农药助剂和实验室常用有机溶剂对大型溞的室内急性毒性研究

本文研究了13种农药常见助剂及6种实验室原药检测中常用的助剂对水生物大型溞的急性活动抑制毒性,试验结果表明GY-W04和K12对大型溞的毒性较大,48h的EC50分别4.03mg/L和4.19mg/L,甲醇、乙醇、丙酮、二甲基甲酰胺、二甲基亚砜、吐温80的毒性很小,GY-800和GY-900的毒性较小,其EC50分别为2 530.04 mg/L和2 976.27mg/L,从而为今后有关助溶剂的研究与管理工作提供基础数据。     

Tank-mix adjuvants and pesticide residues: some regulatory and quantitative aspects

Although it is well known that judicious use of adjuvants can increase the performance of foliage-applied sprays of many agrochemicals, little information is available in the public domain about their ultimate effects on pesticide residues in treated crops. In the present work, the influence of Agral (polyoxyethylene nonylphenols), Toil (methyl esters of rapeseed fatty acids) and Bond (styrene-butadiene copolymers) on surface and crop residues of diclofop-methyl/diclofop and propiconazole in wheat and field beans was investigated using a model system simulating field practice. Pesticides were applied as commercial formulations, diclofop-methyl 378 g litre(-1) EC (Hoegrass) and propiconazole 250 g litre(-1) EC (Tilt), at their maximum approved rates, 1135 g AI ha(-1) and 125 g AI ha(-1), respectively, both in the presence or absence of the maximum rate recommended for each candidate adjuvant. No detectable residues of diclofop-methyl or propiconazole were found in wheat 35 days after any of the four applications. However, residues of diclofop were present in this crop, and those from applications containing Agral (0.07 mg kg(-1) fresh weight (FW)) or Bond (0.08 mg kg(-1) FW) were significantly lower than those with no adjuvant (0.14 mg kg(-1) FW) or Toil (0.16 mg kg(-1) FW). Unlike wheat, residues of both diclofop and propiconazole were detected in field beans after harvest. Significantly higher residues of the former were recorded from the applications with Agral or Bond (ca 0.32 mg kg(-1) FW) than with those with no adjuvant or Toil (ca 0.15mg kg(-1) FW). All the propiconazole applications containing adjuvants showed a similar significant increase in residues (0.10-0.16 mg AI kg(-1) FW) over the no-adjuvant treatment (0.05 mg kg(-1) FW) in this crop. There appeared to be little agreement between the apparent amounts of uptake, as indicated by the rates of decline of surface residues up to 5 days after application, and final residues in either target species. On wheat, surface residues of diclofop-methyl decreased from initially ca 20 to as little as 0.02 mg kg(-1) FW using adjuvants; the corresponding values for propiconazole were ca 2 to ca 0.03 mg kg(-1) FW. Recoveries of diclofop-methyl from the surfaces of field beans were much higher than those from wheat, declining from ca 30 to only ca 6 mg kg(-1) FW during the course of 5 days; the corresponding residues for propiconazole were ca 2 mg to 0.15 mg kg(-1) FW. These findings are discussed in relation to uptake results obtained with radiolabelled pesticides and adjuvants in the laboratory, and to the mandatory requirements for pesticide residue data for the authorised use of adjuvants in the UK.     

Reinvestigating adjuvants for the wild oat herbicide,flamprop-M-isopropyl. II: Field performance

A field trials programme was conducted in which the performance of a new emulsifiable concentrate formulation (ECI) of flamprop-M-isopropyl containing the adjuvant, ‘Dobanol’ 25-7, in a ratio of 2:1 (by weight) with the AI, was compared with the current commercial formulation of ‘Commando’, in combination with its recommended adjuvant, ‘Swirl’, for the control of wild oat (Avena fatua L.) in wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.). A further treatment, in which the ‘Dobanol’ 25-7: AI ratio was increased to 4:1 by the spray tank addition of the former, was also included. The mean results from six trials (five wheat, one barley) showed that the addition of ‘Swirl’ to ‘Commando’ was beneficial, increasing wild oat floret control from a mean value of 80% to 92% at current recommended rates (flamprop-M-isopropyl, 600 g ha^?1; ‘Swirl’, 2.5 litre ha^?1). However, combinations of flamprop-M-isopropyl and ‘Dobanol’ 25-7 gave superior levels of control even at lower AI application rates. For example, a mean level of 96% control of Avena spp. was obtained at 300 g AI ha^?1 with 1200 g ha^?1 ‘Dobanol’ 25–7; with even better control at higher rates of application of both components. This improvement in performance was accompanied by a higher risk of crop phytotoxicity than observed with the ‘Commando’/‘Swirl’ mixtures. Symptoms initially were scorch and subsequently growth depression, particularly of tillers. None of the mean values in the six ‘efficacy’ trials reached commercially unacceptable levels, but in a further six ‘crop effects’ trials (three wheat, three barley), in which double rates were applied, the levels of phytotoxicity did become unacceptable and subsequently reduced grain yields. In contrast, two barley ‘crop effects’ trials gave yields higher than the control plots, possibly through the effects of reducing stem length and lodging thereby enabling more efficient harvesting. Nevertheless, there were rates of application of flamprop-M-isopropyl in the range 300–400 g ha^?1 with ratios of ‘Dobanol’ 25-7 in the range 2:1 to 4:1 that would achieve high levels of control of Avena spp. without undue risk of crop phytotoxicity and further trials are planned to support this new adjuvant system.     

