Apart from external factors, what is the most important factor affecting off-target drift?

The size of spray droplets is the most important factor affecting off-target drift because it directly influences how far and in what manner the pesticide particles are carried away from the intended application area. Smaller droplets are more susceptible to being carried by wind, which can lead to drift and unintended deposition of pesticides on non-target areas, such as nearby crops, water bodies, or residential areas.

In aerial application, managing droplet size is crucial. Larger droplets tend to fall quickly to the ground, reducing the chance of off-target drift. Therefore, understanding and controlling the droplet size through nozzle selection, pressure settings, and other application techniques can significantly mitigate drift risks.

While weather conditions, the type of pesticide used, and the equipment can all play a role in drift, it is the droplet size that has the most direct impact on drift behavior during the actual application process. This makes it essential for applicators to focus on optimizing droplet size to ensure effective and responsible application of pesticides.