Structural Pest Control Applicator Practice Exam

If a pesticide is formulated only as a wettable powder and the target site has dense foliage, which sprayer should be used?

1. Low-pressure boom sprayer

2. High pressure sprayer

3. Ultra-low volume sprayer

4. Hand operated sprayer

The correct answer is: High pressure sprayer

When a pesticide is formulated as a wettable powder and the target site features dense foliage, using a high-pressure sprayer is the most suitable option. Wettable powders require adequate agitation to ensure that they are properly mixed with water and can remain suspended in the spray solution. A high-pressure sprayer generates sufficient force to break up the wettable powder and create a fine mist, which can effectively reach the dense areas of foliage. In addition, the high pressure helps in penetrating thick plant material, ensuring better coverage and greater contact with the pest. This penetration is crucial because if the pesticide does not reach the leaves or stems where pests may be residing, it may not be effective. Options involving low-pressure boom sprayers and hand-operated sprayers may not provide the necessary pressure to adequately disperse the wettable powder through dense vegetation. An ultra-low volume sprayer, on the other hand, is not appropriate for wettable powders as these formulations typically require more liquid to ensure proper coverage, which ultra-low volume equipment does not provide.