Minnesota Pesticide Applicator Practice Test

Which term describes chemicals that enhance pesticidal performance but do not have pesticidal activity?

1. Adjuvants

2. Fumigants

3. Repellents

4. Emulsifiable concentrates

The correct answer is: Adjuvants

Adjuvants are substances that are added to pesticide formulations to improve their performance without having any inherent pesticidal properties. They can enhance the effectiveness of the active ingredients by facilitating better coverage, increasing adherence to the target surface, improving the ability of the pesticide to penetrate or be absorbed by the pest, or allowing for more effective dispersion of the pesticide in solution. Examples of adjuvants include surfactants, spreaders, stickers, and emulsifiers, which modify the physical or chemical properties of the pesticide application. The other terms describe different types of pesticide formulations or their functions. Fumigants are volatile substances that can penetrate soil or plant tissues to control pests in a gaseous form. Repellents are chemicals designed to deter pests from approaching plants or surfaces, often by creating an unpleasant sensory response. Emulsifiable concentrates refer to a specific formulation type of pesticide that can be mixed with water to form an emulsion, but these do not serve to enhance the pesticidal activity of the product itself.