溴甲烷在草莓田的替代及减少其散发的技术

溴甲烷是一种消耗臭氧层的物质，根据《蒙特利尔议定书哥本哈根修正案》，发展中国家将于2015年淘汰。在我国溴甲烷消费量最大的地区，河北省满城县实施了中-意“溴甲烷土壤消毒替代技术及能力建设项目”。试验结果表明：威百亩和威百亩＋VIF，采用化学灌溉技术施药，是有前景的溴甲烷替代品，2001～2002年威百亩和威百亩＋VIF处理“达赛莱克特”品种的产量分别为26816kg／hm^2和23672kg／hm^2，而溴甲烷处理的产量为28346kg／hm^2；威百亩和威百亩＋VIF处理“理念”品种的产量分别为19844kg／hm^2和15989kg／hm^2而溴甲烷处理的产量为19657kg／hm^2；2002～2003年威百亩和威百亩＋VIF处理“达赛莱克特”品种的产量分别为23073kg／hm^223446kg／hm^2而溴甲烷处理的产量为25285kg／hm^2威百亩和威百亩＋VIF处理“全明星”品种的产量分别为：29594kg／hm^227677kg／hm^2而溴甲烷处理的产量为32191kg／hm^2产量结果经统计分析表明，威百亩、威百亩＋VIF与溴甲烷均无显著差异。溴甲烷＋VIF采用热法施药，其产量与溴甲烷无明显差异，但溴甲烷＋VIF能减少溴甲烷25％的用药量。太阳能消毒＋生物防治制剂的产量高于空白对照，有一定的防病增产效果，但显著低于溴甲烷处理的产量，不能作为溴甲烷的替代品。进口品种“理念”和当地主栽品种“全明星”对土传病害的抗性较差，在长势、产量方面均显著差于新引进品种“达赛莱克特”。虽然“达赛莱克特”对土传病害有一定的抗性，但与溴甲烷和威百亩处理区比较，空白对照区的产量仍显著低于药剂处理区的产量。     

溴甲烷在番茄土壤消毒中替代技术研究

采用保护地内划分小区实验方法，在番茄载培过程中，研究了代替溴甲烷的其它3种消毒技术，结果表明，生物熏蒸，人工基质和阿维菌素对防治根结线虫都有不同的效果，增产幅度分别为18．9％，14．05％，19．0％，同时嗅甲烷土壤消毒增产22．06％。从直接经济效益看，阿维菌素＞生物熏蒸＞溴甲烷＞人工基质。     

溴甲烷土壤熏蒸技术在秋季温室番茄应用的研究初报

在夏秋高温季节,采用溴甲烷土壤熏蒸技术,可有效地防治温室番茄的土传病害和增加番茄产量,用药剂量为２５ｇ／ｍ２、５０ｇ／ｍ２、７５ｇ／ｍ２的条件下,其对番茄枯萎病的防治效果可达６８．７７％、８７．４９％、９３．７４％,对根结线虫病的防效可达８２．８５％、９２．５２％、９７．１５％,番茄增产幅度可达１４．４％、２３．９％、２９．２％。     

硫酰氟——溴甲烷土壤消毒潜在的替代品

初步试验表明,硫酰氟25~50 g/m2对土壤真菌(Fusarium sp.)、线虫均有良好的杀灭效果,防治后番茄产量与使用溴甲烷50 g/m2相当。硫酰氟蒸汽压高,穿透性强,可杀死深土层中的线虫及病原菌。由于其在常温下是气体,即使在冬天使用,也不需要搭小拱棚或采用"热法"施药,因此比使用溴甲烷更为方便;使用时也不像威百亩那样需要专用的施药设备。因此,硫酰氟是溴甲烷土壤消毒很有前景的替代品。     

我国启动首家替代甲基溴（溴甲烷）环保项目

我国淘汰甲基溴国家行动计划项目近日正式启动，由秦皇岛市领先科技发展有限公司研发的《用于土壤消毒的甲基溴生物替代技术培训与推广》项目得到了联合国《蒙特利尔议定书》多边基金的批准和资助，从而使我国成为第一个开发此类生物替代甲基溴技术的国家。     

