Which of the following is NOT true about soluble powders?

The assertion that soluble powders cannot be used for foliar applications is not true because soluble powders are designed to dissolve in water, creating a solution that can be applied to plant surfaces for various purposes, including foliar feeding and pest control. When mixed correctly with water, these powders can efficiently deliver nutrients or pesticides directly to leaves.

In addition, soluble powders do dissolve in water, forming a homogeneous solution, which is crucial for consistent application. Proper mixing is necessary to ensure that the soluble powders activate and dissolve completely, preventing clogs or uneven distribution during application. While soluble powders might leave some residues on surfaces after application, this characteristic isn't universally detrimental and may be managed based on the context of their use.