Safe Use Initiative
Orchard sprayer calibration
START
CHECK
sprayer
and mend
Measure
tractor
SPEED
Measure
FLOWRATE
Calculate
SPRAY
VOLUME
Use
water only
when calibrating
the sprayer
Adjust SPRAY
VOLUME
if required
Spray
Prepare
TANK-MIX
Picture source: Syngenta
Adjust sprayer
to the
CROP
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Safe Use Initiative
Orchard sprayer calibration
Calibration Materials
Measuring tape 20-50 m
Measuring jug 2 L
Hoses 30 cm
(as many as calibrated nozzles)
Estacas
Poles
Stopwatch
Logbook
Flagging-tape
Nozzle brush
Knife
Roll measure
2-3 m
Calculator
Water sensitive paper &
stapler
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Safe Use Initiative
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




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Safe Use Initiative
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)
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Safe Use Initiative
Orchard sprayer calibration
Measure the tractor speed
Poles
logbook
Stopwach
Measuring tape 20-50 m
Calculator
1) Mark a test strip of e.g. 100 m
2) Fill tank about half with water
3) Set tractor speed (gear, throttle at 540 rpm
on PTO) as for spraying
4) 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
Distance
100 m
X
Conversion
Factor 3.6
=
5.0
km/h
Time measured
72 sec.
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Safe Use Initiative
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.
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Safe Use Initiative
Orchard sprayer calibration
Measurement of individual nozzle output during 1 min.
Notebook
Measuring jug 2 L
Hoses 30 cm
Stopwatch
(as many as nozzles
to be calibrated)
If required fix
hoses on
nozzles with
clamps or Orings
1) Choose same engine rpm as used in speed measurement
2) Open valve(s) to start spraying
3) Collect the water from each nozzle (via hose on nozzle) during
1 minute in a measuring jug
4) Record the water output from each nozzle
5) Calculate the average flow-rate per nozzle (L/min)
Calculator
Nozzle
LEFT
RIGHT
1 lowest
2
For
uniform flow rate,
3
variability between the
4
nozzles should be < +/5% from the average flow
4
rate
5
Nozzles
differing > +/- 5%
6
should be cleaned or
7
replaced and flow rates
8
checked again
9
10
Total I
Total II
L/ min all nozzle
L/min
L/ min per nozzle
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Safe Use Initiative
Orchard sprayer calibration
Measurement of tank volume sprayed during 5 min.
Step 1-3: do
not change
the position
of the
sprayer!
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
Refilled amount
80 L
=
Spraying time in
minutes
5 min
X
Open
nozzles
10 pieces
1.6 L/min
per nozzle
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Safe Use Initiative
Orchard sprayer calibration
Calculate the Spray Volume (L/ha)
Spray
Volume
per ha
Row width
Flow-rate
1.6 L/min
X
Factor
600
X
Open nozzles
10 pieces
=
Row width
4m
X
480 L/ha
Tractor speed
5.0 km/h
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Safe Use Initiative
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’
Recommended spray volumes
crop width
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
Follow pesticide label information
row width
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Safe Use Initiative
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.
 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
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Safe Use Initiative
Orchard sprayer calibration
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.
Speed
5.0 km/h
Targeted spray
volume
Measured
Measured
X
Row Width
4m
X
Required flow-rate
Spray Volume
600 L/ha
=
Factor
600
km/h – L/min
X
Open nozzles
10 pieces
2.0
L/min
per
nozzle
Counted
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Safe Use Initiative
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 tracor speed
5.0 km/h
Present spray volume
480 L/ha
X
=
Targeted spray volume
600 L/ha
New tractor speed
4.0 km/h
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Safe Use Initiative
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 runoff.
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)
2
Targeted spray volume
600 L/ha
Present pressure
5 bar
x
Present spray volume
480 L/ha
=
New Pressure
6.25 bar
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Safe Use Initiative
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
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Safe Use Initiative
Orchard sprayer calibration
Calculation of blower performance
Example
Row width
4m
Air displacement required to fill the tree rows m3/h
during spraying (see picture)
x
Height of leaf wall
3m
x
Tractor speed
5 km/h
x
Factor 1,000
=
20,000 m3/h
Air displacement factor 3
Row width
Height of leaf wall
Air displacement factors
 tree crown large: 2
 tree crown normal: 3
 tree crown narrow: 4
m3/h
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Safe Use Initiative
Orchard sprayer calibration
Adjustments of air stream to the crop
Roll measure
2-3 m
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)
b)
c)
d)
50 cm above crop
At top of crop
At bottom of crop
50 cm below crop
above crop:
should not move
Flaggingtape
Poles
Top of crop:
movement
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
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Safe Use Initiative
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
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Safe Use Initiative
Orchard sprayer calibration
Calculation of how much pesticide
to add to the spray tank
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Safe Use Initiative
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
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Safe Use Initiative
Prepare tank mix
Label indication: Use xxx L/ha or g/ha
Example:
1)
2)
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
3) 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
Measured
Pesticide label
Label indication
(product per ha)
3 L / ha
X
Product in tank
Volume of water in
spray tank
800 L
=
Calibrated
5L
product
Spray volume per ha
480 L /ha
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Safe Use Initiative
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:
1)
2)
3)
4)
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
2.08 = 5,000 g = 5 Kg
Pesticide label
Use rate
300 g/100 L
X
Measured
Pesticide label
Spray volume
information
1000 L/ha
X
Product in tank
Volume of water in
spray tank
800 L
=
Conversion Factor
100
Calibrated
Spray volume per ha
480 L /ha
5,000 g
product
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Safe Use Initiative
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
Represents
row length
per ha
ground area
(foliage) height
Ground area
10,000 m2
x
Row width
4m
Height of leaf
wall 3 m
x
Both sides of leaf
wall: Factor 2
=
LWA
15,000 m2
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
3) 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
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1)
2)