森草净杀灭薇甘菊(Mikania micrantha)及其安全性

Chemical herbicide salfometuron-Ethyl to controll Mikania micrantha and its residue in the soil

在深圳市内伶仃岛薇甘菊危害的不同群落生境中,设立9块样地81个小样方,用森草净(即70%嘧碘降水溶性粉剂)杀灭样地中的薇甘菊施量为0.0001～0.02g.m-2,结果表明:各浓度的森草净杀灭效果均较好,杀灭率随着用药量的增加而提高;在坡地和溪谷生境中,森草净用药量分别为0.05～0.1g.m-2、>0.2g.m-2能较彻底地杀灭薇甘菊。应用HPLC法检测样地土壤中嘧磺隆残留量,溪谷土壤中嘧磺隆半衰期C=C0.e-0.083T,T1/2=8.4,施药后37d消解95.9%,坡地高浓度级半衰期C=C0.e-0.046T,T1/2=15.1d,施药后37d消解85.0%,坡地低浓度级半衰期C=C0.e-0.090T,T1/2=7.7d,施药后15d消解74.2%。不同浓度森草净处理样地,施药后7、15、37d均可检测到嘧磺隆,并且含量越来越小,但施药后68d的土样,均未检测到嘧磺隆的存在。

The Mikania micrantha H. B. K. , a native to Central and South America, has becoming a noxious exotic invasive weed in the seashore areas in Guangdong Province and its neighbor Hong Kong, south China, especially in the Neilingding Island of Shenzhen City. In this paper, 9 plots and 81 sub-plots were selected as examples to study and control the invasive of Mikania micrantha in the different habitats and communities in the Neilingding Island. The test result shows that between concentration in 0. 0001 - 0.2 g·m^-2 of chemical herbicide sulfometuron-ethyl, the best result could be obtained in controlling Mikania Micrantha; Moreover, the effect of controlling Mikania Micrantha will be much strengthened as the increase of the dosage of chemical herbicide sulfometuron-ethyl. For instance, the sulfometuron-ethyl with the concentration at 0.05 --0.1 g·m^2 and 0.2 g·m^2 in the sloping and valley examples could show an effective result. In addition, a new method of distilling sulfometuron-methyl from the soil samples has been excogitated, and it has been used to determine the remnants of sulfometuron-methyl in the examples with Mikania Micrantha in Neilingding Island. Through the testing, it shows that half-life in the valley examples is C = Co·e^-.0083T, T1/2 = 8. 4 d, after 37d medicine used, however, it has decompounded 95.9 %. In sloping examples, its half-life of the higher concentration group is C = Co ·e^-0.046T, T1/2 = 15. 1 d, after 37 d, it has decompounded 85.0 % ; and its half-life of lower concentration group is C = CO ·e^ -0.090T, T1/2 = 7.70 d, after 15 d , it has decompounded 74. 2 %. From these samples, we found that the decompounding speed of sulfometuron-ethyl are very fast and quick, and it could be determined after using medicine for 7, 15 d, and 37 d, since its content became smaller than it was before. However, with HPLC examination in the different concentration and condition, there is no any sulfometuron-ethyl in the soil samples after using medicine for 68 d.