Importance of calibration and getting sprayer rates correct
Spraying application doesn’t work as well as expected too often and the most likely reasons for this is incorrect calibration and incorrect application rates. You need to ensure that you are putting the right amount of pesticide onto the treated area with accurate, effective application through proper calibration.
Calibrating your sprayer should be done regularly as part of your operational maintenance and not just when it doesn’t work or produce the results you want. General equipment wear with the nozzle and pump can result in changes over time with sprayer output. Before you start calibration, you need to check your sprayer is fully working, not leaking, clogged or broken in any way. Also check you have the correct nozzles fitted on to the sprayer.
As much as you may hate maths, there is some simple maths involved in the calculations for calibration. These are different depending on the equipment you are using and your preferred calibration method. For pull-behind or self-propelled sprayers you need to determine nozzle output, forward speed and application width; and then use these to determine how much pesticide needs to be added to the spray tank to achieve the correct rate for the results you want. Check the product label for the correct rates or speak to a BASIS qualified adviser to help.
There are many different weights and volumes used when working out what area you have, or how much product you may require. All pesticide dosage rates are given in metric units.
There must be consistency between calibration and actual application, to spray pesticides in a cost-effective manner. If you calibrate your sprayer at a certain speed or pressure, then make sure you use the same speed and pressure when you apply the pesticide!
Our Calibration Tips:
- Experts recommend using a half-full tank when calibrating as constant speed and pressure are important for proper calibration.
- Inclines, declines or uneven ground can skew the calibration so make sure you perform your calibration run on even, level ground.
- Add a dye such as Blue-gem to the water to help you see spray patterns more easily.
- Mark the start and end of the run with a line and ensure your sprayer is up to speed when you cross the start line and continuing at the same speed past the finish line. Turn nozzles on and off as you pass the lines.
- Remember to re-calibrate if you change any variations in the ‘calibration equation’ for example changing sprayer pressure, nozzles etc.
