MDARD Michigan Core Pesticide Applicator Practice Exam

Which type of adjuvant functions as a wetting agent and spreader?

1. Thickener

2. Surfactant

3. Surfacing agent

4. Emulsifier

The correct answer is: Surfactant

A surfactant functions as a wetting agent and spreader by reducing the surface tension of liquids, allowing them to spread more easily on surfaces, such as leaves or soil. This property is essential in pesticide applications, as it enhances the coverage and effectiveness of the pesticide. When added to a pesticide formulation, surfactants help the active ingredients to adhere better to the target area, which maximizes the product's effectiveness by ensuring that a uniform layer covers the surface, leading to improved absorption and activity. In contrast, thickeners are primarily used to adjust the viscosity of a formulation, while emulsifiers help to stabilize mixtures of oil and water but do not effectively act as wetting agents in the same way. Surfacing agents are not specifically recognized as a standard term in pesticide application, which makes the surfactant the clear choice here for achieving improved spreading and wetting properties.