To double nozzle flow rate, pressure must increase four times.

Pressure cannot be used to make major changes in rate, only minor changes due to nozzle wear and other factors.

Doubling the ground speed of a sprayer reduces the gallons per acre (GPA) by half.

Doubling the effective spray width per nozzle decreases the GPA by one-half.

GPA = gallons per acre

GPM = gallons per minute

OPM = ounces per minute

MPH = miles per hour

W = nozzle spacing in inches (broadcast spraying)
= band width in inches (band spraying)

Some pesticides may be sold in formulations that contain different amounts of the same active ingredient. Therefore, manufacturers may give the rate in terms of active ingredient (a.i.) per acre or 1000 feet of row. To determine the application rate of actual formulated product, use the following formulas:

For dry products:

For Liquid Products:

Note: If interested in determining rates in terms of lb or gal per 1000 feet of row, replace acre in equations above with 1000 feet of row.