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START
Spray
Orchard sprayer calibration
UseUse water only water only
when calibrating when calibrating the sprayerthe sprayer
CHECK sprayer
and mend
Adjust SPRAY VOLUME if required
Calculate SPRAY
VOLUME
Adjust sprayer to the CROP
PrepareTANK-
MIX
1
Measure tractor SPEED
Picture source: Syngenta
Measure FLOW-RATE
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Estacas
Nozzle brush
Knife
Calibration Materials
Poles
Measuring jug 2 L
Calculator
Stopwatch
Measuring tape 20-50 mHoses 30 cm(as many as calibrated nozzles)
Logbook
2
Water sensitive paper & stapler
Flagging-tape Roll measure 2-3 m
Orchard sprayer calibration
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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
3
Orchard sprayer calibration
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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)
Before calibration
4
Orchard sprayer calibration
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Measure the tractor speed
1) Mark a test strip of e.g. 100 m2) Fill tank about half with water3) Set tractor speed (gear, throttle at 540 rpm
on PTO) as for spraying4) Reach selected speed and engine rpm
before entering the test strip. Maintain constant speed and record time to travel 100 m
5) Measure time: _____ sec. (example: 45 sec.)
6) Calculate tractor speed
Distance100 m
Conversion Factor 3.6X
=
Time measured72 sec.
5.0 km/h
Measuring tape 20-50 m
Poles logbook
Stopwach
Calculator
5
Orchard sprayer calibration
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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.
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Orchard sprayer calibration
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7
Measuring jug 2 L
Stopwatch
Notebook
Calculator
Measurement of individual nozzle output during 1 min.
1) Choose same engine rpm as used in speed measurement2) Open valve(s) to start spraying3) Collect the water from each nozzle (via hose on nozzle) during
1 minute in a measuring jug4) Record the water output from each nozzle 5) Calculate the average flow-rate per nozzle (L/min)
Hoses 30 cm(as many as nozzles to be calibrated)
Nozzle LEFT RIGHT
1 lowest
2
3
4
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
Orchard sprayer calibration
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
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Measurement of tank volume sprayed during 5 min.
Refilled amount80 L
Spraying time in minutes
5 min
1.6 L/minper nozzle
X
Open nozzles
10 pieces
=
1) Fill the spray tank with water up to a clearly defined level, e.g. the top level (including pump, etc.)
2) Leave tractor running throughout the calibration process
3) Spray for 5 min.; pressure and engine rpm settings as for spraying
4) Measure the volume to refill the sprayer to the defined level
5) Calculate the flow-rate per nozzle
Orchard sprayer calibration
Step 1-3: do not change the position
of the sprayer!
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SpraySprayVolumeVolumeper haper ha
Flow-rate1.6 L/min
Factor600
Open nozzles10 pieces
Row width4 m
Tractor speed5.0 km/h
480 L/ha
Calculate the Spray Volume (L/ha)
9
X X
X
=
Row width
Orchard sprayer calibration
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Recommended spray volumes (L/ha)
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If the calculated spray volume is within the recommended range of spray volumes, continue with ‘Adjustment of the sprayer to the crop’
crop width
Cro
p he
ight
row 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
Orchard sprayer calibration
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How to adjust spray volumes (L/ha)
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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. See calculation next slides
Adapt spray pressure (small adjustment): Small adjustments in flow rate can be made by adjusting the pressure See calculation next slides
Orchard sprayer calibration
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Change nozzle size (large adjustment)
1) Calculate the required flow-rate per nozzle based on the calibrated tractor speed and targeted spray volume
2) Select appropriate nozzle size / colour, e.g. GREY for 2.0 L/min.
