural light conditions, DT50 14-25 d.

COMMERCIALISATION
History Herbicide reported by W. Draber et al. (Naturwissenschaften, 1968, 55, 446) and reviewed by L. Eue (Pflanzenschutz-Nachr. (Engl. Ed.), 1972, 25, 175). Introduced by Bayer AG and E. I. du Pont de Nemours and Co., and first marketed in 1971. Patents BE 697083, DE 1795784 both to Bayer; US 3905801 to Du Pont Manufacturers Bayer CropScience; DuPont; Feinchemie Schwebda; Rallis

APPLICATIONS
Biochemistry Photosynthetic electron transport inhibitor at the photosystem II receptor site. Selectivity is due to metabolism (mostly conjugation) within the plant (C. Fedtke, Proc. Br. Crop Prot. Conf. - Weeds, 1993, 1, 221). Mode of action Selective systemic herbicide, absorbed predominantly by the roots, but also by the leaves, with translocation acropetally in the xylem. Uses Pre- and post-emergence control of many grasses and broad-leaved weeds in soya beans, potatoes, tomatoes, sugar cane, alfalfa, asparagus, maize and cereals, at 0.07-1.45 kg/ha. Phytotoxicity Phytotoxic to many crops, including crucifers, cucurbits, lettuce, onions, sugar beet, sunflowers, flax, strawberries, sweet potatoes, and tobacco. Formulation types SC; WG; WP. Compatibility Compatible with most other herbicides, except in highly concentrated mixtures. Selected products: 'Lexone' (DuPont); 'Aliso' (Cequisa); 'Hilmetri' (Hindustan); 'Major' (Crop Health); 'Metiroc' (Rocca); 'Mistral' (Feinchemie Schwebda); 'Sencor' (Bayer CropScience); 'Vapcor' (Vapco); mixtures: 'Axiom' (+ flufenacet) (Bayer CropScience); 'Domain' (+ flufenacet) (Bayer CropScience)

OTHER PRODUCTS
'Citation' (United Phosphorus Ltd); 'Feinzin' (Feinchemie Schwebda); 'Pataprop' (Hermoo); 'Premercas' (CAS); 'Python' (Feinchemie Schwebda); 'Sencoral' (in France) (Bayer CropScience); 'Sencorex' (in Great Britain) (Bayer CropScience); 'Valtor' (IQV) mixtures: 'Canopy' (+ chlorimuron-ethyl) (DuPont); 'Pilar' (+ rimsulfuron) (DuPont); 'Preview' (+ chlorimuron-ethyl) (DuPont); 'Artist' (+ flufenacet) (Bayer CropScience); 'Authority BL' (+ sulfentrazone) (FMC); 'Axiom AT' (+ atrazine+ flufenacet) (Bayer CropScience); 'Bastille' (+ flufenacet) (Bayer CropScience); 'Boundary' (+ S-metolachlor) (Syngenta); 'Draeda' (+ flufenacet) (Bayer CropScience); 'Fedor' (+ flufenacet) (Bayer CropScience); 'Galice' (+ amidosulfuron) (Bayer CropScience); 'Plateen' (+ flufenacet) (Bayer CropScience); 'Salute' (+ trifluralin) (Bayer CropScience); 'Segal' (+ amidosulfuron) (Bayer CropScience); 'Top Gun' (+ 2,4-D) (Platte) Discontinued products mixtures: 'Turbo' * (+ metolachlor) (Bayer)

ANALYSIS
Product analysis by glc with FID (AOAC Methods, 17th Ed., 984.11; CIPAC Handbook, 1988, D, 137) or by i.r. spectrometry (J. W. Betker et al., J. Assoc. Off. Anal. Chem., 1976, 59, 278). Residues determined by glc (C. A. Anderson, Anal. Methods Pestic. Plant Growth Regul., 1976, 8, 453). In drinking water, by glc with NPD (AOAC Methods, 17th Ed., 991.07); metabolites by lc with u.v. detection (ibid., 1995, 992.14). Details available from Bayer CropScience.

MAMMALIAN TOXICOLOGY
Reviews Toxikologie der Herbizide, Deutsche Forschungsgemeinschaft [Data collection on toxicology of herbicides], 7. Lieferung, Weinheim, 1981. Oral Acute oral LD50 for male rats 510, female rats 322, mice c. 700, guinea pigs c. 250, cats >500 mg/kg. Skin and eye Acute percutaneous LD50 for rats >20 000 mg/kg. Not irritating to skin and eyes (rabbits). Inhalation LC50 (4 h) for rats >0.65 mg/l air (dust). NOEL (2 y) for rats and dogs 100, mice c. 800 mg/kg diet. ADI 0.013 mg/kg b.w. Toxicity class WHO (a.i.) II; EPA (formulation) III EC classification Xn; R22| N; R50, R53

ECOTOXICOLOGY
Birds Acute oral LD50 for bobwhite quail 164, mallard ducks 460-680 mg/kg. Fish LC50 (96 h) for rainbow trout 74.6, golden orfe 141.6, sheepshead minnow 85 mg/l. Daphnia LC50 (48 h) 49.6 mg/l. Algae ErC50 for Scenedesmus subspicatus 0.021 mg/l. Bees Not toxic to bees; LD50 35 mg/bee. Worms LC50 for Eisenia foetida 331.8 mg/kg dry soil.

ENVIRONMENTAL FATE
Animals In mammals, following oral administration, 98% elimination occurs within 96 hours, about equally in the urine and the faeces. Plants In plants, metribuzin undergoes oxidative deamination and further degradation to water-soluble conjugates. Soil/Environment Rapidly degraded in soil; microbial breakdown is the major mechanism of loss; losses due to photodecomposition or volatilisation are insignificant; DT50 in soil c. 1-2 months; DT50 in pond water c. 7 d. Degradation involves deamination, followed by further degradation to water-soluble conjugates.