Which two factors should pesticide applicators consider to avoid spray drift?

• A. Viscosity of liquid pesticides and air turbulence
• B. Temperature and pesticide volatility
• C. Air stability and temperature
• D. Droplet size and wind direction and speed

Answer: (D)

Pesticide applicators need to be particularly mindful of factors that contribute to spray drift to effectively manage applications and ensure safety. The choice that emphasizes droplet size along with wind direction and speed addresses critical aspects of drift control.

Droplet size is essential because smaller droplets have a greater potential to remain airborne longer, increasing the likelihood of drifting away from the target area. Droplets that are too fine can be carried off by even light winds, resulting in unintended exposure to non-target areas, including neighboring crops, wildlife, or residential zones.

Wind direction and speed also play a vital role in drift potential. Applicators must be aware of the prevailing winds when applying pesticides, as strong winds can carry droplets off course, while the direction of the wind can determine the distance the spray will travel from the intended application site. By understanding and monitoring these factors, applicators can adjust their methods to minimize drift effectively, such as by selecting appropriate days for application when wind conditions are favorable and by using equipment that produces larger droplets.

In summary, focusing on droplet size together with wind direction and speed enables pesticide applicators to create a more controlled application environment, reducing the risk of drift and improving overall efficacy.