Accurate sprayer calibration is essential to know what volume of spray is being applied. Calibration is a straightforward process that, once established as a routine, takes just a few minutes and can make a significant difference to accuracy and results.
Calibration is a three stage process:
• Establish the accurate forward speed used when spraying
• Identify the output per nozzle
• Calculate the application rate per hectare
Check sprayer speed
Check nozzle output
Check nozzle output at least twice a year, and ideally each month during busy spraying periods. Once nozzles start to wear, output rates can change very quickly and spread pattern will be affected. Firstly check for visible signs of damage.Refer to the manufacturers' nozzleoutput chart to establish expected flow rate,then measure output from each nozzle.
ACCURACY CHECK - Some trace element and liquid fertilizer formulations used in turf applications are particularly abrasive and can lead to high rates of nozzle wear. Check nozzles more regularly when using these products.
Calculate application rate
With the knowledge of the forward speed of the sprayer and the output from nozzles, the volume of spray being applied per hectare can be calculated:
Nozzle output (l/min) x 600 ÷ forward speed (km/h) ÷ nozzle spacing (m) = spray volume (l/ha)
Spray volume output can be adjusted by:
• Changing the forward speed
• Altering the operating pressure
• Changing to different sized nozzles
Use the free on-line Sprayer Set-up Calculator tools in the Syngenta GreenCast Application Zone website to see what changes are required to deliver any required water volume.
Case study calculation
To apply a water volume of 300 l/ha, using a sprayer with 0.5m nozzle spacing and operating at five kmh, for example, the GreenCast calculator shows that you require a nozzle output of 1.25 l/min.
If any changes to required deliver a specific water volume are outside the realistic operation of a particular nozzle size, it will be necessary to change the nozzles to a smaller or larger size orifice.
For most turf applications applying foliar treatments on greens or fairways at 250 to 350 l/ ha - typically at four to seven kmh - a set of .025 and 04 nozzle will be most appropriate to cover the range. For soil target treatments requiring higher water volume, such as wetting agent or Fairy Ring fungicides, an 08 nozzle will apply a 500 - 700 l/ha at six to seven kmh.
| • Calibrate sprayers regularly, especially during busy periods |
• Inspect sprayers for leaks or damage during calibration | |
• Record results of nozzle set calibration and sprayer settings | |
• Replace the whole set of nozzles if any are worn | |
• Use a Syngenta Calibration Checker for quick results | |
• Check nozzle height is 50cm |
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