Which pesticide treatment would be least likely to be affected by rain shortly after application?

Granular application is the treatment least likely to be affected by rain shortly after application. This is primarily because granular pesticides are solid particles that settle on the target area and adhere to surfaces, making them less susceptible to being washed away by rainfall compared to liquid formulations.

Liquid sprays, fogging, and aerosol sprays consist of liquid droplets that can easily be disrupted by rain. When these liquid treatments are applied, they require sufficient time to dry and bond to the surfaces they are intended to treat. If rain occurs shortly after the application, it can dilute the pesticide, wash it away, or prevent it from effectively adhering to the surfaces, rendering the treatment less effective.

Therefore, due to the physical properties of granular pesticides, they are more resilient against the impact of rain immediately following their application compared to the liquid forms, making granular application the best choice in this scenario.