扑·乙乳油防除大豆田杂草田间药效试验

采用田间小区试验方法,进行了质量分数为40%扑·乙乳油播后苗前土壤封闭处理防除大豆田杂草田间药效试验。结果表明:质量分数为40%扑·乙乳油对大豆田杂草有较好的防除效果,对单、双子叶杂草均有较高防效,45d杂草总防效为81 21%～88 34%,鲜重抑制效果为80 29%～88 21%。随使用剂量增加,药效逐渐提高,以400g 667m2防效最好,而且对大豆出苗及生长发育无不良影响,增产幅度为10 85%～14 55%。     

Dissipation of acetochlor and its distribution in surface and sub-surface soil fractions during laboratory incubations

Pesticides in soil are subject to a number of processes that result in transformation and biodegradation, sorption to and desorption from soil components, and diffusion and leaching. Pesticides leaching through a soil profile will be exposed to changing environmental conditions as different horizons with distinct physical, chemical and biological properties are encountered. The many ways in which soil properties influence pesticide retention and degradation need to be addressed to allow accurate predictions of environmental fate and the potential for groundwater pollution. Degradation and sorption processes were investigated in a long-term (100 days) study of the chloroacetanilide herbicide, acetochlor. Soil cores were collected from a clay soil profile and samples taken from 0-30 cm (surface), 1.0-1.3 m (mid) and 2.7-3.0 m (deep) and treated with acetochlor (2.5, 1.25, 0.67 microg acetochlor g(-1) dry wt soil, respectively). In sterile and non-sterile conditions, acetochlor concentration in the aqueous phase declined rapidly from the surface and subsoil layers, predominantly through nonextractable residue (NER) formation on soil surfaces, but also through biodegradation and biotic transformation. Abiotic transformation was also evident in the sterile soils. Several metabolites were produced, including acetochlor-ethane sulphonic acid and acetochlor-oxanilic acid. Transformation was principally microbial in origin, as shown by the differences between non-sterile and sterile soils. NER formation increased rapidly over the first 21 days in all soils and was mainly associated with the macroaggregate (>2000 microm diameter) size fractions. It is likely that acetochlor is incorporated into the macroaggregates through oxidative coupling, as humification of particulate organic matter progresses. The dissipation (ie total loss of acetochlor) half-life values were 9.3 (surface), 12.3 (mid) and 12.6 days (deep) in the non-sterile soils, compared with 20.9 [surface], 23.5 [mid], and 24 days [deep] in the sterile soils, demonstrating the importance of microbially driven processes in the rapid dissipation of acetochlor in soil.     

乙草胺在土壤环境中的降解及其影响因子的研究

采用实验室模拟方法研究了乙草胺在不同土壤中的降解动态。结果表明,在未灭菌的土壤中,乙草胺3种添加浓度(1.25、2.5和5.0mg·kg-1)处理的半衰期为2.8～5.1d,远远小于在灭菌土壤中3种添加浓度处理的半衰期(20.0～25.1d);乙草胺在偏碱的华北褐土中降解较快,2.5mg·kg-1处理的半衰期为4.2d,而在偏酸的东北黑土和湖南红土中降解较慢,半衰期为6.5～10.7d;土壤相对含水量由13%增至27%,乙草胺降解半衰期由7.3d缩短至3.0d;随着环境温度增高(20℃上升至30℃),乙草胺降解速度加快(半衰期由5.7d缩短至3.3d);乙草胺在黑暗条件下降解半衰期为3.8d,而在光照条件下的半衰期为5.2～6.5d。可见,5种试验因子对土壤中乙草胺的降解均有不同程度的影响。其中土壤微生物是影响乙草胺降解的主要因素,有利于土壤中微生物生长的环境因素,如偏碱的土壤、较高的环境温度和土壤湿度等,对土壤中乙草胺的降解有促进作用。     

莠·乙·烟47%悬浮剂防除夏玉米田杂草药效与安全性评价

结果表明,在夏玉米出苗后3～5叶期、杂草2～5叶期,大多数杂草出齐时施用莠·乙·烟47%悬浮剂150～200g/667m2(1057.7～1410g.a.i/hm2),对夏玉米田阔叶杂草和禾本科杂草均有较好的防除效果,并且有较长的持效期,对夏玉米生长安全。     

两种安全剂对小麦上乙草胺的解毒作用

以小麦的芽长和根长为测试指标,测定安全剂二氯丙烯胺和苯叉酰胺对乙草胺的解毒作用.结果表明,二者对乙草胺解毒作用明显,二氯丙烯胺浓度为10.0 μg·mL-1时对5.0 μg·mL-1乙草胺的解毒效果最好,对小麦芽解毒作用达到18.75%;苯叉酰胺浓度为20.0μg·mL-1时对0.5μg·mL-1乙草胺的解毒效果最好,对小麦芽解毒作用达到13.07%.但这两种安全剂不能完全解除乙草胺对小麦幼芽与幼根的毒害作用.     

