Applying pesticides correctly involves diluting the product (except 'Ready-to-Use' formulations) to the appropriate concentration and using calibrated application equipment.

1. Planning and Calibration
LNT 136 - Spring 2017
Mark Valen

2. Formulations
A pesticide formulation is a homogeneous and stable
mixture of active and inert ingredients which make
the final product simpler, safer, and more efficacious
to apply to a target pest.

3. Formulations
Common Formulation Types:
Dry - Sprayable
• WP – Wettable powders
• WG or WDG – Water dispersible granule
Liquid Sprayable
• SL – Soluble Concentrate
• SC – Suspension Concentrate
• EC – Emulsifiable Concentrate
• ME - Microemulsion
• OD – Oil Dispersion
• CS – Microencapsulated Particles
Dry – Spreadable Granule
• GR – Soil applied Granule on inert or fertilizer carrier

4. Wettable powder (WP)
A solid pesticide formulation – micronized to powder
form and typically applied as suspended particles
after dispersion in water.
Characteristics: simple but dusty, difficult to
measure, easy to mix into water

5. Water dispersible granule (WG)
A pesticide formulation consisting of granules to be
applied after disintegration and dispersion in water.
Characteristics: Low dust, simple to measure, more
time needed to disperse

6. Suspension concentrate (SC)
A stable suspension of solid pesticide(s) in a fluid
usually intended for dilution with water before use.
Characteristics: A.I. must be water insoluble with
friable crystals, Easy to tankmix (very compatible) -
A.I. tends to settle out over time.

7. Emulsifiable concentrate (EC)
A solution of a pesticide with emulsifying agents in a
water insoluble organic solvent which will form an
emulsion when added to water.
Characteristics: A.I. must be solublized in water
immiscible solvent. Solvents may increase toxicity to
operator/environment and degrades spray
equipment parts, freezing may initiate crystal
formation.

8. Residues Left After Application
Solid Crystals
• Wettable Powder
• Water Dispersible
Granule
• Suspension Concentrate
• Oil Dispersions
• Some Emulsifiable
Concentrates
• Some Solutions
Liquid Droplets
• Emulsifiable
Concentrates
• Micro-emulsions
Solutions

9. Spray Adjuvants
An adjuvant is added to a pesticide product or
pesticide spray mixture to enhance the pesticide’s
performance and/or the physical properties of the
spray mixture.
Examples of adjuvants include surfactants, oils,
compatibility agents, buffering and conditioning
agents, defoaming agents, deposition agents, drift
control agents, and thickeners.

10. Spray Adjuvants
Spray adjuvants can be categorized into two groups:
Activator adjuvants
• Improve the “activity” of the pesticide product.
• Generally lead to better absorption
Utility / Special-purpose adjuvants
• Modify the physical characteristics of the spray
solution.
• Minimize application problems.

11. Spray Adjuvants
Surfactants (surface acting agents)
AKA wetting agents and spreaders
physically change the surface
tension of a spray droplet.
Particularly useful when applying a
pesticide to a plant with waxy or
hairy leaves.

12. Spray Adjuvants
Nitrogen-based fertilizers
Improved herbicide activity has been shown by adding
ammonium sulfate or urea-ammonium nitrate to the
spray mixture.
Usually included in addition to a surfactant
Many fertilizer-based adjuvants are available in liquid
forms, which are easier to mix and provide more
consistent results.
Fertilizers should only be used with herbicides when
recommended by the label.

13. Spray Adjuvants
Compatibility agents
Pesticides are commonly mixed with liquid fertilizers or
other pesticides. However, some combinations can be
physically or chemically incompatible, causing clumps
and uneven distribution in the spray tank.
Occasionally, the incompatible mixture will clog the
pump and hoses, resulting in expensive cleanup and
repairs.

14. Spray Adjuvants
Jar Test for Compatibility of Pesticide Mixtures
Always wear personal protective equipment (PPE)
when pouring or mixing pesticides, even for this simple
test.
To conduct a jar test, add proportionate amounts of all
the products you intend to mix in the spray tank to a
clear quart jar. When using a liquid fertilizer carrier,
many herbicide labels recommend using two jars for
this test—one with and one without a compatibility
agent.
https://www.youtube.com/watch?v=YEmUwE4A5Ag

15. Spray Adjuvants
Jar Test for Compatibility of Pesticide Mixtures
Step 1. Measure 1 pint of water (or carrier solution)
into a clear quart jar. Use the same water source that
will be used in the tank mix.

