Oklahoma Service Technician Practice Exam

What droplet size is least likely to drift when applied?

1. Fine

2. Medium

3. Coarse

4. Very Coarse

The correct answer is: Very Coarse

The least likely droplet size to drift when applied is very coarse. The reason for this lies in the physical behavior of droplets in the air. Larger droplets have greater mass and are subject to the force of gravity more than smaller droplets. As a result, they are less susceptible to being carried away by wind or air currents, which can cause drift—an unintended movement of the pesticide away from the target area. Very coarse droplets settle more quickly to the ground after being released, reducing the time they are airborne and therefore minimizing the risk of drift. This aspect is especially important in agricultural settings and residential areas where it’s vital to control where pesticide residues end up to avoid impacting unwanted areas or neighboring properties. In contrast, fine and medium droplets remain airborne longer due to their smaller size, making them more prone to drift. Coarse droplets, while less likely to drift than fine or medium, still present a moderate risk compared to very coarse droplets. Thus, choosing very coarse droplets for application is a strategy to enhance efficacy while minimizing environmental exposure.