If you double the ground speed without changing other factors, what happens to the spray per acre?

• A. It doubles.
• B. It remains the same.
• C. It increases by 50%.
• D. It is reduced by about one-half.

Answer: (D)

Spray application rate is determined by how much liquid the sprayer puts out per minute and how fast you move across the field. With all other factors held constant, the amount sprayed per unit area changes inversely with ground speed. If you double the ground speed, you cover more area in the same amount of time, so the spray per acre becomes about half as much. To keep the same rate per acre at the higher speed, you’d need to increase the nozzle flow proportionally.