Zineb 代森锌

代森锌

基本介绍
别名：乙撑双(二硫代氨基甲酸锌);代森锌可湿性粉剂
分子式：C4H6N2S4Zn
分子量：276.7802
用途：叶面用保护性杀菌剂，主要用于防治麦类、蔬菜、葡萄、果树和烟草等作物的多种真菌病害
代森锌为保护性有机硫杀菌剂。纯品为灰白色粉末，工业品为灰白色或淡黄色粉末，有硫磺气味。在碱性、高温、潮湿、日光照晒条件下不稳定。对人畜低毒，但对人的皮肤、鼻、咽喉有刺激作用。对植物安全无污染。 主要剂型60%、65%和80%可湿性粉剂，4%粉剂。
白色粉末，157℃分解，无熔点。蒸气压<0.0lmPa(20℃)。室温水中溶解度为10mg/L，不溶于大多数有机溶剂，但能溶于吡啶。对光、热、湿气不稳定，易分解，遇碱性物质或含铜、汞的物质，也易分解。大鼠急性经口毒性LD50 5200mg/kg以上。在乙二胺溶液中，滴加二硫化碳、氢氧化钠，生成代森钠溶液后，在pH值6.5条件下加硫酸锌(或氯化锌)，即制得本品。
可防治白菜、黄瓜霜霉病，番茄炭疽病，马铃薯晚疫病，葡萄白腐病、黑斑病，苹果、梨黑星病等。制剂有80%可湿性粉剂。能阻止各种微生物的发育。

作用及使用方法
代森锌能防治多种真菌引起的病害，但对白粉病作用差。代森锌
（l）防治马铃薯早疫病、晚疫病，西红柿早疫病、晚疫病、斑枯病、叶霉病、炭疽病、灰霉病，茄子绵疫病、褐纹病，白菜、萝卜、甘蓝霜霉病、黑斑病、白斑病、软腐病、黑腐病，瓜类炭疽病、霜霉病、疫病、蔓枯病、冬瓜绵疫，豆类炭疽病、褐斑病、锈病、火烧病等，用65%的代森锌可湿性粉剂500－700倍液喷雾。喷药次数根据发病情况而定，一般在发病前或发病初期开始喷第1次药，以后每隔7一10天喷1次，速喷2-3次。
（2）防治蔬菜苗期病害，可用代森锌和五氯硝基苯做成"五代合剂"处理土壤。即用五氯硝基苯和代森锌等量混合后，按每平方米育苗床面用混合制剂8-10克。用前将药剂与适量的细土混匀；取三分之一药土撒在床面做垫土，播种后用剩下的三分之二药土作播后覆盖土用，而后用塑料薄膜覆盖床面，保持床面湿润，直到幼苗出土揭膜。
（3）防治白菜霜霉病，蔬菜苗期病害，可用种子重量的0．3－0．4%进行药剂拌种。

注意事项
（1）葫芦科蔬菜对锌敏感，用药时要严格掌握浓度，不能过大。
（2）不能与碱性农药混用。
（3）本品受潮、热易分解，应存置阴凉干燥处，容器严加密封。
（4）使用时注意不让药液溅入眼、鼻、口等，用药后要用肥皂洗净脸和手

zineb
Fungicide
FRAC M3; multi-site: alkylenebis(dithiocarbamate)

NOMENCLATURE
Common name zineb (BSI, E-ISO, JMAF); zinèbe ((m) F-ISO); no name (Germany)
IUPAC name zinc ethylenebis(dithiocarbamate) (polymeric)
Chemical Abstracts name [[1,2-ethanediylbis[carbamodithioato]](2-)]zinc
CAS RN [12122-67-7] EEC no. 235-180-1 Official codes ENT 14 874

PHYSICAL CHEMISTRY
Mol. wt. 275.8 M.f. C4H6N2S4Zn Form Pale yellow powder. M.p. Decomposes at 157 ºC without melting V.p. <0.01 mPa (20 ºC) KOW logP £1.3 (20 ºC) Henry <2.76 ´ 10-4 Pa m3 mol-1 (calc.) Solubility In water c. 10 mg/l (room temperature). Practically insoluble in common organic solvents. Dissolves in some chelating agents, for example salts of ethylenediaminetetra-acetic acid, from which it cannot be recovered. Stability Unstable to light, moisture and heat on prolonged storage (decomposition is reduced by stabilisers). When precipitated from concentrated solution, a polymer is formed which is less fungicidal. F.p. 90 ºC; autoignition temperature 149 ºC