溴甲烷熏蒸辣椒的试验

对进口的少量传带辣椒实蝇Ｂａｃｔｒｏｃｅｒａ（Ｂａｃｔｒｏｃｅｒａ）ｌａｔｉｆｒｏｎｓ（Ｈｅｎｄｅｌ）的辣椒用溴甲烷（ＭｅｔｈｙｌＢｒｏｍｉｄｅ）在聚氯乙烯袋内熏蒸,在３２℃,３０ｇ／ｍ３,熏蒸２小时,ＣＴ值６０;２２℃,３６ｇ／ｍ３,２小时,ＣＴ值７２;１５℃,４０ｇ／ｍ３,２小时,ＣＴ值８０,均能有效熏杀辣椒实蝇幼虫     

溴甲烷在我国的应用现状和前景分析

溴甲烷在我国的应用现状和前景分析谌运清姜良郎苏长流（连云港动植物检疫局２２２０４２）（连云港海水化工一厂２２２０４２）自从ＬｅＧｒｏｕｐｉｌ１９３２年首次报道溴甲烷的杀虫特性以来，溴甲烷作为熏蒸剂已有６０多年的历史，因其作用范围广、杀虫迅速等特点已使...     

溴甲烷对红火蚁的熏蒸效果研究

以广东口岸进口原木和废纸上携带的红火蚁Solenopsis invicta Buren为杀灭对象,测定了溴甲烷对其的熏蒸效果。在空箱内分别按6.01、12.01、22.52、25.53、28.53、31.53、34.53及37.54g/m3的浓度投药;在实箱内分别按25.53、28.53及31.53g/m3的浓度投药,每个处理分别熏蒸2,4,6和8h,试验结果表明:在空箱内投药浓度为34.53、28.53和22.52g/m3时分别熏蒸4、6及8h,货柜箱内的红火蚁全部被杀灭。在实箱内投药浓度为31.53、28.53、及25.53g/m3时分别熏蒸4、6及8h,均能完全杀灭货柜箱内红火蚁。其它投药浓度和熏蒸时间的组合均不能达到检疫除害的要求。     

溴甲烷土壤熏蒸处理，植物促生菌对大田黄瓜病害的生物防治作用

有人发现，植物生长促生菌（PGPR）能诱导黄瓜产生诱发系统抗性。为了进一步研究植物生长促生菌在有或无溴甲烷土壤熏蒸情况下对黄瓜生长及其自然发生的病害的作用，我们于1996年－1997年进行了田间试验，试验设7个植物生长促生菌的种子处理，其中包括枯草芽孢杆菌（Bacillus punilus)INR7,萎蔫短小杆菌（Curtolxacteriun flaccunfaciens)ME1和枯草芽孢杆菌（Bacillus punilus)GBO33个菌株的单菌株处理及其4个混合菌株的处理。两年的数据表明，在无溴甲烷（MeBr)土壤熏蒸的情况下，所有7个植物生长促生菌处理与空白对照组相比都能显著促进黄瓜植株生长；而在有溴甲烷熏蒸的情况下，同样7个植物生长促生菌试验处理中，1996年有3个处理而1997年只有1个处理显著促进植株生长。1996年试验结果表明，7种植物生长促生菌处理中，有或无溴甲烷熏蒸处理黄瓜主茎生长长度的结果均相似。两年的田间试验表明，有或无溴甲烷的熏蒸；7种植物生长促生菌处理与空白对照相比都能显著减轻黄瓜叶病的严重度。1996年自然发生的叶病是黄瓜角斑病（Pseudomonas syringae pv.lachrymans)，1997年出现的是炭疽病菌（Colletotrichum orbiculare)和角斑病的复合侵染现象。两年中，无论是有还是无溴甲烷熏蒸的情况下，植物生长促生菌菌株的混合物处理比单个菌株处理表现出较高的抗病作用。结果表明，植物生长促生菌诱导蔬菜产生的诱发系统抗性作为蔬菜病虫害综合防治中的一个措施，不应该受到从现有蔬菜生产技术标准中逐步取消溴甲烷而产一的负面影响，植物生长促生菌的促生作用能补偿在无溴甲烷土壤熏蒸处理下造成的植株生长减少。     