Speed5.0 km/h
Row Width4 m
X X Spray Volume600 L/ha
X
=Factor
600Open nozzles
10 pieces
2.0L/minper nozzle
Targeted spray volume
Measured Measured
Countedkm/h – L/min
Required flow-rate
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Orchard sprayer calibration
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Present tracor speed 5.0 km/h
X
Present spray volume 480 L/ha
Targeted spray volume600 L/ha
= New tractor speed 4.0 km/h
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)
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Orchard sprayer calibration
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Adapt spray pressure (small adjustment)
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Present pressure 5 bar x
Targeted spray volume600 L/ha
Present spray volume 480 L/ha
New Pressure6.25 bar=
2
Optimal pressure range
Flat fan and hollow cone nozzles: 5-10 bar (kg/cm2)Air-injector (Anti-drift, ID nozzles: 10-14 bar (kg/cm2)
Always stay within the optimal pressure range of nozzles. Changes in pressure can change the droplet size and may cause drift or run-off.
Orchard sprayer calibration
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Adjustment of blower performance to the cropOrchard sprayer calibration
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
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Calculation of blower performanceAir displacement required to fill the tree rows m3/h
during spraying (see picture)
Orchard sprayer calibration
xRow width 4 m
Height of leaf wall 3 m
=xTractor speed 5 km/hAir displacement factor 3
Factor 1,000 20,000 m3/h
Row width
m3/h
x
Air displacement factors tree crown large: 2 tree crown normal: 3 tree crown narrow: 4
Example
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above crop: should not move
1) Prepare two poles, at least 50 cm higher than the crop
2) Place poles in rows and fix flagging tapes at 4 levels:
a) 50 cm above cropb) At top of cropc) At bottom of cropd) 50 cm below crop
3) Place flagging tapes at upper and lower baffle
4) 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
Bottom of crop:movement
Below crop:should not move
Top of crop:movement
Flagging-tape
Poles
Adjustments of air stream to the crop
17
Orchard sprayer calibration
Roll measure 2-3 m
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Water sensitive paper & stapler
Dynamic spray-pattern and distribution test
18
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
Orchard sprayer calibration
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Calculation of how much pesticide to add to the spray tank
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Orchard sprayer calibration
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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
There are three possibilities how the product dose is indicated on the pesticide label:
Calculation of how much pesticide to add to the spray tank
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Prepare tank mix
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Label indication (product per ha)
3 L / haX
Volume of water in spray tank
800 L=
Spray volume per ha480 L /ha
5 L
product
MeasuredPesticide label Product in tank
Calibrated
Example:1) Pesticide label indication: use 3 L/ha product2) Sprayer tank content: 800 L of water; the calibrated spray volume of the sprayer is 480 L/ha3)With 800 L of water 1.67 ha can be treated (800 L / 480 L/ha = 1.67 ha)4)Product needed in the tank is: 3 L /ha product x 1.67 ha = 5.0 L
Label indication: Use xxx L/ha or g/ha
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Prepare tank mix
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Use rate300 g/100 L X
Volume of water in spray tank
800 L=
Spray volume per ha480 L /ha
5,000 gproduct
MeasuredPesticide label Product in tank
Calibrated
Conversion Factor100
Example:1)Pesticide label indication: use 300 g/100 L of water ..... Use spray volume of 1,000 L/ha2)Sprayer tank content: 800 L of water; calibrated spray volume per ha 480 L/ha3)If 1,000 L /ha are used then 300 g x 8= 2,400 g of product must be added to the tank4)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 2.08 = 5,000 g = 5 Kg
Label indication: Use xxx L or g /100 L water in a specific spray volume, e.g. 1,000 L of water /ha)
22
Prepare tank mix
Spray volume information1000 L/ha
Pesticide label
X
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Label indication: Use xxx L or g /10,000 m2 Leaf Wall Area (LWA)
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The LWA for a specific orchard is calculated as follows:
Prepare tank mix
Example:1) Pesticide label indication: use 3 L product per 10,000 m2 LWA (LWA per ha ground area)2) 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 LWA3) Sprayer tank content: 800 L of water; the calibrated spray volume of the sprayer is 480 L/ha (ground area)4) With 800 L of water 1.67 ha can be treated (800 L / 480 L/ha = 1.67 ha)5) Product needed in the tank is: 4.5 L /ha product x 1.67 ha = 7.50 L
x
Ground area 10,000 m2
Row width 4 m
Height of leaf wall 3 m =x Both sides of leaf
wall: Factor 2LWA
15,000 m2
Represents row length
per ha ground area
Measured crop (foliage) height