茶皂素对农药的增效机理 Ⅱ.对药液接触角的影响

Synergistic Mechanism of Tea Saponin on Pesticides Ⅱ Influence on the Contact Angles of pesticide Solutions

测定了茶皂素对草甘膦、杀虫双、乐果、托尔克、Ｂｔ和氰戊菊酯等６种农药分别在马唐、水稻、小白菜、柑桔、芥蓝等５种植物和小菜蛾、菜青虫等２种害虫的体表接触角的影响。结果表明，茶皂素对上述几种农药水溶液液滴在植物和害虫的体表接触角均有不同程度的降低，从而提高了药液在靶标体表的湿展力和附着力，减少农药的损失，提高药效。特别是对于Ｂｔ在芥蓝叶背、草甘膦在马唐叶正面、氰戊菊酯在菜青虫体表等处理，其单剂接触角在１０６°以上，加入浓度为１０００～４０００ｍｇ／Ｌ的茶皂素后均下降到７８°以下，这在生产实际应用中具有重要的指导意义。

Influences of tea saponin on the contact angle of 6 pesticide(glyphosate,dimephypo,dimethoate,torque,Bt and fenvalerate)solutions on the leaf surface of 5 plant(crabgrass,rice,Chinese cabbage,citrus,and Chinese kale)and the body surface of 2 insect pests(diamondback moth and imported cabbage worm)were determined.Results showed that tea saponin could reduce the contact angle of pesticide solutions on the surface of plant leaves and insects in varying degree.So the adhesion,wetting and spreading properties of pesticide solutions on the surface of targets were increased,the loss of pesticides was decreased and effects of control were improved.Especially to the treatments of Bt on the undersurface of Chinese kale leaf,glyphosate on the surface of crabgrass leaf,and fenvalerate on the body surface of cabbage worm,the contact angles of pesticide solutions were above 106°,but they decreased to 78° below when 1 000 ～ 4 000 mg/L tea saponin was added.It had very important instructional significance in practice.