【摘要】 研究了苹果叶片-苹果黄蚜-药液三者之间的互作关系,为吡虫啉田间应用减量提供数据支持。通过电镜扫描表征苹果新梢叶片表面结构特性,采用WORK(Owens-Wendt-Rabel-Kaelble)法预测叶片表面自由能,并通过药效试验研究三者之间的互作关系。结果表明:叶片近轴面表面自由能显著高于远轴面,且均以色散分量为主。远轴面和近轴面表面覆盖有大量茸毛,茸毛的密度影响表面自由能。助剂浓度增加,吡虫啉3 000倍稀释液的表面张力由42.72 mN/m下降到22.87 mN/m,药后3 d对苹果黄蚜的田间防效由80.27%上升到94.25%。苹果新梢叶片近轴面和远轴面属于疏水表面,易被以色散分量为主的非极性溶剂润湿。当喷雾药液的表面张力值接近于苹果新梢叶片表面自由能值时,药液易铺展润湿。吡虫啉防治苹果黄蚜时,喷雾药液表面张力应为20～30 mN/m。更多还原

【Abstract】 The aim of the study is to investigate the relationship between surface characteristic and surface free energy(SFE) of apple shoots leaves and provide usage information for the application of imidacloprid insecticide. The surface characteristics of apple shoots leaves were tested by electron microscope and the surface free energy of apple shoots leaves were predicted by OWRK(Owens-Wendt-Rabel-Kaelble) method. The interaction among the three factors was confirmed with field efficacy test. The result showed that there are plenty of pubescence on the adaxial and abaxial surfaces of apple shoots leaves. The number of the pubescence on the abaxial surface was more than the abaxial.The abaxial surface is covered with high-density pubescence,which are prostrate distributed irregularly. The SFE of the adaxial of the apple young leaves were higer than the abaxial. The SFE is dominated by dispersion components. With increasing the concentration of surfactant,the surface tension value of sprayed liquids at the recommended concentration of 3 000-fold solution declined from 42.72 mN/m to 22.87 mN/m and the field efficacy after sprayed three days rised from 80.27% to 94.25%. The adaxial and abaxial surfaces of apple shoots leaves belong to hydrophobic surfaces, which are easily wetted with non-polar solvents that dominated by dispersion components. When the surface tension value of the sprayed liquids is close to the SFE value of the apple shoots leaves, the sprayed liquids is easier to spread and wet on the apple shoots leaves surface. In the field application of imidacloprid insecticide against Aphis citricola, we should choose the appropriate spraying additives, pesticide formulation and dosage according to the SFE value of apple shoots leaves. When the surface tension value of sprayed liquids was close to about 20～30 mN/m, the sprayed liquids is easier to spread and wet on the apple shoots leaves surface and improve the effect of pesticide deposition on the target surface and attain the goal of reducing.更多还原