1. when calibrating the sprayer
19/04/2017
Orchard sprayer calibration
CHECK sprayer and mend
Measure tractor SPEED
START
Measure FLOW-RATE
Calculate
SPRAY VOLUME
Use
water only
when calibrating the sprayer
Adjust SPRAY VOLUME
if required
Spray
Adjust sprayer
to the
CROP
Prepare
TANK-MIX
Picture source: Syngenta 1
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2. Orchard sprayer calibration
Calibration Materials
Estacas
Poles
Measuring tape m
Measuring jug 2 L
Hoses 30 cm
(as many as calibrated nozzles)
Logbook
Calculator
Stopwatch
Nozzle brush
Water sensitive paper & stapler
Knife
Flagging-tape
Roll measure 2-3 m

3. Orchard sprayer calibration
Before calibration
CHECK sprayer and mend
Tank size (maximum volume of spray mixture) _______L
Hoses in good conditions 
Nozzles
Symmetrical on left and right sides 
All the same size 
All the same type 
Clean nozzles and filters 

4. Orchard sprayer calibration
Before calibration
Check with water (fill half tank with clean water)
Start sprayer pump and run tractor throttle at 540 rpm (PTO) 
Open valve to fill tubing and start spraying 
Clean nozzles (filters) producing distorted patterns 
Closed nozzles shall not drip 
Replace damaged nozzles 
Check and fix
Leaks 
Valves working properly 
Agitation working 
Read pressure at pressure gauge bar (kg/cm2)

5. Orchard sprayer calibration
19/04/2017
Orchard sprayer calibration
Measure the tractor speed
Stopwach
logbook
Poles
Measuring tape m
Calculator
Mark a test strip of e.g. 100 m
Fill tank about half with water
Set tractor speed (gear, throttle at 540 rpm on PTO) as for spraying
Reach selected speed and engine rpm before entering the test strip. Maintain constant speed and record time to travel 100 m
Measure time: _____ sec. (example: 45 sec.)
Calculate tractor speed
Distance
100 m
Conversion Factor 3.6 = X
5.0 km/h
Time measured
72 sec. 5
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6. Orchard sprayer calibration
Calibrate the flow-rate
There are two methods to determine the nozzles flow-rate:
Precise method: Measurement of individual nozzle output during 1 min.
Good estimation: Measurement of tank volume sprayed during 5 min.

7. Orchard sprayer calibration
Measurement of individual nozzle output during 1 min.
Stopwatch
Calculator
Notebook
Measuring jug 2 L
Hoses 30 cm
(as many as nozzles to be calibrated)
Nozzle
LEFT
RIGHT
1 lowest 2 3 4 5 6 7 8 9 10
Total I
Total II
L/ min all nozzle
L/min
L/ min per nozzle
If required fix hoses on nozzles with clamps or O-rings
For uniform flow rate, variability between the nozzles should be < +/- 5% from the average flow rate
Nozzles differing > +/- 5% should be cleaned or replaced and flow rates checked again
Choose same engine rpm as used in speed measurement
Open valve(s) to start spraying
Collect the water from each nozzle (via hose on nozzle) during 1 minute in a measuring jug
Record the water output from each nozzle
Calculate the average flow-rate per nozzle (L/min)

8. Spraying time in minutes
Orchard sprayer calibration
Measurement of tank volume sprayed during 5 min.
Step 1-3: do not change the position of the sprayer!
Fill the spray tank with water up to a clearly defined level, e.g. the top level (including pump, etc.)
Leave tractor running throughout the calibration process
Spray for 5 min.; pressure and engine rpm settings as for spraying
Measure the volume to refill the sprayer to the defined level
Calculate the flow-rate per nozzle
Refilled amount
80 L
1.6 L/min
per nozzle =
Spraying time in minutes
5 min
Open nozzles
10 pieces X

