Farmers' guide on choice and safe use of pesticide application equipment

1. Pesticide Application Equipment
and Safety
Prepared by Aggrey Atuhaire
atuagrey3@gmail.com , +256-779864929

2. Pesticide application equipment
(examples)
lever-operated sprayers compression sprayers

3. Equipment examples….
Motorised sprayer Handheld sprayer

4. Lever-operated knapsack (LK)sprayer

5. WHAT SHOULD WE CONSIDER WHEN
BUYING AN LK SPRAYER?

6. BUYING LK knapsack sprayer
Handle for carrying
Easy re-fit of straps
Non-absorbent material
Grip for final adjustment of straps

7. BUYING LK knapsack sprayer
Air vent lid
-Possible to shift lever to other
side of tank
-Access to shift broken
diaphragm
-Drainage holes in base

8. BUYING LK knapsack sprayer
Strainer for filling  -IN-line strainer 
-Easy access for strainer cleaning 

9. BUYING LK knapsack sprayer
Possible to set for high or low maximum
Pressure / pressure relief valve
Standard cone nozzle and seal – plus
different nozzle types
Wide range of nozzles can be fitted in nozzle holder

10. BUYING LK knapsack sprayer
Possible to lock in off (and on) position
In line strainer – fixed to hose

11. BUYING LK knapsack sprayer
Possible to read tank contents?

12. BUYING LK knapsack sprayer
Easy splash-free water filling  Leaking from lid and pump !

13. Operator Safety and Environmental
requirements
(what do international standards say?)

14. Examples of safety hazards for
knapsack sprayers
• Getting fingers caught between lever and
frame
• Cuts from sprayer parts
• Strain by heavy lift
• Injury by bursting parts
• Dermal contact, oral intake and inhalation of
spray droplets or vapour
• Tenseness, bad posture, premature tiredness

15. Sources of environmental hazards for
knapsack sprayers
• Leakages
• Controls
• Filling and emptying
• Application rates
• Distribution, deposition and drift
• Loss during stoppage
• Cleaning

16. ISO 19932 (2013) Safety and
Environmental requirements
• GENERAL
- all functions possible for operator wearing
protective gloves
- not heavier than 25 kg
- materials chemical resistant
- avoid outside accumulation of liquid (max. 70 ml)
- resistant to twice the maximum working pressure
- no leakage

17. ISO 19932 requirements….
• HARNESS
- adjustable
- quick release (double shoulder)
- non absorbent material
- shoulder straps at least 25 mm or 50 mm
(>10 kg) wide
-Waist strap

18. ISO 19932 requirements….
• SPRAY TANK
- contents gauge accuracy
- material UV light resistant
- filling opening at least 100 mm wide
- nominal volume to be filled in within 60 s
- complete drainage (50 ml)
• CONTROLS
- quick acting shut-off device (no unintentional
opening, easy to unlock)
- pressure regulator (adjustable or changeable)

19. ISO 19932 requirements….
•HOSES
- at least 1200 mm long
- no sharp bends
•FILTERS
- filling filter with 0.5 to 2 mm mesh width
- easy to be changed and cleaned
•SPRAY LANCE AND NOZZLES
- spray lance at least 500 mm long
- possible to mount standard nozzles
- nozzle flow rate must not deviate by more than 10%
from specification

20. ISO 19932 test methods
• Functional tests
- shut-off device reliability
- spray liquid output
- strap drop test
- inclination test
- contents gauge accuracy and total volume test
- filling test
- emptying test
- absorbency test for straps
- chemical resistance of materials
- technical residue test
- external deposit volume test
- drop test
• Pressure test
• Leakage test
• Center of gravity

21. Tests

22. Strap test failures
Broken hooks
Broken fixing point

23. Personal Protective Equipment (PPE)
use in pesticide application

25. !
!!!!!
!!!

26. Protective suit contamination after using LK
sprayer (source: King and Dobson, 1992)

27. NOZZLES

28. Herbicides
Reflex
Hollow coneFlat fan
Fungicides,
Insecticides
Nozzle choice

29. Types Pressure Spray Advantages
(bar) quality
Reflex 1 Coarse Wide angle / less drift
Hollow cone 3 Fine Good coverage
Flat fan: Even spray 2 Medium / Coarse Narrow angle
Nozzle types

30. CALIBRATION

31. What is calibration?
• Calibration means testing your spraying
equipment with water and measuring how
much it can apply on a given area when
walking at a given speed using a given
pressure and keeping the nozzle at a given
height, so that one is able to know;
How much water he/she will need
How much chemical will be needed
How many sprayer full tanks will be needed
How much chemical to add per full tank

32. How is calibration done?
• Method 1: Tank method
• Method 2: Kalibottle method

33. CALIBRATING LK knapsack sprayer
Tank method
Add clean water up to a recognizable mark

34. CALIBRATING LK knapsack sprayer
Tank method
20 m
5 m
Spray a given measured area

35. CALIBRATING LK knapsack sprayer
Tank methodAfter spraying the given area;
Fill measuring jug
to top mark
Add water till you reach
same content as before
spraying
How much water have you
used for refill ?

36. CALIBRATING LK knapsack sprayer
Tank method
Therefore l used for spraying 100 sqm x 100 = l/ha
Calculate l/ha based on the amount of water used for example100 m2
:

37. CALIBRATING LK knapsack sprayer
Finding the chemical dose rate with
the Syngenta wheel:
A: calibrated l/ha to be aligned with
B: kg or l/ha chemical dose rate
Find
C: sprayer capacity
Read
D: chemical dose to be added per tank
full
A
B
C
D

38. CALIBRATING LK knapsack sprayer
Using formulas to find out how much chemical to add per tank full:
Pesticide dose rate (ml)
= ml / tank
Tanks / hectare
Calibrated l/ha
= Tanks / hectare
L / tank full

39. CALIBRATING LK knapsack sprayer
Kalibottle method
1. Use a clean sprayer with clean water
2. Check sprayer works correctly and safely
3. With correct nozzle height, measure swath width
4. Practise spraying at comfortable working speed
and with correct nozzle height
5. Attach Kalibottle and hold vertical
6. Spray 25 square metre
7. Read off volume rate

40. CALIBRATING LK knapsack sprayer
KALIBOTTLE method

41. CALIBRATING LK knapsack sprayer
KALIBOTTLE method
Walking – “spraying” 25 sqm
Reading “l/ha”
Repeat to be sure “

42. In summary (kalibottle method)
1. Fill the knapsack spray tank to maximum rated capacity with clean
water.
2. Set the correct operating pressure.
3. Spray holding the nozzle at the required height and measure the
swath width.
4. Using the calibration chart find out how far you must walk to cover
25 or100m2
Most nozzles have an optimum height of
50cms above the first intercepting
surface

43. ……..
5. Measure out the required distance to enable you to spray 25
or100m2
(this should preferably be done in the intended spray area
to provide a reliable walking speed).
6. Prime the sprayer and fill the tank to the maximum rated graduation
line or if there is no line fill to the top.
7. Walking at an even speed spray the 25 or100m2
, recording the
amount of time taken to complete the task (if you spray more than
one row do not record the time taken turning at the end of each
row).
8. Refill the sprayer to the same level as in step 6 recording the
amount of water required.
9. Using the calibration chart find out the application volume per ha.
10. Record all the results on the calibration form.
11. Repeat steps 7 to 10 three times to ensure accuracy.

44. END
Aggrey Atuhaire
Agric. Coordinator
PHE Uganda Project/UNACOH