溴甲烷的替代技术初探

本文综述了溴甲烷的历史和现状，从药剂和处理方法两个方面探讨了可替代溴甲烷的技术。     

Permeability of plastic films to methyl bromide: a comparative laboratory study

The permeability of plastic films to the fumigant methyl bromide (MB) was measured by two different methods, in order to facilitate the selection of films which are impermeable to the gas. Polyethylene-based films are highly permeable to MB, as evidenced by both methods. In contrast, multilayer coextruded films which have a layer of barrier material such as polyamide (PA) or ethylene-vinyl alcohol copolymer (EVOH) were significantly less permeable to MB, as reflected by the parameters permeability rate, time to 90% concentration (TC₉₀, by the diffusion method) and lag-time values (by the variable-volume method). A significant correlation was found between the permeability rate assessed by the diffusion method and that obtained with the variable-volume method. Permeability of all films increased with temperature as evidenced by all tested parameters. This increase was more pronounced with polyethylene films, the permeabilities of which increased five- to six-fold when the temperature was increased from 20°C to 60°C. The effect of temperature on barrier-film permeability was less significant. Permeability of films to MB was affected by additional factors such as additives, the length of the monomer side-chain, and the thickness and density of polyethylene films. © 1998 SCI     

完全不渗透膜对熏蒸剂大气散发的控制效果

为明确完全不透性膜(totally impermeable film,TIF)对熏蒸剂在田间应用时散发和残留的影响,采用静态散发箱技术测定了TIF与聚乙烯膜(polythene film,PE)对氯化苦、1,3-二氯丙烯(1,3-dichloropropene,1,3-D)和棉隆施用后所产生的异硫氰酸甲酯(methyl isothiocyanate,MITC)大气散发的控制效果,并应用气相色谱法检测了揭膜后3种熏蒸剂在土壤中的残留情况。结果表明,在20 g/m~2(棉隆为15 g/m~2)剂量下,氯化苦、1,3-D及MITC透过PE的累积散发率为施用量的6.42%、7.37%和22.27%,透过TIF的累积散发率为施用量的0、0.65%和2.05%,表明TIF极大地降低了熏蒸剂向大气的散发量,可有效控制熏蒸剂向大气扩散。揭膜后氯化苦及1,3-D在各处理土壤中的残留量均低于0.30 mg/kg,说明TIF没有增加土壤中氯化苦和1,3-D的残留量;但MITC(15 g/m~2)在TIF下10~20 cm土壤中的残留量在3.28~3.41 mg/kg之间,高于在PE下的残留量(0.46~0.47 mg/kg),表明TIF能提高MITC在土壤中的持效浓度。     

Effects of reduced‐rate methyl bromide applications under conventional and virtually impermeable plastic film in perennial crop field nurseries

BACKGROUND: Producers of perennial crop nursery stock in California use preplant soil fumigation to meet state phytosanitary requirements. Although methyl bromide (MB) has been phased out in many agricultural industries, it is still the preferred treatment in the perennial nursery industry and is used under Critical Use Exemptions and Quarantine/Preshipment provisions of the Montreal Protocol. The present research was conducted to evaluate reduced‐rate MB applications sealed with conventional and low‐permeability plastic films compared with the primary alternative material. RESULTS: Reduced rates (100–260 kg ha^?1) of MB applied in combination with chloropicrin (Pic) and sealed with a low‐permeability plastic film provided weed and nematode control similar to the industry standard rate of 392 kg ha^?1 MB:Pic (98:2) sealed with high‐density polyethylene (HDPE) film. However, the primary alternative chemical, 1,3‐dichloropropene (1,3‐D), tended to provide slightly lower pest control even on sites with relatively low plant parasitic nematode, soil‐borne pathogen and weed pest pressure. CONCLUSION: If California regulations change to allow the use of low‐permeability films in broadcast fumigant applications, the results of this research suggest that reduced rates of MB in perennial crop nurseries could serve as a bridge strategy until more technically, economically and environmentally acceptable alternatives are developed. Published 2010 by John Wiley & Sons, Ltd.     

Allium spp thiosulfinates as substitute fumigants for methyl bromide

Methyl bromide, the most widely used fumigant, is considered to be one of the major factors causing depletion of the ozone layer, and this is likely to lead to it being banned in the near future. Allium sulfur volatiles (thiosulfinates, R-S-SO-R′; R, R′=Me, Pr, y Allul), known to be nematicides, have been evaluated as insecticides against insect pests in stored products, in comparison with their degradation compounds (disulfides) which have already been tested. Methyl and allyl thiosulfinates, with 24-h LD₅₀ values of 0.02–0.25 mg litre⁻¹, were more active than disulfides against six test insects and were superior to methyl bromide; it is suggested that they could be used as alternatives to methyl bromide in stored product control. ©1999 Society of Chemical Industry     