16. Spray Adjuvants
Jar Test for Compatibility of Pesticide Mixtures
Step 2. Add proportionate amounts of each product, one at a
time, in the order suggested on the label, or add ingredients in
the following order. Stir each time a formulation has been
added.
• Compatibility, buffering, or defoaming agents (if needed)
• Wettable powders, dry flowables, water-dispersible granule
products
• Flowables, liquids, microencapsulated products
• Solutions, soluble powder products
• Remaining adjuvants, such as surfactants or crop oils (if
needed)
• Emulsifiable concentrates

17. Spray Adjuvants
Jar Test for Compatibility of Pesticide Mixtures
Step 3. Shake the jar vigorously and allow it to stand
for at least 15 minutes. The mixture is probably not
compatible if scum forms on the surface, the mixture
clumps, or any solids settle to the bottom (except for
wettable powders). Do not use a mixture that gives off
heat (determined by feeling the jar) as that indicates a
chemical reaction has occurred and changed the
chemical properties of the products.

18. Spray Adjuvants
Jar Test for Compatibility of Pesticide Mixtures
If a compatibility problem occurs, dispose of the
mixture according to the pesticide product label.
Finally, if no signs of incompatibility appear, put the
pesticide test mixture into the spray tank. In addition,
rinse all utensils and pour the rinse water (rinsate) into
the spray tank and apply to a labeled site. Do not use
utensils or jars for any other purpose after they have
contacted pesticides.

19. Spray Adjuvants
Drift control agents
Small droplets (with diameters of 150 microns or less) tend
to drift away from targeted areas.
• Improve on-target placement of the pesticide spray by
increasing the average droplet size.
Thickeners increase the viscosity of spray mixtures.
• Slow evaporation after the spray has been deposited on
the target area.
Slowing evaporation is important when using systemic
pesticides because they can penetrate the plant cuticle
only as long as they remain wet.

20. Spray Adjuvants
Tank Cleaners
Commercial tank cleaners are designed
to work with water and oil soluble
pesticide products and are often
recommended on pesticide labels.
Always refer to the label for
recommended tank cleaners with the
product being used.
Always follow label directions and wear
personal protective equipment when
cleaning a sprayer.

21. Spray Adjuvants
Colorants
Colorants are used to alter the color of spray solutions
to visually aid in the placement of the spray solution.

22. Calibration
Calibration is any adjustment you make to
application equipment and the procedures you
must follow so you know you’re applying the
correct amount of pesticide to a treatment area
OBJECT OF CALIBRATION
Apply uniformly, and in the desired areas, the proper
amount of active ingredient.

23. Calibration
When should you calibrate?
• Beginning of the season
• Anytime something changes that can affect the
application (output rate, travel speed, nozzles,
product, person making the application)
Use water for calibration.

24. Outline of procedure
The first step in calibrating spraying, dusting, or granulating
equipment is to read the entire label of the pesticide you are
about to use.
Next follow this check list:
1. Select nozzles to provide the proper application rate
within the recommended range of pressures.
2. Locate nozzles so that coverage is uniform.
3. Regulate the pressure to give proper nozzle discharge rate
and spray pattern.
4. Regulate and maintain ground speed for applying the
correct amount of pesticide.
5. Prepare to calibrate equipment correctly.

25. Outline of procedure
CALIBRATION OF HAND SPRAYERS (SINGLE NOZZLE)

26. Outline of procedure
CALIBRATION OF HAND SPRAYERS (SINGLE NOZZLE)
1. Mark off an area 10 feet by 10 feet.
2. Fill sprayer with water to known mark and spray
area.
3. Refill sprayer, measuring the amount of water
required to refill to original level.
4. Determine per acre rate of spray delivery

27. Outline of procedure
Amount of spray delivered per acre for nozzle
discharge per 100 sq. ft.
1/2 pint = 27 gal
1 pint = 55 gal
1 1/2 pints = 82 gal
1 quart = 110 gal

28. Outline of procedure
Example: To determine rate for wettable powder in
Hand Sprayer
The label prescribes 2 lbs per 55 gallons of water.
How much WP should be added to a 3 gallon
sprayer?
1 pound = 16 ounces

29. Outline of procedure
Example: To determine rate for wettable powder in
Hand Sprayer
The label prescribes 2 lbs per 55 gallons of water.
How much WP should be added to a 3 gallon
sprayer?
2 lbs. /55 gals. X x / 3 = 32/55 X x/3 gal =

30. Outline of procedure
Example: To determine rate for wettable powder in
Hand Sprayer
The label prescribes 2 lbs per 55 gallons of water.
How much WP should be added to a 3 gallon
sprayer?
2 lbs. /55 gals. X x / 3 = 32/55 X x/3 gal = 1.7oz.