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

The concept of off-target pesticide drift is significantly affected by environmental conditions, as these factors can influence how pesticides are dispersed during application. When considering the choices provided, the constant 3 mph wind is a condition that has a predictable and steady impact on drift potential, as wind can carry pesticide droplets away from the intended target area.

In contrast, other factors like wind speed, humidity levels, and temperature can vary widely and create conditions for drift. For example, varying wind speeds can lead to increased drift potential, higher temperatures may cause faster evaporation of spray particles, and humidity can affect droplet size and evaporation rates.

Since the constant 3 mph wind represents a stable condition rather than a variable factor that could change and affect drift potential, it can be considered as having no effect on off-target drift in a direct sense. Thus, it serves as a baseline scenario where drift could be evaluated under consistent wind conditions.