Which type of adjuvant increases the viscosity of spray mixtures?

• A. Thickeners
• B. Surfactants
• C. Emulsifiers
• D. Buffers

Answer: (A)

Viscosity is about how thick a liquid is and how easily it flows. Thickeners are adjuvants that raise the viscosity of spray mixtures by adding thickening agents, such as cellulose derivatives or gums. A higher viscosity makes the spray flow more slowly, which helps reduce drift and helps the liquid stay on the target long enough for the pesticide to work. Surfactants modify how well the spray wets and spreads on surfaces, so they primarily affect wetting rather than thickness. Emulsifiers help mix liquids that don’t normally mix, but they don’t primarily increase thickness. Buffers adjust the pH of the mix, not its viscosity.