The degradation of imazapyr in non-sterile and sterile soils from four sampling sites in Zhejiang, China was studied. The results showed that the half-lives of imazapyr in non-sterile soils were in the range of 30 to ...The degradation of imazapyr in non-sterile and sterile soils from four sampling sites in Zhejiang, China was studied. The results showed that the half-lives of imazapyr in non-sterile soils were in the range of 30 to 45 d, while 81 to 133 d in sterile(by autoclaving) soils. It means the rate constants of imazapyr under non-sterile conditions were 2 3—4 4 times faster than that under sterile(by autoclaving) conditions, evidently indicating that the indigenous microorganisms in soil play an important role in the degradation of imazapyr. The different sterilization methods could result in different degradation rates of imazapyr. The heat of sterilization of soil largely decreased the degradation. However, the sterile treatment of soil by sodium azide had a different effect from that by autoclaving. Further more, the mechanism was also discussed. Biodegradation in four non-sterile soils accounted for 62% to 78% of imazapyr degradation. In contrast, less than 39% of imazapyr degradation was associated with chemical mechanisms. Therefore, the degradation mechanism was predominantly involved in biology including organisms and microorganisms in soil. Two imazapyr-degrading bacterial strains were isolated in enrichment culture technique and they were identified as Pseudomonas fluorescenes biotypeⅡ(ZJX-5) and Bacillus cereus(ZJX-9), respectively. When added at a concentration of 50 μg/g in mineral salts medium(MSM), ZJX-5 and ZJX-9 could degrade 81% and 87% imazapyr after 48 h of incubation. For the treatment of incorporation of ZJX-5 or ZJX-9 into soil, the degradation rate enhanced 3—4 fold faster than that for control samples, which showed an important value in quick decontamination of imazapyr in soil.展开更多
[目的]明确25%咪唑烟酸水剂对非耕地杂草及恶性杂草狗牙根的防治效果。[方法]通过茎叶喷雾试验,比较咪唑烟酸、百草枯、草甘膦和草铵膦对非耕地杂草及狗牙根的防治效果。[结果]25%咪唑烟酸水剂1125、1500 ga.i./hm^2处理药后40 d对非耕...[目的]明确25%咪唑烟酸水剂对非耕地杂草及恶性杂草狗牙根的防治效果。[方法]通过茎叶喷雾试验,比较咪唑烟酸、百草枯、草甘膦和草铵膦对非耕地杂草及狗牙根的防治效果。[结果]25%咪唑烟酸水剂1125、1500 ga.i./hm^2处理药后40 d对非耕地杂草的株防效分别为98.45%、99.22%,显著高于41%草甘膦1500 g a.i./hm^2株防效(94.22%)、18%草铵膦可溶液剂900 g a.i./hm^2株防效(93.75%)和20%百草枯可溶胶剂750 g a.i./hm^2株防效(74.59%);鲜重防效呈现出与株防效一致的结果;25%咪唑烟酸水剂750、1125、1500 g a.i./hm^2药后60 d对狗牙根的株防效和鲜重防效均显著高于其他处理药剂,且不易返青。[结论]咪唑烟酸可以替代百草枯、草甘膦等,防除非耕地杂草和狗牙根,持效期更长。展开更多
文摘The degradation of imazapyr in non-sterile and sterile soils from four sampling sites in Zhejiang, China was studied. The results showed that the half-lives of imazapyr in non-sterile soils were in the range of 30 to 45 d, while 81 to 133 d in sterile(by autoclaving) soils. It means the rate constants of imazapyr under non-sterile conditions were 2 3—4 4 times faster than that under sterile(by autoclaving) conditions, evidently indicating that the indigenous microorganisms in soil play an important role in the degradation of imazapyr. The different sterilization methods could result in different degradation rates of imazapyr. The heat of sterilization of soil largely decreased the degradation. However, the sterile treatment of soil by sodium azide had a different effect from that by autoclaving. Further more, the mechanism was also discussed. Biodegradation in four non-sterile soils accounted for 62% to 78% of imazapyr degradation. In contrast, less than 39% of imazapyr degradation was associated with chemical mechanisms. Therefore, the degradation mechanism was predominantly involved in biology including organisms and microorganisms in soil. Two imazapyr-degrading bacterial strains were isolated in enrichment culture technique and they were identified as Pseudomonas fluorescenes biotypeⅡ(ZJX-5) and Bacillus cereus(ZJX-9), respectively. When added at a concentration of 50 μg/g in mineral salts medium(MSM), ZJX-5 and ZJX-9 could degrade 81% and 87% imazapyr after 48 h of incubation. For the treatment of incorporation of ZJX-5 or ZJX-9 into soil, the degradation rate enhanced 3—4 fold faster than that for control samples, which showed an important value in quick decontamination of imazapyr in soil.
文摘[目的]明确25%咪唑烟酸水剂对非耕地杂草及恶性杂草狗牙根的防治效果。[方法]通过茎叶喷雾试验,比较咪唑烟酸、百草枯、草甘膦和草铵膦对非耕地杂草及狗牙根的防治效果。[结果]25%咪唑烟酸水剂1125、1500 ga.i./hm^2处理药后40 d对非耕地杂草的株防效分别为98.45%、99.22%,显著高于41%草甘膦1500 g a.i./hm^2株防效(94.22%)、18%草铵膦可溶液剂900 g a.i./hm^2株防效(93.75%)和20%百草枯可溶胶剂750 g a.i./hm^2株防效(74.59%);鲜重防效呈现出与株防效一致的结果;25%咪唑烟酸水剂750、1125、1500 g a.i./hm^2药后60 d对狗牙根的株防效和鲜重防效均显著高于其他处理药剂,且不易返青。[结论]咪唑烟酸可以替代百草枯、草甘膦等,防除非耕地杂草和狗牙根,持效期更长。