除草剂解毒剂对玉米幼芽抗御乙草胺药害能力的影响研究

以垦玉6号玉米为指示材料,以乙草胺为试验除草剂,采用水培法研究了用除草剂解毒剂进行浸种处理后使玉米免受乙草胺药害的情况。结果表明:用不同浓度的解毒剂浸种处理后,能够在不同程度上减轻乙草胺对玉米幼苗的药害;当解毒剂浸种浓度为8mg·kg-1时保护效果达到最好,在乙草胺浓度为20mg·kg-1时,对玉米根长的保护率达20.4%,根鲜重的保护率达23.9%,对芽长的保护率达40.2%,芽鲜重的保护率达36.6%。     

除草剂乙草胺胁迫下油菜品种的耐药生理研究

研究甘蓝型油菜在乙草胺胁迫下的耐药生理对非转基因耐乙草胺的油菜新种质选育有重要意义?本研究以纸床法测定乙草胺耐药品种‘Norin 41’和敏感品种‘Dong Hae 1’生长7 d的幼苗进行生物性状?还原型谷胱甘肽代谢?抗氧化分析以及品种表型性状之间的相关性分析和主成分分析?结果表明, 耐药品种生长?根抗倒伏性?乙草胺解毒能力和抗氧化能力均强于敏感品种, 耐药品种的氧化损伤低于敏感品种?直立苗率?根-茎比?鲜重?超氧化物歧化酶活性?谷胱甘肽S-转移酶活性和丙二醛含量是反映品种耐药性的主要因素?这些研究结果为耐乙草胺种质选育提供了有益参考?     

益微微生物菌剂对乙草胺油菜药害的缓解效果及作用机制初步研究

为了探索益微微生物菌剂拌种缓解乙草胺油菜药害的效果及其作用机制,采用盆栽法测定了益微拌种对乙草胺油菜药害的缓解效果,采用分光光度法分别测定益微拌种对油菜叶片中还原型谷胱甘肽(GSH)、氧化型谷胱甘肽(GSSG)含量和谷胱甘肽转移酶(GST)活性的影响,并采用GCMS法检测油菜植株中乙草胺的残留量。结果表明:乙草胺的施用量为840~1 680 g/hm~2时,对油菜生长均有一定的抑制作用;用益微拌种处理后,均能显著缓解乙草胺对油菜的药害,当乙草胺用量为1 680 g/hm~2、拌种量为25 g益微拌1 kg油菜种子时,油菜的株高、鲜质量恢复率分别为79.31%和178.57%。与单用乙草胺处理相比,先用益微拌种后喷施乙草胺,油菜植株中GSH含量增加,GST活性提高,同时乙草胺残留量极显著降低。说明益微微生物菌剂能提高植株中相关抗逆酶的活性,促进乙草胺的降解,从而显著缓解乙草胺对油菜的药害。     

30%甲基磺草酮·乙草胺悬浮剂防治玉米田杂草试验

利用30%甲基磺草酮.乙草胺悬浮剂在玉米田进行除草试验,从除草效果、安全性和经济成本等综合分析得知,30%甲基磺草酮.乙草胺悬浮剂450 g a.i./hm2处理对阔叶杂草的目测防效和鲜质量防效均在93%以上,对稗草、狗尾草的防效在87%以上,总体防效大于90%,对玉米安全,可根据当地实际情况用于生产。     

气相色谱-氮磷检测法同时测定玉米中莠去津、乙草胺和丁草胺的残留量

建立气相色谱-氮磷检测法测定玉米中除草剂莠去津、乙草胺和丁草胺残留量的分析方法。玉米籽粒用乙腈提取,过中性氧化铝柱净化处理,用GC-FTD检测。在0.01、0.05和0.5 mg/kg 3个添加水平下,莠去津、乙草胺和丁草胺的平均添加回收率分别为84%~105%、81%~100%、87%~103%,相对标准偏差分别为1.0%~3.5%、1.1%~5.2%、3.7%~4.4%,莠去津、乙草胺和丁草胺在0.01~2.0 mg/L范围内呈良好的线性关系,最低检测浓度分别为0.005、0.01、0.01 mg/kg。该方法简单、灵敏、可靠,可应用于玉米中莠去津、乙草胺和丁草胺残留量的测定。