除草剂安全剂的作用机制研究进展

本文对国内外关于除草剂安全剂的作用机制研究情况进行了介绍,并对几种较为普遍认同的作用机制重点给予解释。     

三唑酰草胺在不同类型土壤中的降解特性

为科学评价除草剂三唑酰草胺在土壤环境中的生态风险,采用室内模拟方法,研究了三唑酰草胺在吉林黑土、江西红土和安徽水稻土中的降解特性。结果表明:三唑酰草胺在土壤中的降解符合一级动力学方程。好氧条件下三唑酰草胺在3种土壤中的降解半衰期分别为86.5、106和91.4 d;厌氧条件下半衰期分别为106、130和127 d;水稻田厌氧条件下半衰期分别为162、219和188 d。研究表明,三唑酰草胺在水稻田厌氧条件下的降解速率明显慢于其他2种试验条件下。     

Multifunctionalised benzoxazinones in the systems Oryza sativa–Echinochloa crus‐galli and Triticum aestivum–Avena fatua as natural‐product‐based herbicide leads

BACKGROUND: Fifteen novel derivatives of D‐DIBOA, including aromatic ring modifications and the addition of side chains in positions C‐2 and N‐4, had previously been synthesised and their phytotoxicity on standard target species (STS) evaluated. This strategy combined steric, electronic, solubility and lipophilicity requirements to achieve the maximum phytotoxic activity. An evaluation of the bioactivity of these compounds on the systems Oryza sativa–Echinochloa crus‐galli and Triticum aestivum–Avena fatua is reported here. RESULTS: All compounds showed inhibition profiles on the two species Echinochloa crus‐galli (L.) Beauv. and Avena fatua L. The most marked effects were caused by 6F‐4Pr‐D‐DIBOA, 6F‐4Val‐D‐DIBOA, 6Cl‐4Pr‐D‐DIBOA and 6Cl‐4Val‐D‐DIBOA. The IC₅₀ values for the systems Echinochloa crus‐galli–Oryza sativa and Avena fatua–Triticum aestivum for all compounds were compared. The compound that showed the greatest selectivity for the system Echinochloa crus‐galli–Oryza sativa was 8Cl‐4Pr‐D‐DIBOA, which was 15 times more selective than the commercial herbicide propanil (Cotanil‐35). With regard to the system Avena fatua–Triticum aestivum, the compounds that showed the highest selectivities were 8Cl‐4Val‐D‐DIBOA and 6F‐4Pr‐D‐DIBOA. The results obtained for 6F‐4Pr‐D‐DIBOA are of great interest because of the high phytotoxicity to Avena fatua (IC₅₀ = 6 µM , r² = 0.9616). CONCLUSION: The in vitro phytotoxicity profiles and selectivities shown by the compounds described here make them candidates for higher‐level studies. 8Cl‐4Pr‐D‐DIBOA for the system Echinochloa crus‐galli‐Oryza sativa and 6F‐4Pr‐D‐DIBOA for Avena fatua‐Triticum aestivum were the most interesting compounds. Copyright © 2010 Society of Chemical Industry     

7种除草剂防除冬小麦田杂草的效果比较

对7种除草剂防除冬小麦田杂草的效果进行了比较研究。结果表明,7种除草剂均对小麦田杂草有较好的防除效果。综合考虑防效、增产效果、经济成本等因素．田间以禾本科杂草为主可施用精嗯唑禾草灵,以阔叶杂草为主可施用苯磺隆、氯氟吡氧乙酸,阔叶杂草与禾本科杂草混合发生．可用精嗯唑禾草灵与其它防除阔叶杂草的除草剂混合施用或施用氯氟吡氧乙酸·异丙隆。     

乙酰乳酸合成酶及其抑制剂研究新进展

乙酰乳酸合成酶（AHAS）是支链氨基酸生物合成途径中的一个关键酶,是绿色除草剂的重要作用靶标。由于此生物合成过程只存在于植物和微生物体内,因此该类抑制剂对哺乳动物具有生物安全性。近年来,随着AHAS三维结构的阐明,人们不仅深入了解了已有抑制剂的作用机制,并且依此设计开发了一些新型的抑制剂, 拓展了其在抑菌活性方面的生物学功能。文章对近年来AHAS及其抑制剂的最新研究进展进行了综述,重点就AHAS的酶学特征、结构特征及结合方式,以AHAS为靶标的新颖除草活性化合物的设计开发以及AHAS抑制剂的抗菌生物活性研究进展等问题详细进行了总结,以期为设计开发靶向AHAS的新型除草剂或抗菌药物提供参考。     

不同小麦品种对苯磺隆除草剂的耐药性研究

通过敏感性测定,明确了不同小麦品种对麦田磺酰脲类除草剂苯磺隆的耐药性。结果表明:河东TX耐药性较强;晋麦67、晋农66、晋麦47、长5456、农大3608耐药性居中;长006219、乐39耐药性较弱。长006219对苯磺隆药剂的敏感性最强,用药不当,易产生药害。对品种耐药性以及药剂抑制力的进行了综合分析。     

植物源农药的研究

植物源农药就其低毒、低残留、与环境和谐、对非靶标生物相对安全等优点,符合现代环保和人们健康的要求而越来越引起人们的高度重视。本文综述植物源农药的资源、植物源农药杀虫剂、杀菌剂和除草剂等的研究进展。     

浙南山区龙泉市化学除草剂应用现状与对策

对龙泉市化学除草剂的使用情况进行调查,分析存在的主要问题,并就科学应用化学除草剂提出5方面对策.     

Effect of herbicides and annual weeds on the yield and seed quality of lathyrus (Lathyrus sativus L.)

Field research conducted over six location years has indicated that lathyrus (Lathyrus sativus L.) is a poor competitor with annual weed species. Failure to control annual weeds reduced lathyrus seed yields by 54–95%, depending on the weed species present and their density. Weed competition also reduced thousand-seed weight. Preplant soil-incorporated applications of trifluralin and postemergence applications of sethoxydim controlled wild oat (Avena fatua L.) and green foxtail (Setaria viridis (L.) Beav.). Trifluralin failed to control wild mustard (Sinapis arvensis L.), an important broad-leaved weed in western Canada, but this weed was controlled by both preplant soil-incorporated and postemergence applications of metribuzin. Lathyrus exhibited excellent tolerance to these herbicides, which are currently registered for use on high-acreage crops in Canada.     

The influence of herbicides on the soil microflora in a plum orchard

The effects of 2.5, 5.0 and 7.5 kg ha^?1 of simazine, atrazine, diuron and bromacil, and 2.0, 3.0 and 4.0 kg ha^?1 of terbacil on the soil microflora was studied in the soil of a plum orchard. A stimulatory effect on the bacterial population and an inhibitory effect on actinomycetes was observed under all the herbicidal treatments up to 60 days from application. Thereafter, the effect levelled off. An inhibitory effect on fungi was noticed with diuron, bromacil and terbacil, but a promotive effect with simazine and atrazine. In general, the herbicide effect lasted up to 60 days and the microbial status of the soil was not significantly disturbed at low and medium concentrations.