What primary aspect must be monitored to control drift during aerial application?

To effectively control drift during aerial application, it is crucial to monitor all the listed factors—type of pesticide, weather conditions, and size of droplets—since they each play a significant role in how pesticides behave once they are released into the air.

The type of pesticide is important because different chemicals have varying potential for volatility and drift. Some products are formulated to reduce drift risk, while others may be more prone to it under certain conditions.

Weather conditions, such as wind speed and direction, temperature, and humidity, have a direct impact on drift. High winds can carry pesticide particles further than intended, while temperature inversions can trap pesticide droplets in a layer, leading to more drift.

The size of droplets is also a critical factor since smaller droplets are more susceptible to being carried away by the wind. Larger droplets tend to fall more rapidly to the target area, reducing the likelihood of drift.

Monitoring all of these aspects is essential for responsible aerial application practices to minimize impact on non-target areas and ensure effective pest control. Therefore, all the listed elements work in concert to effectively manage drift during aerial pesticide application.