Which formulation requires agitation to maintain suspension for effective spraying?

Wettable powders are solid formulations designed to be mixed with water to form a suspension before application. They consist of finely ground particles that do not dissolve but rather suspend in the liquid. For effective spraying, it's crucial that these particles remain evenly distributed throughout the mixture.

Agitation is necessary because without it, the heavier particles will settle at the bottom of the spray tank, leading to an uneven distribution of the herbicide during application. This can result in inadequate coverage of the target area and reduced effectiveness of the application, which is why maintaining agitation is vital when using wettable powders.

In contrast, other formulations such as soluble concentrates dissolve completely in water, flowables have a different consistency that doesn't require the same level of agitation, and invert emulsions typically rely on their emulsified nature to maintain stability. Each of these alternatives may have specific handling requirements but do not necessitate the same continuous agitation as wettable powders do.