两种喷雾助剂对氟磺胺草醚在反枝苋上的 吸收和药效的影响

采用14C-氟磺胺草醚同位素标记法研究了喷雾助剂JFC 和ABS(十二烷基苯磺酸钠)对14C-氟磺胺草醚在反枝苋上的吸收和药效的影响。结果表明,在药液中添加2 g/L的JFC ,反枝苋对14C-氟磺胺草醚的吸收面积可增加1.4倍,吸收量增加3.2倍,药效提高28.5%;添加2 g/L的ABS ,反枝苋对14C-氟磺胺草醚的吸收面积增加1.3倍,吸收量增加1.0倍,药效提高19.2%。JFC不但具有促进药液在反枝苋叶面扩展的能力,还具有促进药剂渗透的能力,当添加2 g/L的JFC 时,反枝苋单位面积吸收强度增加75.7%;ABS基本上不能增加反枝苋单位面积的吸收强度,只具有促进药液扩展的能力。     

3种不同类型佐剂的猪圆环病毒2型亚单位灭活疫苗免疫效果的比较研究

为制备猪圆环病毒2型商品化亚单位疫苗选择良好的佐剂,对由水性佐剂GEL 01、白油佐剂以及氢氧化铝胶佐剂分别制备的3种猪圆环病毒2型亚单位疫苗的免疫效果进行比较研究。本实验选取3~4周龄猪圆环病毒2型抗体阴性猪30头,根据试验疫苗接种情况分为6组,分别为:3种不同佐剂制备的亚单位疫苗(A组、B组和C组)、商品化疫苗(D组)以及空白对照组和攻毒对照组,然后进行临床观察、抗体水平监测和免疫效力评价,观察各组仔猪的不良反应情况、抗体水平以及攻毒保护情况。结果显示:3种不同类型佐剂制备的猪圆环病毒2型亚单位疫苗接种猪后均无任何不良反应、能刺激机体产生良好的ELISA抗体水平和免疫效果,但水性佐剂GEL 01制备的疫苗与另外2种佐剂制备的疫苗相比,综合抗体水平、免疫效果等因素,水性佐剂GEL 01制备的疫苗在临床使用上更具优势,为商品化亚单位疫苗佐剂的选择提供了重要的数据支持。     

CpG ODN重组质粒对猪外周血淋巴细胞免疫刺激作用的研究

为获得对猪具有免疫刺激活性的含CpG序列的重组质粒,设计合成了11条CpG序列,应用MTS比色法测定合成CpG ODNs刺激猪PBMC增殖的能力,结果有10条CpG ODN对猪PBMC具有刺激活性(SI>2);以对猪PBMC具有较高刺激活性的CpG06和CpG08为核心,分别合成含6次重复序列的重组质粒pCpG06和pCpG08,并检测其对猪PBMC的刺激活性,结果重组质粒pCpG06和pCpG08对猪PBMC的刺激指数分别可达4.97和5.32,并可刺激猪PBMC产生较高水平的IL-4。研究获得的重组质粒pCpG06和pCpG08对猪PBMC具有较好的刺激活性,可为猪用CpG佐剂的研究提供参考。     

