Which steps are involved in calibrating a granular pesticide spreader for uniform coverage?

• A. Determine target rate per acre; measure conveyor/agitator output; adjust spread rate and front/back speeds; test on a known area.
• B. Fill the hopper and spray until the area looks covered.
• C. Set the spreader to the maximum setting and ignore testing.
• D. Calibrate by trial and error without a known area.

Answer: (A)

Calibrating a granular spreader for uniform coverage starts with setting a concrete application rate per area and then verifying it across the field. First, determine the target rate per acre so you know exactly how much product should be deposited on each acre of treated ground. This anchors everything to a measurable goal tied to the label and the crop needs. Next, measure the conveyor or agitator output to know how much material is actually being released over time. Without knowing the rate at which material leaves the hopper, you can’t reliably translate the target per-acre rate into settings for the spreader and the speed of travel. Then adjust the spread rate and the forward/backward speeds so that the amount delivered matches the target rate across the spread width as you move. Getting these pieces aligned—dispensed amount and movement speed—ensures uniform coverage rather than patches or gaps. Finally, test the calibration on a known area to confirm the actual rate and distribution; this validation step lets you fine-tune if needed and provides confidence before treating larger areas.

Visual inspection alone or applying to the whole field without measurements isn’t reliable for uniformity, and calibrating by trial and error without a known area doesn’t give you a verifiable, repeatable rate.