Dose response of weeds to methyl iodide and methyl bromide

Labonuory bioassay and field experiments were conducted to characterize the dose response of weeds to methyl iodide and methyl bromide as soil fumigants. The patterns in potency of both fumigants and in sensitivity of diffcretit weed species to the fumigants were distinguished with the use of logistic dose-response models. Similar to its response to methyl hromide fumigation. Amaranthus retrofleus L. was the most sensitive to methyl iodide fumigation. Cyperus rotundtis L. was the least sensitive to methyl iodide fumigation, whereas Portuloca oleracea L. was the least sensitive to methyl hromide. Lolium multiflorum Lam. Abutilon theophrasti Medik. Chenopodium album L. P. ateracea . Brassica kaber (D.C.) L.C. Wheeler and Cyperus escuden-tus L. were similar in sensitivity to methyl iodide. Methyl iodide was as potent as methyl bromide for A. retroflexus but more potent than methyl bromide for L. multiflorum , A. theophrasti. C. album. P. oleracea. B. kaber, C. esculentus and C. rotundus. The dose response for weeds in the field was similar to that obtained in laboratory bioassays. Under fieid conditions. 280 kg ha^-1 methyl iodide killed all species tested except Solanum nigrum L Methyl iodide appears to be a suitable replacement for meihyl bromide because it can be used in situations simitar to methyl bromide fumigation, has superior efficacy against a broad spectrum of pests and has a low potential for degrading the earth's ozone lavers.     

Effect of soil physical factors on methyl iodide and methyl bromide

Production and importation of methyl bromide is scheduled to be banned by 2001. Methyl iodide was evaluated as a possible replacement soil fumigant. The effects of soil moisture, temperature, soil texture and fumigation time on the efficacy of methyl iodide for the control of two common weeds, Abutilon theophrasti and Lolium multiflorum, were characterized and compared with those of methyl bromide. The optimal soil moisture for methyl iodide to kill both weed species in sandy soils was 14% water content (w/w). Greater efficacy was obtained when the temperature during fumigation was above 20°C. Compared to methyl bromide, the efficacy of methyl iodide was more consistent in different soils. Time to 100% mortality of weeds was 24 h for methyl iodide fumigation and 36 h for methyl bromide when 200 μM of fumigant was used. On a molar basis methyl iodide was consistently more effective than methyl bromide across the range of environmental factors tested. In terms of application technology and spectrum of activity, methyl bromide can be directly replaced by methyl iodide. © 1998 SCI     

Toxicity of methyl bromide to soil-borne fungi

Nineteen fungal isolates, mostly plant pathogens cultured on agar, were subjected to fumigation with methyl bromide at known concentration x time product (CTP, concentration in mg/1 x time in h) in a fumigation chamber at controlled temperature. Survival of the fungi was determined by sub-culturing on fresh agar. An order of methyl bromide tolerance of the fungi was cetermined and it was shown that at low concentrations of the fumigant, prolonged exposure, to give a normally toxic CTP, did not kill important soil-borne pathogens. The implication of this in relation to field fumigations is discussed.     

Residual free methyl bromide in fumigated commodities

The extent to which methyl bromide was retained by fumigated material after treatment was followed in laboratory studies on a range of commodities exposed to the vapour at atmospheric pressure. Amounts of methyl bromide, recovered by solvent extraction and determined using gas-liquid chromatography, were related to the temperature, moisture content and manner of post-treatment storage. Immediately after exposure, the initial amount of free methyl bromide present was more dependent on the gas concentration used than on the time of exposure. Under the experimental conditions of exposure, the residual free methyl bromide in all commodities fumigated at 25°, except cocoa beans and groundnuts, fell to below 1 ppm within a few days when they were held at that temperature, whether spread in thin layers on trays or kept sealed in glass bottles. At lower temperatures, the rate of loss was slower, small amounts of methyl bromide being extracted from several commodities one month after treatment. The disappearance of fumigant from wheat and sultanas was more rapid from samples with higher moisture contents. A mathematical treatment of the data is presented, to assist in prediction of the behaviour of residual fumigant under storage conditions before processing. It is concluded that the risk of ingestion of harmful quantities of free methyl bromide by the consumer is small and that the occasions when relatively high residues might occur can be predicted.