Which environmental factor can reduce the effectiveness of pesticides?

Rainfall shortly after the application of pesticides can significantly reduce their effectiveness. When it rains soon after a pesticide is applied, the moisture can wash away or dilute the pesticide before it has had a chance to adhere to or penetrate the target organisms or surfaces. This can result in lower pest control efficacy, as the active ingredients may not remain in contact with the pests long enough to do their work, or they may be completely washed away.

In contrast, sunny weather can help with the drying process, high humidity might enhance the effectiveness of some pesticides by slowing evaporation, and stable temperatures contribute to the optimal conditions for pesticide performance. However, the immediate impact of rainfall following application can create a substantial barrier to successful pest management.