Which factor causes spray to leave the target area?

• A. percolation
• B. inversion
• C. drift
• D. large spray droplets

Answer: (C)

Drift is the unintended horizontal movement of spray droplets away from the target area caused by air flow after the spray is released. This is the mechanism that makes spray leave the target area. Smaller, finer droplets are carried farther by wind and air currents, increasing drift, while larger droplets are heavier and settle faster, reducing off-target movement. Percolation describes liquid moving through soil, which isn’t about airborne spray, so it doesn’t explain off-target movement. An inversion, a weather condition with temperature layering, can affect air mixing and thus how far droplets travel, but the direct cause of spray leaving the target area is drift itself.