Illinois Pesticide Applicator Practice Test

When is it advisable to stop spraying to avoid pesticide drift?

1. During intense rainfall

2. When the soil is dry

3. When wind conditions are unstable

4. When temperatures are high

The correct answer is: When wind conditions are unstable

Choosing to stop spraying when wind conditions are unstable is crucial for preventing pesticide drift. Stable wind conditions help ensure that the spray remains directed toward the target area, minimizing the chance of unintended drift to non-target areas, such as neighboring crops, water bodies, or residential properties. Unstable wind can lead to sudden gusts or changes in direction, which can carry the pesticide farther than intended, increasing the risk of contamination or harm. In contrast, while intense rainfall might seem like a logical time to stop spraying since it can wash away the pesticide, it does not specifically address the issue of drift caused by the wind. Similarly, dry soil conditions do not inherently influence drift and are more connected to the effectiveness of the pesticide application rather than the risk of drift itself. High temperatures can affect pesticide volatility and evaporation but are not primarily related to wind conditions that facilitate drift. Therefore, recognizing and responding to unstable wind conditions is the most effective action to prevent pesticide drift during application.