In spray technology, the function of a sticker adjuvant is to:

• A. Increase viscosity
• B. Improve drift
• C. Decrease surface tension
• D. Increase evaporation rate

Answer: (A)

Sticker adjuvants are used to make pesticide deposits stay on leaf surfaces longer by forming a sticky film, which often comes from increasing the viscosity of the spray. That higher viscosity helps droplets remain attached rather than running off or being washed away, so more of the active ingredient stays in contact with the plant.

Other properties mentioned aren’t the primary role of stickers—lowering surface tension is the job of surfactants to improve wetting and spread, improving drift would be undesirable and isn’t the purpose of stickers, and increasing evaporation rate would reduce how long the pesticide remains active on the surface.