Sprayer Set-up

A clear understanding of how a sprayer operates and especially knowing the factors influencing the amount of liquid applied is essential in the proper set-up of a sprayer. Proper calibration of herbicide application equipment is essential for safe, economical and effective weed control. Disregarding proper set-up steps or using equipment which has not been regularly maintained can result in a costly loss of chemicals, damage to other crops or pastureland, or damage to the environment.

  • Plan ahead — Be certain to carefully read and fully understand the directions for calibrating applicator equipment written on the label of the herbicide product to be used.
  • The application equipment must be clean of other herbicides. This is especially iimportant if he equipment was used in appliying an herbicide that could be harmful to other crops, pastures or forages.
  • Use the correct application nozzles. Refer to the label directions, if in doubt.
  • Are the nozzles types appropriate for the herbicide being used?
    • all the same size? 
    • spaced evenly?
    • clean?
    • in good repair?
    • equipped with the correct screen mesh size?
  • Check and fix any problems such as leaks and values that are not working properly.
  • Adjust the pressure regulator to get the right spray pressure at the nozzles.

Maintaining a nozzle tip height of 24 inches above the crop canopy encourages the maximum spray coverage and reduces the potential for off-target drift.  Follow equipment manufacturer’s instructions and product labels to ensure the best weed control.

“A Simple Method to Calibrate Sprayers” This publication by the UT Beef and Forage Center will help you calibrate both a boom and boomless sprayer correctly.
Before you can accurately apply the right amount of herbicide to a field, you have to know how much spray mix is being applied to each acre. This knowledge will help you determine how many acres you can cover with one tank and how much herbicide to add to each tank. Sprayer calibration is not difficult, but it can be challenging if you have never seen it done before. 

  • Always start your planned herbicide application with clean application equipment.
  • Immediately following the herbicide application, thoroughly flush the tank and rinse the spray equipment three times (3x) with an ammonia-based compound to protect against any herbicide residue settling in the tank or in any of the spray components.
  • Do NOT allow the spray solution to remain in the spray boom lines overnight prior to flushing.
  • Wash all parts of the of the tank, including the inside top surface. 
  • Flush hoses, spray lines and nozzles for at least 1 minute with the cleaning solution.
  • Remove nozzles, screens, and strainers and clean separately in the cleaning solution if necessary to remove all residue.
  • Rinse the complete spraying system with clean water.
  • Clean and wash the outside of the entire sprayer and boom. 
  • Rinse all sprayer equipment to prevent seed contamination. Weed seeds can be spread inadvertently to non-contaminated fields, if the equipment has not been properly cleaned of weed seeds.