不同喷雾助剂在植保无人机喷施作业中对雾滴沉积特性的影响

Effects of different spray additives on droplet deposition characteristics during plant protection UAV spraying operations

为研究不同喷雾助剂的理化性质及喷雾助剂在玉米叶片上的沉积特性,该研究将6种喷雾助剂对药液表面张力、药液在玉米叶片上接触角以及无人机喷施6种不同的喷雾助剂对雾滴的沉积特性进行对比。结果表明:喷雾助剂可以显著降低(P=0.000)溶液的表面张力,与清水溶液的表面张力相比Starguar4A喷雾助剂对降低溶液表面张力的作用效果最好,降低了67.8%。喷雾助剂对溶液在玉米叶片上接触角的变化程度影响不同,随着时间的增加雾滴在玉米叶片上的接触角均逐渐降低,其中Ultimate喷雾助剂的雾滴在滴落到玉米叶片上90 s后接触角降低至0°。与清水溶液相比倍达通喷雾助剂的雾滴密度、覆盖率与沉积量作用效果最好,雾滴密度与覆盖率、沉积量分别提高了35.1%、93.8%、31.9%;添加喷雾助剂后除倍达通喷雾助剂外,其他喷雾助剂溶液的雾滴体积中径DV0.5均有所降低;添加喷雾助剂对雾滴谱宽的影响不明显。在田间进行无人机植保喷施作业时,可以优选使用倍达通喷雾助剂,虽然倍达通喷雾助剂的表面张力与接触角并不是最优,但是也能够满足田间使用植保无人机喷雾作业的要求。同时,该试验也为进一步提高农药的利用率提供数据参考。

With the rapid development and application of plant protection UAV in China,its high-efficiency and low-volume spraying technology has gradually become a research hotspot.At present,domestic and foreign researches on spray additives for plant protection UAV are mainly based on droplet drift and laboratory tests.Few studies have been conducted on the physical and chemical properties of spray additives and the effects of droplet deposition characteristics.Spray additives can reduce the surface tension of the solution and increase the retention of droplets,which is of great significance for improving the utilization of pesticides.Therefore,this study explored the effects of different spray additives on the surface tension of the solution,the change law of the contact angle of the solution on the maize leaves,and the droplet deposition characteristics.In the experiment,surface tension-meter,contact angle measurement,723S visible spectrophotometer,and XAG XP2020 plant protection UAV were used to measure the surface tension,contact angle,droplet deposition characteristics,and other parameters of six kinds of aviation spray additives(Ultimate,Starguar4A,Starguar4,Bei Datong,Mai Fei,Atplus Mso-Hs 500).Kromekote cards and Mylar were used to sample the droplet deposition characteristics,and DepositScan software was used to measure the droplet density,coverage,DV0.5 and other parameters on the Kromekote cards.The test results showed that the addition of spray additives could significantly reduce the surface tension of the solution and had a significant difference(P=0.000).The surface tension value of the solution after adding the spray additives was reduced by 56.4%-67.8%compared with the pure water solution.Among them,Starguar4A spray additives had the best effect on reducing the surface tension of the solution,but it was not significant difference effects of Ultimate spray additives.The spray additives had different effects on the contact angle of the solution on the maize leaves.The contact angle of the pure water solution on the maize leaves varies from 111.27°to 108.10°.With the increase of time,the contact angle of the spray additive solution on the maize leaves gradually decreases and Ultimate spray additive had the best effect,and the contact angle decreased to 0°after the droplets fall on the corn leaves for 90 s.Adding spray additives can increase the density and coverage of the droplets in the deposition area and sampling area,among which the effect of Be Datong spray additives was the best,and the density and coverage of droplets and deposition were increased by 35.1%,93.8%and 31.9%respectively compared with the pure water solution.The deposition of the deposition area after adding spray additives varies from 0.049-0.072μL/cm^(2),which is increased compared with the pure water solution.Among them,the deposition of Bei Datong spray additives was up to 0.072μL/cm^(2).The distribution of the deposition amount of the droplets with the sampling position basically conforms to the normal distribution.After adding spray additives,the DV0.5 of most of the additive solutions had been reduced and there was a significant difference(P<0.05).Except for the increase of droplet DV0.5 by Bei Datong,other spray additives all reduce droplet DV0.5,generally reducing by about 50μm.Adding spray additives had no obvious influence on the droplet relative span,and there was no significant difference compared with the pure water solution(P<0.05).When plant protection spraying operations were carried out in the field,it can be preferable to use Bei Datong spray additives.Although the surface tension and contact angle of Bei Datong spray additives are not optimal,it can also meet the needs of field use of UAV.Meanwhile,the test can also provide a data basis for further improving the utilization rate of pesticides.