Which technique would help minimize off-target drift?

• A. Spraying during a temperature inversion.
• B. Using the largest droplet particle to provide necessary coverage.
• C. Increasing the height of the nozzle above the target.
• D. Spraying only during calm, stable conditions.

Answer: (B)

Drift is driven largely by droplet size: smaller droplets are light and easily carried by air, while larger droplets are heavier and settle to the ground more quickly. Using the largest droplet size that still provides the required pest control means the spray has more mass and higher settling velocity, making it far less likely to be transported off target by wind or minor air currents. This directly reduces off-target deposition without sacrificing the needed coverage on the target area, especially when nozzle type and pressure are chosen to produce coarse to very coarse droplets.

Other approaches can still influence drift but are less reliably protective. Spraying during a temperature inversion can trap droplets in still air and cause unpredictable movement, increasing off-target drift. Increasing the height of the nozzle gives droplets more opportunity to travel before reaching the target. While spraying in calm, stable conditions helps, it depends on weather and isn’t a technique you can implement as reliably or consistently as selecting appropriately sized droplets.