Calibrating Nozzles

Frequency of Calibration

Even though a sprayer’s operation can be theoretically determined using mathematical formulas, there are still many reasons to verify that the output is what it should be. For example,

• wear (especially on nozzles)
• damaged or malfunctioning parts (such as pressure gauges)
• plugged or restricted passages (such as strainers and hoses)

Obviously, pre-season visual checks are not adequate for accurate application, nor is the fact that equipment and nozzle tips are new. Also, manufacturer’s catalogs are only guidelines; fine-tuning a sprayer is the operator’s responsibility.

A sprayer’s output should be checked:

• after any adjustments
• when switching to a new chemical or application rate
• after a week of continuous use under the same circumstances

Verifying the results of an adjustment is standard procedure for all John Deere products. Never make adjustments to a sprayer without then verifying the output from the nozzles.

Cost	Resulting In:
Wasted Resources	Over-or-under-application of expensive chemicals
Reduced Yield/Quality	Chemical stress, pest pressure remaining
Effect on Future Crops	Chemical carryover