When should pesticide applications to avoid vapor drift be made?

Making pesticide applications at dawn or dusk is recommended to minimize the risk of vapor drift. During these times, temperatures are generally cooler, and there is often more humidity in the air. These conditions help reduce the volatility of pesticides, meaning they are less likely to evaporate and drift away from the target area. Additionally, wind speeds are often lower during dawn and dusk, further decreasing the likelihood of drift and enhancing the effectiveness of the application.

In contrast, applying pesticides during the heat of the day, particularly when temperatures rise above 85 degrees, can increase volatility and the potential for vapor drift, making it less ideal. Similarly, applying only during humid conditions is not a definitive guideline, as excessive moisture can also influence efficacy and drift. Sunny conditions typically lead to increased temperatures, heightened volatility of certain pesticide formulations, and can exacerbate the drift issue. Therefore, early morning or late evening conditions are strategically chosen to ensure more effective and safer pesticide applications.