What is an important visual sign left by a wettable powder after application?

A visible residue is a crucial visual sign left by a wettable powder after application because it indicates that the product has been successfully dispersed and adhered to the targeted surface. This residue is often an indicator of effectiveness, showing that the active ingredients are present in the application area and allows the applicator to confirm that the treatment has been applied as intended.

The presence of a visible residue can also serve as a reminder for future applications and help to ensure proper coverage of the treatment area. Such indicators are important for both practitioners and end-users, providing confidence that the application was thorough and that the powder will perform its intended function, such as pest control or disease management in agricultural settings.