Wisconsin Pesticide Applicator Practice Test

What is the function of surfactants in pesticide application?

1. Bind pesticide to soil particles

2. Decrease the surface tension of water, allowing the water carrier to spread over the surface

3. Increase pesticide viscosity

4. Prevent pesticide evaporation

The correct answer is: Decrease the surface tension of water, allowing the water carrier to spread over the surface

Surfactants play a crucial role in pesticide application by decreasing the surface tension of water. This reduction in surface tension enhances the ability of the water carrier to spread more effectively over the target surface, whether it be plant leaves or soil. By improving the spreading capability, surfactants facilitate better coverage and penetration of the pesticide, ensuring that the active ingredients reach the intended targets more effectively. This is particularly important for achieving optimal pest control and ensuring uniform distribution of the pesticide, which maximizes its effectiveness. Other options contribute to various aspects of pesticide application, but they do not directly address the primary function of surfactants. For instance, while surfactants can influence how a pesticide interacts with soil particles, their main job is not binding pesticides to the soil. Increasing viscosity might modify how a pesticide is applied but is not a function of surfactants specifically. Additionally, while some formulation techniques can help prevent evaporation, surfactants are not primarily used for that purpose.