Let’s be honest.
When it comes to working out the application rate for boom spraying it’s easy to come unstuck.
And when we stuff it up it’s a costly exercise. For instance, if we put on 10% more chemical than we need, the chemical ends up costing us 10% more than we planned.
It’s actually quite simple to apply the right amount of product once you know what factors to consider.
3 questions to ask yourself when calculating your spray application rate
1. “What pressure is running through my pump?”
- Check the pressure gauge on your equipment (or call us if it’s not working!)
- Most boom sprayers are around 3.5 bar which is about 50psi
- Here’s a handy calculator if you need to switch beween PSI and Bar
2. “What colour (size) nozzles am I using?”
- Nozzle size (and therefore flow-rate) is normally identified by nozzle colour
- Most farmers use blue (#03), red (#04) or brown (#05) for general spraying
- The examples below for boom spraying are the latest and greatest nozzles from AIXR TeeJet (these are great if your existing nozzles are a little tired)
3. “How fast will I be driving?”
- Level farms are suited to speeds of around 8-10 km/h, whereas hill country is normally more like 4 km/h
- More important than the speed itself is the consistency of speed (to ensure even application)
So What’s Next?
With a handle on the above 3 things, use the chart below to find your desired application rate.
For example, if your product calls for 200 litres per hectare, here are two of the many options available:
- 3 Bar pressure, Red (#04) nozzle, 9kph or
- 1 Bar pressure, Blue (#03) nozzle, 4kph
Do you have your own application rate question? Leave a comment below, or call me (Mike) on 07 847-7811.