Which factor has no effect on off-target pesticide drift?

The factor identified as having no effect on off-target pesticide drift is a constant 3 mph wind. This indicates that if the wind speed is steady and not variable, it may not contribute to the unpredictable nature of drift that can occur with fluctuating or high wind speeds.

In contrast, high wind speeds can lead to significant drift because strong gusts can carry pesticide particles further away from the intended target area. Temperature fluctuations can also have an impact, as they may affect how pesticide droplets behave in the air. High temperatures can cause evaporation, altering the size and weight of droplets, which can increase the potential for drift. Similarly, humidity levels influence evaporation rates and can impact drift; low humidity can lead to faster evaporation, while high humidity can help droplets stay intact longer, affecting their flight path.

Therefore, while variations in wind speed, temperature, and humidity can play significant roles in the behavior of pesticide applications and their potential for drift, a consistent, low wind speed such as 3 mph is unlikely to contribute to off-target drift issues.