有机硅提高除草剂在紫茎泽兰叶片上润湿性能的研究

市售的氨氯吡啶酸与甲嘧磺隆制剂用四川省西昌市当地自来水稀释1250、2500、5000、10000和625、1250、2500、5000倍后，得到的药液的表面张力大于紫茎泽兰的临界表面张力，药液滴与紫茎泽兰叶片的接触角在接触4min后仍为50°～70°。虽然氨氯吡啶酸和甲嘧磺隆对紫茎泽兰（Eupatorium adenophorum Spreng）防除效果较好，可喷药后药剂不容易被植物持留，造成巨大浪费和当地的环境污染。从农药应用角度来看，这两种农药制剂中表面活性剂存在不合理性。笔者通过添加有机硅表面活性剂，探索合理的有机硅添加浓度，减小氨氯吡啶酸、甲嘧磺隆与紫茎泽兰叶片的接触角，改善该药剂对紫茎泽兰叶片润湿性，提高其利用率，减少损失，避免环境污染。文章测定了有机硅临界胶束浓度、紫茎泽兰临界表面张力及添加不同浓度有机硅药液的表面张力，得到有机硅质量分数大于等于0．05％（有机硅临界胶束浓度），药液即可以在叶面铺展的结论。通过有机硅添加量与药液铺展速率的关系的测定，得到结论：有机硅添加质量浓度达到0．05％时，添加浓度越大，铺展速率越大。

Study on enhancement of wetting property of herbicide on Eupatorium adenophorum spreng leaves by silicone surfactant

When commercial formulations ofpicloram and sulfometureon methyl formulations were diluted to1 250、 2 500、 5 000、10 000 and 625、1 250,2 500、5 000 times with the local water taken from the city of Xichang in Sichuan Province, the surface tension of both solutions of picloram solution and sulfometureon methyl were bigger than the critical surface tension of Eupatorium adenophorum Spreng. The contact angles of the picloram solution and sulfometureon methyl solution on Eupatorium adenophorum Spreng leaves were 50°～ 70° after 4min contacted although the efficacies were satisfaced for control of Eupatorium adenophorum Spreng with picloram and sulometureon methyl solution, but, the drops from the two solutions on the leaves were not easy to be reserved, which led to run off and environmental pollution. In order to reduce the contact angle and to improve the wetting of the two herbicides on Eupatorium adenophorum Spreng, the reasonable concentrations of silicone sur-factant added to herbicides were studied. After three factors, e.g. the CMC of the silicon surfacan, the critical surface tension of Eupatoriura adenophorura Spreng and the surface tension of the solutions added the different concentrations of the solicon, were tested, an initial conclusion could be summarized that when ≥0.05% silicon was added to the solutions of two herbicides, the drops could be spreaded. The more silicon was added, the better wiring was obtained.