重组白介素-2增强口蹄疫病毒多表位疫苗免疫效果研究

通过研究重组白细胞介素-2（IL-2）对口蹄疫病毒（FMDV）多表位疫苗免疫效果的增强作用,为IL-2作为 FMDV 表位疫苗佐剂应用提供实验依据。6周龄雌性 Balb／c 小鼠,分为4组,第1组联合免疫表达猪 IL-2的重组腺病毒（rAd5poIL-2）和串联表达 FMDV 多表位基因的重组腺病毒（rAd5EGS）,第2、3和4组分别注射 rAd5EGS、灭活疫苗和 PBS,间隔2周免疫1次,共免疫3次。首免后每周采血分离小鼠血清,通过 ELISA 检测血清中特异性 IgG;首免后6周检测血清中抗体亚型 IgG1、IgG2a 及细胞因子 IL-4和 IFN-γ的表达水平,同时分离脾细胞,MTT 法检测淋巴细胞增殖指数。结果显示,联合免疫 rAd5poIL-2和rAd5EGS 既能增强 rAd5EGS 诱导小鼠特异性 IgG、IgG1和 IgG2a 的分泌,又能增强其诱导淋巴细胞增殖能力,且免疫效果强于灭活疫苗;细胞因子检测结果显示,联合免疫 rAd5poIL-2后能增强 rAd5EGS 诱导小鼠 IL-4和 IFN-γ的分泌,且其诱导 IL-4和 IFN-γ分泌能力也强于灭活疫苗。说明重组 IL-2能有效增强FMDV 多表位疫苗诱导抗体分泌能力和细胞免疫应答,rAd5poIL-2有望作为 FMDV 表位疫苗的候选佐剂。     

氟虫腈药液在水稻叶片上的沉积特性研究

以氟虫腈悬浮剂为研究对象探讨了药液在水稻叶片上的沉积特性。随着雾流方向角增大,药液在稻叶上的沉积量显著增加,雾流方向角为30°、45°与60°处理时药液的沉积量分别比0°处理者提高了16.6％、39.3％与70.1％。随着雾滴体积中径(VMD)增大,氟虫腈药液在稻叶上的沉积量降低,VMD为157.3、193.2、215.4、233.7 μm 处理的药液沉积量分别比VMD 149.5 μm处理降低了16.2％、39.1％、49.5％与66.4％。施药液量少于339 L/hm2时,药液在稻叶上的沉积效率较高,为25.6％ ~28.1％,药液在稻叶上的最大稳定持留量约为 1.42 μL/cm2。较少施药液量和较小雾滴的处理,加入有机硅(150 g/hm2)后药液的沉积量可提高80％ ~150％,但施药液量增加至694.5 L/hm2 (VMD 233.7 μm)时,药液沉积量未增加。根据本实验结果,施药时采用较小雾滴和较少施药液量,雾流方向角45°~60°,并加入有机硅作为喷雾助剂,药液在稻叶上的沉积效率较高。     

我国农药助剂工业发展与管理概况

本文介绍了农药助剂的使用历史、发展现状及未来趋势,阐述了我国农药助剂产业存在的问题及国际助剂管理情况和我国加强对农药助剂管理的必要性。     

助剂对精喹禾灵防治棉田杂草的减量增效作用

【目的】研究添加助剂对精喹禾灵EC防除棉田禾本科杂草的增效作用,为除草剂减量施用和科学除草提供数据基础。【方法】通过温室盆栽和田间小区试验,在除草剂常规用量、减量20%和减量40%基础上添加助剂,比较精喹禾灵EC对马唐、牛筋草等禾本科杂草的防除效果。【结果】盆栽试验中,在推荐的常量用药水平下添加助剂Foxy SG和Fieldor Max EC,精喹禾灵EC对马唐和牛筋草2种禾本科杂草防效提高1.75%~5.78%,精喹禾灵EC减量20%和40%,2种助剂对防效的增效幅度分别为7.95%~10.54%和21.62%~41.63%,Fieldor Max EC的增效作用显著优于Foxy SG,精喹禾灵EC减量40%后添加Fieldor Max EC对禾本科杂草的防效与常量用药防效无显著差异;田间试验中,2种助剂对精喹禾灵EC的减量增效作用与盆栽试验结果相符,常量用药水平下添加Foxy SG和Fieldor Max EC,精喹禾灵EC对禾本科杂草株防效和鲜重防效提高0.83%~4.19%,精喹禾灵EC减量20%和40%,2种助剂对防效的增效幅度分别为1.08%~8.68%和12.06%~37.74%,Fieldor Max EC的增效作用显著优于Foxy SG,精喹禾灵EC减量40%后添加Fieldor Max EC对禾本科杂草的株防效与常量用药株防效无显著差异。【结论】Foxy SG和Fieldor Max EC 2种助剂,对棉田常用的选择性除草剂精喹禾灵EC除草活性有明显提高,减少除草剂使用量后加入助剂可解决防效降低问题,除草剂使用过程中加入高效助剂是实现除草剂减量增效的有效途径。