9. Orchard sprayer calibration
19/04/2017
Orchard sprayer calibration
Calculate the Spray Volume (L/ha)
Spray
Volume
per ha
Row width
Flow-rate
1.6 L/min
Factor
600
Open nozzles
10 pieces X X
480 L/ha =
Row width
4 m
Tractor speed
5.0 km/h X 9
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10. Orchard sprayer calibration
Recommended spray volumes (L/ha)
If the calculated spray volume is within the recommended range of spray volumes, continue with ‘Adjustment of the sprayer to the crop’
crop width
Recommended spray volumes
Follow pesticide label information
Indicative spray volume for tractor mist blower: 200-1,000 L/ha
Avoid run-off
There are models which take the row width and crop height, but also the crop width into consideration
Crop height
row width

11. Orchard sprayer calibration
How to adjust spray volumes (L/ha)
Change nozzle size (large adjustment):
For large adjustments, change nozzle size (check nozzle manufacturers catalogue)
See calculation next slides
Adapt tractor speed (medium adjustment):
Application volumes can be adjusted by altering the tractor speed.
Adapt spray pressure (small adjustment):
Small adjustments in flow rate can be made by adjusting the pressure

12. Orchard sprayer calibration
Change nozzle size (large adjustment)
Calculate the required flow-rate per nozzle based on the calibrated tractor speed and targeted spray volume
Select appropriate nozzle size / colour, e.g. GREY for 2.0 L/min.
Measured
Measured
Targeted spray volume
Required flow-rate X X =
Speed
5.0 km/h
Row Width
4 m
Spray Volume
600 L/ha
2.0
L/min
per nozzle
Factor
600 X
Open nozzles
10 pieces
km/h – L/min
Counted

13. Present spray volume 480 L/ha
Orchard sprayer calibration
Adapt tractor speed (medium adjustment)
Slower speeds increase the spray volume (L/ha) and faster speeds reduce it (prerequisite : the distance between the crop rows is the same)
Present spray volume 480 L/ha
Present tracor speed
5.0 km/h X
New tractor speed
4.0 km/h =
Targeted spray volume
600 L/ha

14. Orchard sprayer calibration
19/04/2017
Orchard sprayer calibration
Adapt spray pressure (small adjustment)
Always stay within the optimal pressure range of nozzles. Changes in pressure can change the droplet size and may cause drift or run-off.
Optimal pressure range
Flat fan and hollow cone nozzles: 5-10 bar (kg/cm2)
Air-injector (Anti-drift, ID nozzles: bar (kg/cm2) 2
Targeted spray volume
600 L/ha
New Pressure
6.25 bar
Present pressure 5 bar x =
Present spray volume
480 L/ha 14
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15. Orchard sprayer calibration
Adjustment of blower performance to the crop
Blower performance (m3/h) and tractor speed need to be adapted to the orchard in such a way that the spray mist just leaves the back of the trees
Blower performance too high: bad collection of spray by leaves/fruits, drift
Blower performance too low: spray deposit in the inner part of the trees insufficient

16. Air displacement factor 3
Orchard sprayer calibration
Calculation of blower performance
Air displacement required to fill the tree rows m3/h during spraying (see picture)
Example
Row width
4 m x
Height of leaf wall
3 m
Tractor speed
5 km/h
Factor 1,000
20,000 m3/h x x =
Air displacement factor 3
Row width
Air displacement factors
tree crown large: 2
tree crown normal: 3
tree crown narrow: 4
Height of leaf wall
m3/h

