Which factor is NOT listed as contributing to spray drift according to standard guidance?

• A. Air temperature
• B. Wind speed
• C. Droplet size
• D. Nozzle type

Answer: (D)

The main idea is understanding what factors influence how far and how droplets drift from a spray. Standard drift guidance focuses on environmental and droplet characteristics: wind speed, air temperature, and the size of the droplets produced. Wind speed directly pushes droplets off target, increasing drift. Droplet size is crucial because fine droplets stay in the air longer and travel farther than larger ones. Air temperature matters because it affects evaporation and air density, which can make droplets shrink midflight and drift more easily. Nozzle type, while it does affect what droplet sizes you produce, isn’t listed as a separate contributing factor in that guidance. Its influence on drift is indirect—through the droplet size distribution—rather than being named as an independent factor. So nozzle type isn’t cited as its own drift contributor, even though choosing nozzles that produce coarser droplets can help reduce drift.