田间药液用量影响农药单位剂量防治效果的原因分析  

The Cause of Influence of Spray Volume on Control Effect of Pesticide Unit Dose in Rice Fields

作　　者：顾中言[1] 徐德进[1] 徐广春[1] GU ZhongYan;XU DeJin;XU GuangChun(Institute of Plant Protection,Jiangsu Academy of Agricultural Sciences,Nanjing 210014)

机构地区：[1]江苏省农业科学院植物保护研究所,南京210014

出　　处：《中国农业科学》2018年第13期2513-2523,共11页Scientia Agricultura Sinica

基　　金：国家重点研发计划(2017YFD0200305);江苏省农业科技自主创新资金(cx(16)1001)

摘　　要：【目的】分析药液用量与水稻植株持液量的关系,探索稻田药液用量影响农药单位剂量防治效果的机制,为科学使用农药提供依据。【方法】在喷雾状态下计量水稻单位面积的持液量变化,明确液体在水稻叶片上的流失点和稳定持液量。依照国家标准GB/T 5549^(-2)010测定液体表面张力,利用表面活性溶液的表面张力随表面活性剂浓度变化的规律,测定表面活性剂溶液的临界胶束浓度;用Zisman的方法测定水稻叶片的临界表面张力,分析影响水稻叶片持液量的关键因子。在喷雾塔内模拟用氯虫苯甲酰胺防治稻纵卷叶螟、用吡蚜酮和毒死蜱防治褐飞虱的试验,分析药液用量与雾滴密度的关系及农药单位剂量对防治效果的影响。【结果】随着喷液量的增加,水稻叶片的持液量经历增加、达到最大值后开始流失、随之下降到稳定值并不再随喷液量而变化,与最大值比,稳定值减少持液量约50%。供试水稻的临界表面张力为29.90—31.22 m N·m^(-1),为低能表面,清水的表面张力为71.8m N·m^(-1),大于水稻的临界表面张力,限制了水稻叶片的持液量;助剂TX^(-1)0和Silwet-408可使液体的表面张力小于水稻临界表面张力,增加水稻叶片的持液量,当助剂达到临界胶束浓度时,增加持液量的效果最好;喷液量影响雾滴密度,从而影响农药单位剂量的防治效果。雾滴体积中径为200μm时,药液量150 L·hm^(-2)的雾滴少于10滴/cm2,20、25和30 g 3个有效剂量的氯虫苯甲酰胺对稻纵卷叶螟的防治效果不足60%;药液量450 L·hm^(-2)的雾滴少于40滴/cm2,氯虫苯甲酰胺3个有效剂量对稻纵卷叶螟的防治效果分别为56.92%、62.86%和65.07%;药液量900 L·hm^(-2)的雾滴为82滴/cm2,氯虫苯甲酰胺3个有效剂量对水稻纵卷叶螟的防治效果最好,达到70%以上。减小雾滴体积中径,增加单位体积液体的雾滴数量,可以适量减少喷液量。雾滴体积中径为75【Objective】The objective of this study is to analyze the relationship between the spray volume in rice fields and retention on rice plants, understand the mechanism affecting the control effect of pesticide unit dose, and to provide a basis for thescientific use of pesticides. 【Method】 The liquid retention on unit area of rice was measured under spraying conditions, the change of the liquid retention indicated the point of run-off and maximum retention of the liquid on rice leaves. The surface tension of the liquid was measured by the method according to the GB/T 5549^-2010, and the critical micelle concentration of the surfactant solution was determined by using the law of the surface tension varying with the concentration of the surfactant. The Zisman method was used to measure the critical surface tension of rice leaves. The key factors affecting the leaf capacity of rice leaves were analyzed. By simulating chlorantraniliprole control of rice leaf roller（Cnaphalocrocis medinalis）, pymetrozine and chlorpyrifos control of brown planthopper（Nilaparvata lugens） in a spray tower, the relationship between spray volume and droplet density and the effect of pesticide unit dosage on control effect against pests were also investigated. 【Result】 With the increase of the spray volume, the liquid holding capacity of rice leaves increased. After reaching the maximum value, the liquid began to lose and then it decreased to a stable value and no longer changed. The final liquid holding capacity was only 50% of the maximum value. The critical surface tension of the tested rice leaves was 29.90-31.22 m N·m^-1, which meant the tested surface was a low-energy surface. The surface tension of clear water was 71.8 mN ·m^-1, which was greater than the critical surface tension of the tested surface. The surface tension of tested rice leaves limited the liquid holding capacity of the leaves. With the additives TX^-10 and Silwet-408, the surface tension of the liquid was less than the critical surface tension of ri

关 键 词：农药 药液用量 流失点 持液量 雾滴密度 防治效果 

分 类 号：S48[农业科学—农药学]