Anti-drift agent

Definition

A formulation additive or adjuvant that increases droplet size and reduces off-target movement of pesticide sprays, thereby improving deposition on target vegetation and minimizing exposure to adjacent habitats. These agents function by increasing spray viscosity, reducing evaporation, or promoting droplet coalescence, and are particularly important in aerial application and near-field edge habitats where beneficial and non-target arthropods are at risk.

Etymology

Example

When spraying Bacillus thuringiensis for gypsy moth control near a meadow supporting native bee populations, an anti-drift agent such as a vegetable oil-based extender is added to the tank mix to suppress fine droplets that would otherwise carry the bacterial toxin onto flowering plants.

Synonyms

• drift retardant
• deposition aid

Related Terms

• adjuvant
• Formulation
• Integrated Pest Management
• non-target effects
• Buffer zone
• aerial application

Usage Notes

Distinguished from surfactants or spreaders, which primarily affect droplet spread on the leaf surface rather than transport behavior in air. The term is used prescriptively in regulatory contexts (e.g., EPA drift reduction technology ratings) and descriptively in field protocols. Effectiveness varies with nozzle type, wind speed, and temperature; anti-drift agents are often mandatory in applications near sensitive habitats for pollinators or beneficial predatory arthropods.