Fritz Bradley K, Hoffmann W Clint
Aerial Application Technology Research Unit, USDA ARS;
Aerial Application Technology Research Unit, USDA ARS.
J Vis Exp. 2016 Sep 16(115):54533. doi: 10.3791/54533.
When making an application of any crop protection material such as an herbicide or pesticide, the applicator uses a variety of skills and information to make an application so that the material reaches the target site (i.e., plant). Information critical in this process is the droplet size that a particular spray nozzle, spray pressure, and spray solution combination generates, as droplet size greatly influences product efficacy and how the spray moves through the environment. Researchers and product manufacturers commonly use laser diffraction equipment to measure the spray droplet size in laboratory wind tunnels. The work presented here describes methods used in making spray droplet size measurements with laser diffraction equipment for both ground and aerial application scenarios that can be used to ensure inter- and intra-laboratory precision while minimizing sampling bias associated with laser diffraction systems. Maintaining critical measurement distances and concurrent airflow throughout the testing process is key to this precision. Real time data quality analysis is also critical to preventing excess variation in the data or extraneous inclusion of erroneous data. Some limitations of this method include atypical spray nozzles, spray solutions or application conditions that result in spray streams that do not fully atomize within the measurement distances discussed. Successful adaption of this method can provide a highly efficient method for evaluation of the performance of agrochemical spray application nozzles under a variety of operational settings. Also discussed are potential experimental design considerations that can be included to enhance functionality of the data collected.
在施用任何作物保护材料（如除草剂或杀虫剂）时，施药者会运用各种技能和信息来进行施药操作，以使材料到达目标部位（即植物）。在此过程中至关重要的信息是特定喷雾喷嘴、喷雾压力和喷雾溶液组合所产生的液滴大小，因为液滴大小会极大地影响产品功效以及喷雾在环境中的移动方式。研究人员和产品制造商通常使用激光衍射设备在实验室风洞中测量喷雾液滴大小。本文介绍的工作描述了在地面和空中施药场景下，使用激光衍射设备进行喷雾液滴大小测量的方法，这些方法可用于确保实验室间和实验室内的精度，同时将与激光衍射系统相关的采样偏差降至最低。在整个测试过程中保持关键测量距离和同步气流是实现这种精度的关键。实时数据质量分析对于防止数据出现过大变化或错误数据的额外混入也至关重要。该方法的一些局限性包括非典型的喷雾喷嘴、喷雾溶液或施药条件，这些会导致喷雾流在所述测量距离内无法完全雾化。成功采用这种方法可为评估各种操作环境下农用化学喷雾施药喷嘴的性能提供一种高效方法。文中还讨论了可纳入的潜在实验设计考量因素，以增强所收集数据的功能。
