Spring Sprayer Prep: Essential Maintenance and Calibration

With Spring here and crop stands beginning to grow, it is time to shift focus to the next operation of the 2026 growing season: spraying. These operations are "make or break" for crop health, whether you are applying weed control, warding off insects, or managing bacteria and fungus. While these operations require financial and time investments, performing proper maintenance and calibrations directly impacts success rates and your ultimate return on investment.

Farmers should pay attention to pesticide labels and alway read the most current version as there may be changes related to the Environmental Protection Agencies (EPA) Endangered Species Act. Meaghan Anderson, covers this topic in depth and provides great resources surrounding this subject in a previous ICM blog post, "Prepare now for 2026 EPA Endangered Species Requirements". 

Safety Note: Anyone involved in these preparations must understand the potential hazards of working on these systems. Always wear proper personal protective equipment (PPE) and choose a safe location for any maintenance and calibrations.

Phase I: Physical Inspection & Maintenance

Begin with a physical inspection of all components that move liquid from the tank to the nozzle tips, including but not limited to hoses, O-rings, fittings, and motors.

• Tank & Boom/hose inspections: Inspect the tank for debris, buildup, or cracks. Check the functionality of boom breakaway sections and ensure the boom is level. While checking the boom, make sure to check all hoses are free from any dry rotting, wear points, and holes
• Filters: Inspect and clean both the main line strainers and individual nozzle screens. Clearing debris here is essential for successful calibration later.
• Nozzle tips: When is the last time you replaced your tips? The orifice can wear over time, changing the spray pattern, droplet size, and application rate. These should be checked a couple times per season and replaced with regular use.
• Moving Parts: Check on-board motors, pumps, and flow meters. Verify oil levels where applicable and ensure components are free spinning before an active system test. Listen for unusual noises, which are clear indicators of mechanical issues.
• Feedback Systems: Verify pressure sensors, section control, and nozzle bodies. Checking solenoids or air-actuated valves ensures systems fire correctly and prevents chemical dripping once closed.

Phase II: The Calibration Process

To calibrate your sprayer, first define your target gallons per acre (GPA), operation speed (MPH), and operating pressure (PSI). Proper calibrations and effective applications require balancing these parameters to achieve the droplet spectrum often dictated by the product label.

This leads directly into nozzle selection; a nozzle's core function is to atomize the spray solution into a specific droplet spectrum. Applicators must understand the required droplet size for the operation by consulting the specific chemical label. Additionally understanding that coverage and drift management are a balancing act. So, selecting the correct nozzle, given your spraying parameters is very important. A good example can be seen in the labels for chemistries of Dicamba HD® and Enlist One™, which specify to select a nozzle that provides coarser droplets as to reduce the drift potential of that application. 

Note: That it is important to read the specific label for the product you are applying. Dicamba products approved for use in soybeans will have different requirements including but not limited to temperature limits and label-approved nozzles. 

Dicamba HD®:

• “Ground: Use coarse sprays to avoid potential herbicide drift. Select nozzles that are designed to produce minimal amounts of fine spray particles (less than 200 microns). Examples of nozzles designed to produce coarse sprays via ground applications are Delavan® Raindrops, Spraying Systems XR (excluding 110° tips) flat fans, Turbo Teejets®, Turbo Floodjets®, or large capacity flood nozzles including D10, TK10, or greater capacity tips.”
• “Aerial: Select nozzles designed to produce minimal amounts of fine spray particles. Make aerial applications at the lowest safe height to reduce exposing the spray to evaporation and wind.”

Enlist One™:

• Recommends the usage of the large droplets as to reduce spray drift and have a published list of allowable manufacturers, nozzle types, and pressure ranges for applications (Figure 1).

Figure 1. Graphic illustration from Corteva Agriscience on the qualified combinations of nozzle selections and acceptable pressure ranges for proper drift management. (Enlist One Allowable Nozzles | Enlist™ weed control system)

*Disclaimer: The label is the law. Prior to any pesticide application, always read and fully understand the product label, including its specific requirements for your target cropping system, application situation, and environmental conditions. *

Now that you have thought through your target spraying parameters and nozzle selection the next step is to perform the calibration. For the procedure for the Catch Test Sprayer Calibration make sure to go read the past ICM blog "Is Your Sprayer Calibrated and Ready for Spring?"

Testing and calculations You can perform a manual catch test or use tools like a SpotOn® to quickly determine individual nozzle flow rates in gallons per minute (GPM). Use the standard 5940 equation to convert between GPA and GPM based on your speed and nozzle spacing.

To calculate GPA: 

GPA  = (5940 x GPM) / (MPH x Spacing)
 

To calculate GPM (per nozzle):

GPM = (GPA x MPH x Spacing) / 5940
 

An example of using this equation can be seen below: 

Nozzle spacing = 15 inches

Measured flow = 0.45 GPM

Travel speed = 12 MPH

Calculating GPA
GPA = (5940 × 0.45) ÷ (12 × 15) = 14.85 ≈ 15 GPA

Phase III: Advanced Tech Readiness

Technology readiness is now an essential part of modern farming.

• GPS Systems: Check receivers for damage prior to the season. These allow for essential functions like coverage maps, prescriptions, and auto-guidance.
• Software: Perform software and firmware updates pre-season to avoid waiting at the edge of the field. This also allows you to familiarize yourself with any new workflows.
• Data Organization: Ensure platforms like JD Ops Center, Case IH FieldOps, or Climate FieldView are organized. Update boundaries, delete unused versions, and clean up guidance lines using a clear nomenclature (e.g., Year_Operation_Direction).

Summary & Conclusion

While it requires an investment of time, staying compliant with licensing and continuing education ensures you can legally and safely apply pesticides. Remember that Iowa law requires keeping application records for at least three years. Also making sure you are compliant with chemical labels and state specific/federal legislation is your duty as a licensed applicator. 

Taking the time now to perform necessary maintenance, thorough calibration, and technology updates, will allow you to pull into your fields confidently this season.