What is a key feature of wettable powders in pesticide formulations?

A key feature of wettable powders in pesticide formulations is that they require agitation to remain suspended in water. Wettable powders consist of finely ground, solid formulations that do not dissolve completely but can be dispersed in water when agitated. This characteristic is essential because it ensures that the pesticide remains uniformly distributed in the spray solution during application. If the suspension is not adequately agitated, the powders may settle at the bottom, leading to uneven application and reduced effectiveness.

The other options do not accurately represent the properties of wettable powders. For example, these formulations are not highly volatile, meaning they do not easily evaporate into the air. They also do not dissolve immediately in any liquid, as they are meant to remain in suspension, and while they can be used in soil treatments, that is not their primary purpose—wettable powders are often employed for various application methods, including foliar treatments.