Which of the following can lead to unintended pesticide drift?

Unintended pesticide drift primarily occurs due to environmental factors, with wind and air movement being significant contributors. When pesticides are applied aerially, the presence of wind can carry fine droplets away from the targeted area, leading to unintended exposure of non-target crops, plants, or even people. This drift can occur as the pesticide is released into the air and can be influenced by the speed, direction, and turbulence of the wind at the time of application.

In contrast, using the correct nozzle type, choosing optimal times for application, and calibrating equipment are practices aimed at minimizing pesticide drift. These strategies help ensure that the pesticides are applied effectively and directly to the target area, reducing the chances of drift caused by air movement. Therefore, while these practices are essential for responsible pesticide application, they do not contribute to drift in the way that unpredictable wind conditions do.