17. Orchard sprayer calibration
19/04/2017
Orchard sprayer calibration
Adjustments of air stream to the crop
Poles
Prepare two poles, at least 50 cm higher than the crop
Place poles in rows and fix flagging tapes at 4 levels:
50 cm above crop
At top of crop
At bottom of crop
50 cm below crop
Place flagging tapes at upper and lower baffle
Adjust the air-flow with baffles so that the tapes on the top and bottom of the crop are moving, and the ones 50 cm above and below the crop do not move
Roll measure 2-3 m
Flagging-tape
above crop: should not move
Top of crop:
movement
Bottom of crop:
movement
Below crop:
should not move 17
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18. Orchard sprayer calibration
19/04/2017
Orchard sprayer calibration
Dynamic spray-pattern and distribution test
Water sensitive paper & stapler
Staple water-sensitive paper onto a wooden lath and place the lath vertically in the crop rows
Water sensitive papers can also be stapled on leaves within the crop
Adapt nozzle setting if required, e.g. close top and/or bottom nozzles 18
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19. Orchard sprayer calibration
Calculation of how much pesticide to add to the spray tank

20. Calculation of how much pesticide to add to the spray tank
Prepare tank mix
Calculation of how much pesticide to add to the spray tank
There are three possibilities how the product dose is indicated on the pesticide label:
Label indication: Use xxx L/ha or g/ha
Label indication: Use xxx L or g /100 L water in a specific spray volume, e.g. 1,000 L of water /ha
Label indication: Use xxx L or g /10,000 m2 ‘Leaf Wall Area’ per ha ground area

21. Label indication (product per ha) Volume of water in spray tank
Prepare tank mix
Label indication: Use xxx L/ha or g/ha
Example:
Pesticide label indication: use 3 L/ha product
Sprayer tank content: 800 L of water; the calibrated spray volume of the sprayer is 480 L/ha
With 800 L of water 1.67 ha can be treated (800 L / 480 L/ha = 1.67 ha)
Product needed in the tank is: 3 L /ha product x 1.67 ha = 5.0 L
Pesticide label
Measured
Product in tank
Label indication (product per ha)
3 L / ha X
Volume of water in spray tank
800 L
5 L
product =
Spray volume per ha
480 L /ha
Calibrated

22. Spray volume information Volume of water in spray tank
Prepare tank mix
Label indication: Use xxx L or g /100 L water in a specific spray volume, e.g. 1,000 L of water /ha)
Example:
Pesticide label indication: use 300 g/100 L of water Use spray volume of 1,000 L/ha
Sprayer tank content: 800 L of water; calibrated spray volume per ha 480 L/ha
If 1,000 L /ha are used then 300 g x 8= 2,400 g of product must be added to the tank
If 480 L/ha are applied then the concentration needs to be 2.08 times higher, i.e. 1,000 L/ha / 480 L/ha = 2.08). (This because the same amount per cm² needs to be on leaves / fruits independent whether 480 L/ha or 1000 L/ha are applied). Product in sprayer tank = 2400g x = 5,000 g = 5 Kg
Pesticide label
Pesticide label
Measured
Product in tank
Use rate
300 g/100 L
Spray volume information
1000 L/ha
Volume of water in spray tank
800 L X X
5,000 g
product =
Conversion Factor
100
Spray volume per ha
480 L /ha
Calibrated

23. Both sides of leaf wall: Factor 2
Prepare tank mix
Label indication: Use xxx L or g /10,000 m2 Leaf Wall Area (LWA)
The LWA for a specific orchard is calculated as follows:
Measured crop (foliage) height x
Ground area 10,000 m2
Row width
4 m
Height of leaf wall 3 m =
Both sides of leaf wall: Factor 2
LWA
15,000 m2
Represents row length per ha ground area
Example:
Pesticide label indication: use 3 L product per 10,000 m2 LWA (LWA per ha ground area)
When the LWA for our specific orchard is 15,000 m2, then 15,000 m2 / 10,000 m2 = 1.5 times more product is needed, i.e. 3 L x 1.5 = 4.5 L for 15,000 m2 LWA
Sprayer tank content: 800 L of water; the calibrated spray volume of the sprayer is 480 L/ha (ground area)
With 800 L of water 1.67 ha can be treated (800 L / 480 L/ha = 1.67 ha)
Product needed in the tank is: 4.5 L /ha product x 1.67 ha = 7.50 L