A type of adjuvant that makes spray mixtures thicker is called:

• A. Wetting Agent
• B. Surfactant
• C. Sticker
• D. Emulsifier

Answer: (C)

Adjuvants modify how a spray behaves on plant surfaces. A sticker is a film-forming, sticky additive that coats the leaf after application, creating a tacky film that helps the pesticide stay in place and resist washing off by rain or irrigation. That adhesion gives the spray a “thicker” residue on the surface, which is why it’s described as making the mixture thicker in effect, even though it isn’t changing the solution’s viscosity in the nozzle or during spraying.

Wetting agents or surfactants work by reducing surface tension to improve spreading and coverage, not by increasing how long the residue remains attached. Emulsifiers help mix immiscible liquids, like oil and water, rather than enhancing adhesion to foliage.