Check the accuracy of your sprayer periodically to make sure you are applying the amount recommended on the pesticide label (Fig. 1). Guidelines established by the U.S Department of Agriculture and the Environmental Protection Agency indicate that the difference between a sprayers actual application rate and intended application rate should not exceed 5 percent of the intended rate. However, surveys conducted in Ohio and other states indicate that only one out of four sprayers are applying chemicals with application errors less than 5 percent. Calibrating a sprayer is not difficult, and detailed information is available from your local county Extension office.
Calibrate your sprayer to determine the actual application rate.