MDARD Michigan Core Pesticide Applicator Practice Exam

What property of surfactants enhances the effectiveness of pesticide mixtures?

1. Effective odor masking

2. Stability in extreme temperatures

3. Wetting and spreading the spray droplets

4. Increasing vapor pressure

The correct answer is: Wetting and spreading the spray droplets

The effectiveness of pesticide mixtures is significantly enhanced by the property of surfactants that allows them to wet and spread spray droplets. Surfactants, or surface-active agents, reduce the surface tension of water, enabling droplets to spread more evenly over the surface of the target area, such as plant leaves or soil. This increased spreading improves coverage, ensuring that the pesticide can penetrate more effectively into the surface and adhere to the target organism or substrate. When the droplets are smaller and spread out more widely, they have a better chance of reaching and affecting pests or weeds, leading to improved efficacy of the pesticide. In addition to better coverage, surfactants can also facilitate the absorption of the pesticide into plant tissues, further enhancing its effectiveness. The other properties, such as odor masking, stability in extreme temperatures, or increasing vapor pressure, do not directly contribute to the performance of pesticide mixtures in the same impactful manner as the wetting and spreading ability of surfactants.