The application method you choose depends on such factors as the nature and habits of the target pest, characteristics of the target site, and properties of the pesticide formulation.

1. Pesticide Application
Equipment
LNT 136 – Spring 2017
Mark Valen

2. Pest and Disease in the News
Pest Compromising San Diego County's $126M Citrus
Crop May Call for Concerted Attack
• County Board of Supervisors will consider whether to form a special
district to combat the Asian citrus psyllid and HLB
• The county is under quarantine, but the disease hasn't been found locally
• HLB or citrus greening disease, has been located in eastern and southern
portions of Los Angeles County.

3. Pesticide Application Equipment
• Many pesticide products that the public purchases
and uses are ready‐to‐use (RTU) formulations
which require no dilution and can be applied
quickly and conveniently. Examples of ready‐to‐use
formulations used by homeowners are granules for
insect and weed control and baits for rodent
control.

4. Pesticide Application Equipment
• Many of the formulations used by farmers and
commercial applicators need to be applied with
certain equipment. These formulations may also
require certification or training for individuals
performing the application.
• The equipment required for the application is listed
on the label.

5. Pesticide Application Equipment
The first question that needs to be asked when
choosing the type of pesticide application equipment
to be used is whether a liquid or a solid pesticide
formulation will be used.

6. Pesticide Formulations
• A pesticide formulation is a
mixture of chemicals which
effectively controls a pest.
• Formulating a pesticide
involves processing it to
improve its storage, handling,
safety, application, or
effectiveness.
Pesticide Formulations
A Aerosol
B Bait
D Dust
DF Dry flowable
E,EC
Emulsifiable
concentrate
FL Flowable
G Granule
M Microencapsulated
P Pellet
RTU Ready‐to‐use
SP Soluble powder
ULV
Ultra‐low‐volume
concentrate
WP Wettable powder
WDG
Water‐dispersible
granule

7. Pesticide Formulations
• Mixture of active and other ingredients (previously
called inert ingredients).
• An active ingredient is a substance that prevents,
kills, or repels a pest or acts as a plant regulator,
desiccant, defoliant, synergist, or nitrogen stabilizer.
• Pesticides come in many different formulations due
to variations in the active ingredient's solubility,
ability to control the pest, and ease of handling and
transport.

8. Pesticide Formulations
• Synergists are a type of active ingredient that
enhance another active ingredient's ability to kill
the pest while using the minimum amount of active
ingredient, but do not themselves possess
pesticidal properties.

9. Pesticide Formulations
• Other (or inert) ingredients may aid in the
application of the active ingredient
• solvents ‐ liquids that dissolve the active ingredient
• carriers ‐ liquids or solid chemicals that are added to aid
in the delivery of the active ingredient
• adjuvants ‐ help make the pesticide stick to or spread
out on the application surface (i.e., leaves).

10. Pesticide Application Equipment
• Concentrated pesticides must be diluted to produce
a “tank mix”.

11. Unpowered Equipment
• Generally suitable for small applications, such
as spot treatments.
• Small unpowered equipment is inexpensive, simple
to use, and easy to clean and store.
• Small areas (less than an acre) can be treated by a
single person in a relatively short period of time.
However, calibration of small unpowered devices
can be difficult, and larger‐capacity liquid tank
sprayers may be difficult for physically smaller
technicians to handle.

12. Unpowered Equipment
• Typical unpowered equipment for liquid pesticides
includes some backpack and tank sprayers.
• Sometimes these types of equipment are called
compression sprayers.

13. Unpowered Equipment
• Unpowered backpack sprayers are really just tank
sprayers with straps to permit them to be carried like a
backpack.
• These sprayers sometimes have a continuously
operated pump lever to maintain pressure in the
pesticide tank. Others are pumped up by hand until
pressure reaches a certain point. The pesticide then can
be sprayed until the pressure drops below the level
where the sprayer works effectively. Then it must be re‐
pressurized. Pressurized tank sprayers and backpack
sprayers come in sizes ranging from about 1–5 gallons.
• Sprayers that are not backpack types are often referred
to as "hand can, or by their capacity, such as a "3‐gallon
sprayer."

14. Unpowered Equipment
• Pesticides in solid form (granules, slow release
briquettes, powders, etc.) can be applied by hand,
with small crank‐operated spreaders, dust cans, or
similar devices.
• Aerosol bombs are also unpowered pesticide
applicators.

15. Powered Equipment
For large‐scale pesticide applications, powered
equipment is essential.
• This type of equipment ordinarily is mounted in
vehicles, or attached to aircraft.
• Some backpack sprayers may use small 2‐cycle
engines as a power source, and some of these
miniature units have been used for ULV
applications.

