摘要:
采用枯叶指数、枯柄指数、新根抑制、鲜重防效等指标,评价草甘膦异丙胺盐对水葫芦的防除作用,并测定其在水中的残留。盆栽毒力测定结果表明,草甘膦异丙胺盐对水葫芦新根的抑制作用最强,LC50为185.54μg·L-1,对叶、叶柄、鲜重的毒力较弱,LC50分别为385.89 g·L-1、475.82 g·L-1、790.86 g·L-1。田间水域试验结果表明,草甘膦异丙胺盐对水葫芦的新根有很好的抑制效果,药后40 d,1.91 g·L-1的抑制效果达100%。草甘膦异丙胺盐防除叶片的速效性较好,施药后20 d,1.91 g·L-1对叶片的防除效果达96.69%,优于40 d后85.42%的防效。草甘膦异丙胺盐对叶柄和鲜重的防除效果较差,1.91 mg·L-1草甘膦异丙胺盐处理40 d后,对叶柄和鲜根的防效分别为52.34%、63.18%。在室内静止水体与流水中分别施用1.37 mg·L-1、1.91 mg·L-1和2.73 mg·L-1草甘膦异丙胺盐防除不同覆盖率(0%、60%、90%)的水葫芦后,水体中残留量均未超过0.7mg·L-1最高污染物水平(美国一级饮用水标准)。
关键词:
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水葫芦 /
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草甘膦异丙胺盐 /
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防除 /
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残留
Abstract:
The control of Eichhornia crassipes Solms with glyphosate isopropylamine was evaluated by using leaf-withering index,petiole-withering index,inhibition of new roots,and fresh-weight.Residues of glyphosate isopropylamine in water was also determined.Glyphosate isopropylamine showed a high inhibition effect on new root with an LC50 f 185.54 μg·L-1.The herbicide showed a relatively low toxicity to lamina,petiole and fresh-weight of E.crassipes in the laboratory test.The LC50 on lamina,petiole,and fresh-weight reached 385.89 μg·L-1,475.82 μg·L-1,and 790.86 μg·L-1,respectively.The control of E.crassipes with glyphosate isopropylamine was also conducted in the field.Glyphosate isopropylamine at the dose of 1.91 mg·L-1 inhibited the generation of all new roots.Glyphosate isopropylamine(1.91 mg·L-1) showed 96.69% control efficiency on lamina after treatment for 20 days,while only 85.42% control efficiency was found after 40 days.The control efficiencies of the herbicide on petiole and fresh-weight were were relatively low,i.e.,52.34% and 63.18%,respectively,at the dose of 1.91 mg·L-1.Glyphosate isopropylamine applications in still and running water bodies that were 0%,60%,and 90% covered with E.crassipes were 1.37 mg·L-1,1.91 mg·L-1,and 2.73 mg·L-1,respectively.The glyphosate isopropylamine residues after the applications were all lower than 0.7 mg·L-1,the maximum limit for drinking-water set by EPA in the U.S.
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