Which of the following is NOT a method to minimize the number of small particle droplets while still allowing sufficient coverage?

• A. Reduce sprayer pressure
• B. Use drift reducing nozzles
• C. Use thickening or drift control adjuvants
• D. Increase sprayer speed

Answer: (D)

The main idea here is controlling drift by managing droplet size while still getting enough spray on the target. Small droplets tend to drift off-target, so methods that help produce larger droplets or keep them from drifting are used to maintain coverage without increasing drift.

Reducing sprayer pressure lowers the energy of atomization, which makes bigger droplets. Bigger droplets are heavier and settle more readily onto the target, reducing drift while preserving coverage. Drift reducing nozzles are designed to produce coarser droplets and shape the spray in a way that limits off-target movement, again helping with deposition on the intended surface. Thickening or drift control adjuvants increase the viscosity or create conditions that promote droplet coalescence or retention, which also yields larger droplets and better deposition with less drift.

Increasing sprayer speed does not fit this pattern. It can alter the spray cloud in ways that don’t reliably reduce the small droplet fraction and may even raise drift potential or compromise uniform coverage.