MDARD Michigan Core Pesticide Applicator Practice Exam

Which factor does NOT influence the amount of spray drift during pesticide application?

1. Droplet size

2. Liquid thickness

3. Type of soil

4. Height of application

The correct answer is: Type of soil

The correct choice indicates that the type of soil does not influence the amount of spray drift during pesticide application. Spray drift primarily occurs when airborne particles of pesticide are carried away from the target area by wind or are subject to gravitational forces. Factors that are critical to spray drift include droplet size, liquid thickness (viscosity), and the height at which the application is made. Droplet size is significant because smaller droplets are more susceptible to drifting due to their reduced weight and larger surface area relative to volume, making them more easily carried by the wind. Liquid thickness refers to the viscosity of the pesticide formulation; less viscous liquids can create smaller droplets and are more prone to drift. The height of application is also crucial, as sprays released from a greater height have more time to be affected by wind currents before reaching the target area, increasing the potential for drift. In contrast, the type of soil does not play a direct role in the mechanics of spray drift, as it pertains more to the absorption and retention of the pesticide once applied to the ground rather than its dispersion in the air during application. Therefore, it is accurate to say that type of soil does not influence spray drift.