Calibration is very important in aerial application because:

• A. Chemicals used for aerial application are much more toxic
• B. Vortices can change application rates
• C. Large areas are covered in a short time
• D. Much higher pressures are used during aerial application

Answer: (B)

Calibration is essential because the air turbulence created by the aircraft—the downwash and vortices—can cause the spray droplets to be deposited unevenly, changing the actual rate at which the chemical reaches the target. By calibrating, you determine the real output of the nozzle system under expected flight conditions (speed, altitude, nozzle type, droplet size) and adjust your settings so the labeled rate is applied consistently across the swath. This ensures effective pest control while avoiding under- or over-application, despite the turbulent air patterns around the aircraft. The other statements don’t capture why calibration matters: the chemical’s toxicity is a safety concern, but not the reason calibration is needed; the speed of covering large areas is about efficiency, not rate accuracy; and higher pressures aren’t the core factor driving the need for calibration.