Texas Pesticide Applicator Practice Exam

What weather conditions are conducive to reducing pesticide drift?

1. High winds, high temperatures, and low humidity

2. Lack of wind, low temperatures, and high humidity

3. Clear skies, no humidity, and high temperatures

4. Strong winds, high humidity, and cold temperatures

The correct answer is: Lack of wind, low temperatures, and high humidity

The weather conditions that are conducive to reducing pesticide drift include factors that help to keep the pesticides where they are intended to go, minimizing the chance of them being carried away by air movement. Lack of wind is particularly important because strong winds can easily transport pesticide particles away from the target area. Low temperatures can contribute to reducing drift as they often diminish the volatility of pesticide formulations, leading to less evaporation and potential drift into the air. High humidity also plays a crucial role because it can help to keep droplets of pesticide heavy and less prone to becoming aerosolized, further reducing movement away from the application site. In contrast, the other sets of conditions listed would likely contribute to increased drift. High winds and high temperatures can increase the likelihood of drift by dispersing the pesticide particles farther from the application area. Conditions with clear skies and no humidity may encourage evaporation and volatility, while strong winds would exacerbate drift, especially if combined with high humidity and cold temperatures, which could still allow particles to become airborne. Thus, the combination of lack of wind, low temperatures, and high humidity effectively minimizes drift and keeps pesticide applications more targeted.