Which pesticide formulations must be diluted before they are applied?

The correct answer is based on the nature of wettable powders and emulsifiable concentrates, which are designed to be diluted before application. Wettable powders are solid pesticides that need to be mixed with water to create a suspension for effective application. This ensures that the active ingredient is adequately dispersed in the solution, allowing for even coverage when applied to target pests.

Emulsifiable concentrates, on the other hand, are liquid formulations that require dilution with water to form an emulsion, which also enhances the distribution of the active ingredient during the application. Diluting these formulations is crucial to achieve the desired concentration and effectiveness while minimizing potential harm to the applicator and the environment.

This understanding highlights the importance of following label instructions for proper mixing and application. The other formulations mentioned, such as flowables, granules, aerosols, and fumigants, have different application requirements and may not necessitate dilution in the same way as wettable powders and emulsifiable concentrates.