Certified Crop Advisor Practice Exam

A day when there is _____ probability of precipitation would be best for pesticide application to minimize pesticide losses in runoff.

1. high

2. medium

3. less

4. constant

The correct answer is: less

Selecting a day with less probability of precipitation is advantageous for pesticide application because it decreases the likelihood of runoff that can carry pesticides away from the target area. When there is a high chance of rain, the risk of pesticide loss through water movement increases significantly, which not only reduces the effectiveness of the pesticide but can also contribute to environmental pollution. On days with high or medium probabilities of precipitation, there is a greater chance that rain will occur after application, leading to runoff that washes the pesticide off the fields before it can adequately act on pests or weeds. A constant probability may not effectively capture the chance of unexpected weather changes, making it less reliable than a day forecasted with a low chance of precipitation. By opting for a day with a less probability of precipitation, the application can be performed under more stable conditions, allowing the pesticide to remain on the intended areas longer, thereby enhancing its effectiveness and minimizing the risk of runoff and environmental contamination.