In the GPA calculation, which statement correctly reflects how GPA is determined?

• A. Speed mph is used with GPM and swath width to determine GPA
• B. Temperature is used with GPM and swath width to determine GPA
• C. Humidity is used with GPM and swath width to determine GPA
• D. Field yield is used with GPM and swath width to determine GPA

Answer: (A)

GPA represents gallons per acre, and it’s determined by how much spray the equipment delivers per minute relative to how much area you cover per minute. The speed you’re traveling (in mph) sets how quickly you move across the field, and the swath width tells how wide a strip you’re spraying with each pass. When you combine the flow rate (GPM) with those two factors, you get the gallons per acre sprayed. Temperature, humidity, or field yield don’t change this basic calculation; they can influence spray performance and deposition, but not the arithmetic for GPA. So using speed mph together with GPM and swath width to determine GPA is the correct approach.