Associate Certified Entomologist (ACE) Practice Exam

When mixing multiple pesticide formulations, which should be added first?

1. Emulsifiable concentrates

2. Flowables and dry flowables

3. Water-soluble concentrates

4. Wettable powders

The correct answer is: Wettable powders

When mixing multiple pesticide formulations, the recommended order often starts with wettable powders. This is due to their formulation characteristics, as wettable powders need to be thoroughly suspended in the mix. Starting with wettable powders allows for proper dispersion and mixing before the addition of other formulations. When added first, wettable powders can effectively dissolve in water, ensuring that they do not settle at the bottom of the mixing container. This helps prevent clumping and ensures a uniform distribution of the product, which is crucial for effective pest control. The other formulations typically rely on different principles of mixing. Emulsifiable concentrates and water-soluble concentrates may require different handling and mixing protocols, and if added before the wettable powders, they might not incorporate well. Flowables and dry flowables also have their own mixing needs that can be affected by the order of addition. Therefore, beginning the mix with wettable powders is a best practice to promote effective blending and application.