16. Powered Equipment
• All power equipment works by pumping or blowing
product from a storage tank through a distribution line
or hose to various types of control mechanisms.
• The control mechanisms may be mounted on various
devices such as guns, booms, or cylinders that can be
aimed.
• For liquid products, the pesticide is applied
through nozzles which control the shape of the spray
pattern, the rate of flow of the spray, and the size of
individual spray droplets. Nozzles are available in many
sizes and configurations. Solid pesticides are spread
using hoppers or air streams to propel the particles.

17. Types of Power Applicators
There is a variety of powered application equipment
• tank sprayers
• mist blowers
• granular applicators
• ULV sprayers

18. Types of Power Applicators
Vehicles used with power applicators have become
highly specialized, and are often equipped with
complex computerized tracking devices that produce
maps of areas treated and records of vehicle speed,
wind velocity, temperature, and pesticide application
rates.

19. Sprayers
In commercial situations, the most commonly used
equipment is a sprayer that uses a combination of air and
liquid to deliver the pesticide to the target.
• Nearly 90 percent of these spray applications involve mixing
the pesticide into a liquid carrier (usually water) to aid in
delivering the pesticide to the target.
• Sprayers that utilize a liquid are classified as hydraulic
sprayers.
• In a few cases, the pesticide may be applied as an ultra‐low‐
volume spray where the pesticide is applied as formulated
and not mixed with water.
• Sprayer capacity can range in size from a few gallons (pump‐
up sprayers) to up to 1,000‐gallon sprayers pulled behind
tractors.

20. Sprayers
• Large sprayers have multiple nozzles on one or
more booms and use a pump to create pressure to
deliver the spray mixture into a stream of air flow
or toward the intended target.
• Smaller handheld or backpack sprayers usually have
a single nozzle and use compressed air to deliver
the spray mixture.

21. Sprayers
Sprayer components include:
• Tank
• Pump
• Hoses and Wands
• Nozzles
Larger applicators may have pressure
regulators, fans, filter screens, control valves,
booms, agitators

22. Sprayer Tank

23. Sprayer Tank
• The tank contains the liquid in which the pesticide is
diluted to create a spray solution.
• The tank should be made of a material that resists
corrosion and can easily be cleaned after application.
• Tanks require an opening in which filling, cleaning and
inspection can be conducted.
• The tank opening must be watertight to prevent
spillage while in transport.
• A person should never enter a large tank without
proper personal protection equipment (PPE) and only
after the tank has been determined to be safe to enter.

24. Sprayer Pump
• The pump supplies the needed pressure, volume to
the nozzles.
• Pumps should be designed to resist corrosion and
abrasion and be operated at a speed or pressure
recommended by the manufacturer.

25. Sprayer Hoses
• Hoses within the spray system should be made of a
material that will resist wear and not be damaged by
the spray solution.
• The hoses need to:
• be rated to have burst strength greater than the peak pump
operating pressure
• have a working pressure at least equal to the sprayer’s
maximum operating pressure
• resist oil and solvent that are in the pesticides
• resist sunlight
• The hoses should be inspected on a regular basis to
ensure they are in safe working condition. Hoses should
be replaced when showing signs of wear or
deterioration.

26. Sprayer Nozzles
• Nozzles control the amount of material applied, the
formation of the droplets, their size, and the
distribution and patterns of the droplet.
• The nozzle orifice size affects the droplet size and
flow rate. Larger orifices will produce larger droplet
sizes.

27. Sprayer Nozzles
• Nozzles can be made of brass, aluminum, plastic,
stainless steel or ceramic.
• When applying a pesticide, the applicator is legally
responsible for the proper application of the
pesticide. Proper training and supervision is a key
safety ingredient in any pesticide application.

28. Drift Mitigation Measures
Drift can be controlled by maximizing droplet size and controlling
the time the droplets are in the air.
To mitigate drift, consider the following options:
• Make applications in accordance with label directions.
• be aware of setback distances from nearby susceptible crops,
wind speeds and direction, and location of sensitive crops in your
area.
• Do not spray when wind speeds are greater than 10 miles per
hour.
• Also, be aware if relative humidity is below 50 percent and the
temperature is high, which increases the likelihood of off‐target
movement.
• If spraying with a boom, keep the boom as close to the target as
possible and use wide‐angle nozzles.

29. Drift Mitigation Measures
• Select a reasonable application speed. The site where the
sprays are being applied will ultimately determine ground
speed. Rough ground conditions will require slower speeds.
• Select the proper nozzle type and orifice (opening in nozzle)
size for each application method.
• Calibrate the sprayer and replace any worn or damaged
nozzles.
• Worn nozzles will impact spray patterns, droplet size and impact
coverage.
• Worn nozzles should never be saved for later use and should be
properly disposed of as they no longer provide the designed spray
pattern or application rate.
• Use higher spray volumes when possible. Selecting larger
nozzle orifices that produce higher spray volumes will
increase droplet size, which is less drift‐prone.