MDARD Michigan Core Pesticide Applicator Practice Exam

What is a primary disadvantage of wettable powders (W or WP)?

1. Easy to mix and measure

2. Not abrasive

3. Needs constant agitation when in suspension

4. Less likely to clog

The correct answer is: Needs constant agitation when in suspension

Wettable powders are formulated as fine, dry particles that need to be mixed with water to create a suspension for application. A primary disadvantage of these products is that they require constant agitation during use. This is because the particles tend to settle at the bottom of the spray tank if not kept in suspension, leading to uneven distribution of the active ingredient and potential ineffectiveness in pest control. Proper agitation ensures that the product remains evenly mixed, allowing for consistent application and maximizing the efficacy of the pesticide. Other characteristics of wettable powders, such as being easy to mix or measure and not being abrasive, are advantages rather than disadvantages. Additionally, while clogging can occur with various formulations, wettable powders generally have formulations designed to minimize that risk, making this another characteristic that does not align with the identified disadvantage.