COMMERCIALISATION
History J. M. Heuberger & T. F. Manns (Phytopathology, 1943, 33, 113) reported the addition of zinc sulfate improved the field performance of nabam as a fungicide. This led to the introduction of zineb by Rohm & Haas Co. (now Dow AgroSciences), and by E. I. du Pont de Nemours and Co., (who no longer manufacture or market it). Patents US 2457674; US 3050439 Manufacturers Bayer CropScience; Cerexagri; Indofil

APPLICATIONS
Biochemistry Non-specific thiol reactant, inhibiting respiration. Mode of action Foliar fungicide with protective action. Uses Control of downy mildews in vines, hops, lettuce, onions, spinach, brassicas, oilseed rape, tobacco, and ornamentals; rusts in currants, berry fruit, plums, vegetables, and ornamentals (especially carnations and chrysanthemums); red fire disease on vines; potato and tomato blights; leaf spot diseases on currants, berry fruit, olives, and celery; anthracnose on beans, vines, and citrus fruit; scab on apples and pears; shot-hole on stone fruit; Cercospora on bananas; tulip fire; Botrytis; needle cast in forestry; etc. Phytotoxicity Non-phytotoxic, except for zinc-sensitive plants such as tobacco and cucurbits. Formulation types DP; WP. Compatibility Incompatible with alkaline or mercury-containing compounds. Selected products: 'Amitan' (Sipcam); 'Indofil Z-78' (Indofil); 'Peran' (Efthymiadis); 'Phytox' (Stähler); 'Tritoftorol' (Cerexagri); 'Vitex' (Siapa); mixtures: 'Vizines' (+ sulfur) (Vipesco)

OTHER PRODUCTS
'Dithane Z-78' (Dow AgroSciences); 'Sepineb' (DuPont); 'AAphytora' (Bayer CropScience); 'Azzurro' (Chemiplant); 'Bianco' (Chemiplant); 'Dipher' (Kumiai); 'Polyram-Z' (BASF); 'Zinugec' (Sipcam Phyteurop) mixtures: 'Cupro Phynebe' (+ copper oxychloride) (France) (Bayer CropScience); 'Vizincop' (+ copper oxychloride) (Vipesco) Discontinued products: 'Parzate' * (DuPont); 'Lonacol' * (Bayer) mixtures: 'Bordeaux MZ' * (+ Bordeaux mixture+ maneb) (Nufarm Americas); 'Trimanzone WP' * (+ ferbam+ maneb) (Intracrop)

ANALYSIS
Product analysis by acid hydrolysis, converting the carbon disulfide evolved into dithiocarbonate which is estimated by titration with iodine (CIPAC Handbook, 1992, E, 230-235; ibid., 1998, H, 100; AOAC Methods, 17th Ed., 965.15) or by liberation of arsenic which is determined spectrophotometrically (CIPAC Handbook, 1992, E, 231). Identified colorimetrically (CIPAC Handbook, 1994, F, 320) or by u.v. absorbance (ibid., p. 411). ETU content by hplc with u.v. detection, or by paper chromatography (ibid., 1994, F, 399). Determination of zinc ibid., 1994, F, 235. Residues determined by acid hydrolysis, measuring the carbon disulfide evolved using glc (Analyst (London), 1981, 106, 782) or by conversion to a copper/amine complex which is estimated by colorimetry (Pestic. Anal. Man., 1979, II; Manu. Pestic. Residue Anal., 1987, I, S21; Anal. Methods Residues Pestic., 1988, Part II; W. K. Lowen & H. L. Pease, Anal. Methods Pestic., Plant Growth Regul. Food Addit., 1964, 3, 69).

MAMMALIAN TOXICOLOGY
Reviews FAO/WHO 68, 70 (see part 2 of the Bibliography). IARC ref. 12 class 3 Oral Acute oral LD50 for rats >5200 mg/kg. Skin and eye Acute percutaneous LD50 for rats >6000 mg/kg. Slight irritation of skin and mucous membranes. NOEL In feeding trials, growth was inhibited in rats within 74 w at 10 000 mg/kg diet. ADI (JMPR) 0.03 mg/kg b.w. (group ADI with mancozeb, maneb and metiram); ethylenethiourea 0.004 mg/kg b.w. [1993]. Other At very high doses, ethylenethiourea, a trace contaminant and breakdown product of zineb, has caused thyroid effects, tumours and birth defects in laboratory animals. Toxicity class WHO (a.i.) U; EPA (formulation) IV EC classification Xi; R37| R43

ECOTOXICOLOGY
Fish LC50 for perch 2, roach 6-8 mg/l. Bees Not toxic to bees.

ENVIRONMENTAL FATE
EHC 78 (WHO, 1988; general review of dithiocarbamates). Plants Ethylenethiourea is the major metabolite in plants. Ethylenethiuram monosulfide and presumably ethylenethiuram disulfide and sulfur are also formed.