成膜性助剂的叶面成膜机理及对农药药效和残留影响的内在机制

Film could be formed on plant leaves when foliar film-forming pesticide adjuvants were sprayed, which could increase the pesticide deposit and enhance pesticide adhesion to leaves. Meanwhile, it also could have some effect on the pesticide efficacy and residue. In this project, we will plan further research to three foliar film-forming protective pesticide adjuvants (turpentine oil, methyl esterification of turpentine oil and Pinolene) employed by pot experiments, intending to make it as the starting point to the physical properties and film-forming process of two new insecticides atomization on cabbage and rice leaf surface. It would be compared that impacts of different adjuvants on physical dynamics of pesticide droplets on cabbage and rice leaf surface. And the film-forming characteristics of different adjuvants would be clarified. Through the studies of the microscopic structure of leaf surface, pesticides initial deposited amount, the ability resistant to rain erosion , anti-UV test, virulence test, the specific activities of two enzymes ( carboxylesterase, CarE; glutathione S-transferase, GSTs ) related to the pest resistance to insecticides, pesticide residues in the different parts of leaf surface, et al, we will reveal the film-forming mechanism on leaf of adjuvants and the intra mechanism of the effect on efficacy and residue of insecticides. This study could provide new ways and the corresponding theoretical basis, supported by improving pesticide efficiently used, protecting the ecological environment, and reducing pesticide residues to improve agricultural food security; meanwhile, it could give systemic theoretical basis to make the foliar film-forming adjuvants used in large fileds.

叶面成膜性农药助剂喷施后可在植物叶表形成保护膜，提高农药叶面沉积量及增强附着力，同时通过其成膜特性对农药的药效和残留产生一定的影响。本项目拟以两种新型杀虫剂的喷雾雾滴在甘蓝和水稻叶面上的物理性状和成膜过程为着手点，采用盆栽实验，针对三种叶面成膜保护性农药助剂（松脂油、甲酯化松脂油和Pinolene）进行深入研究。比较不同助剂对农药雾滴在甘蓝和水稻叶表面物理动态的影响，阐明不同助剂的成膜特性，并通过对叶表面微观结构、农药原始沉积量、耐雨水冲刷能力、抗紫外光解、毒力测定、虫体内与抗性有关的羧酸酯酶(CarE)和谷胱甘肽S-转移酶(GSTs)的比活力变化、农药残留在叶表迁移规律等方面的研究，揭示成膜性农药助剂的叶面成膜机理及对药效和残留影响的机制。为提高农药利用效率、保护生态环境，同时减少残留、提高农产品的食用安全性，提供新途径和相应理论支撑；也为叶面成膜性助剂的大面积推广使用提供系统理论依据。

关于助剂影响深层次的作用机理研究还不多，特别是关于叶面成膜保护性助剂，目前国内外鲜有报道。叶面成膜性农药助剂喷施后可在植物叶表形成保护膜，提高农药叶面沉积量及增强附着力，同时通过其成膜特性对农药的药效和残留产生一定的影响。本项目以两种新型杀虫剂的喷雾雾滴在甘蓝和水稻叶面上的物理性状和成膜过程为着手点，采用盆栽实验，针对三种叶面成膜保护性农药助剂（松脂油、甲酯化松脂油和Pinolene）进行深入研究。比较不同助剂对农药雾滴在甘蓝和水稻叶表面物理动态的影响，阐明不同助剂的成膜特性，并通过对农药原始沉积量、耐雨水冲刷能力、抗紫外光解、毒力测定、农药残留在叶表迁移规律等方面的研究，揭示成膜性农药助剂的叶面成膜机理及对药效和残留影响的机制。结果显示，松脂油助剂的加入使药液的干燥时间显著延长；甲酯化松脂油影响不大；Pinolene使干燥时间从51.3 min缩短到45.4 min。甲酯化松脂油和Pinolene，在添加浓度分别为0.10%和0.05%时，叶面农药沉积量分别提高了6.2倍和5.5倍。三种助剂人工模拟降雨后，沉积量分别为原来的22.5%(Pinolene)、28.3%(甲酯化松脂油)和41.1%(松脂油)，均大于对照。三种助剂均能促进甲氨基阿维菌素苯甲酸盐的光解。毒力试验表明三种助剂对茚虫威具有明显的增效作用，3种助剂相互之间没有显著差异。在助剂的作用下农药即迅速向叶面蜡质层渗入，加助剂比不加助剂对照高1.7—2.3倍，之后向叶内层渗入速度显著放缓，松脂油、甲酯化松脂油和Pinolene处理分别使甲氨基阿维菌素苯甲酸盐向叶内层渗入了25%、18%和10%。三种助剂排序为松脂油>甲酯化松脂油>Pinolene。本项目为提高农药利用效率、保护生态环境，同时减少残留、提高农产品的食用安全性，提供新途径和相应理论支撑；也为叶面成膜性助剂的大面积推广使用提供系统理论依据。