Lecture 17 Application Equipment & Calibration

5 Common Pesticide Applications

1. Band Application

2. Broadcast Application

3. Foliar Application

4. Direct or Spot Spray

5. Soil Fumigation/Injection

5 Types of Sprayers (Liquid Formulation Equipment)

1. Hand-Operated Sprayers

2. Low Pressure Boom Sprayers

3. High Pressure Sprayers

4. Air Blast Sprayers

5. Ultra-Low Volume Sprayers

4 Types of Materials Used to Construct Spray Nozzles

1. Brass

2. Plastic

3. Stainless Steel

4. Ceramic

4 Types of Spray Nozzles

1. Hollow & Solid Cone Nozzles

2. Flat Spray Nozzles

3. Even Spray Nozzles

4. Flooding Nozzles

4 Types of Nozzle Spray Patterns

1. Circular Pattern

2. Fan Pattern

3. Narrow Rectangular Pattern

4. Wide Flat Pattern

4 Sprayer Calibration Stages

1. Check for uniform nozzle flow rate

2. Check for uniform nozzle spray pattern

3. Obtain the desired spray rate

4. Determine the amount of pesticide & water to add to spray tank

4 Variables for Which a Sprayer is Calibrated (Sprayer Constants)

1. Ground Speed

2. Spray Pressure

3. Number of Nozzles

4. Nozzle Orifice Size

This form of application places the pesticide in a strip over or beside a crop row

Band Application

This form of application applies the pesticide uniformly over an area

Broadcast Application

This form of application applies the pesticide directly to the top portions of a plant

Foliar Application

This form of application directs a pesticide at a target in small, discrete areas

Directed or Spot Spray

This form of application is beneath or incorporated into the soil surface

Soil Fumigation/Injection

Pesticide Sprayers — Primary Function

to deliver the pesticide at the proper rate on the proper target

What are the 2 forms of Dry Formulation Equipment?

1. Dusters

2. Granule Spreaders

Describe Dusters

blows fine particles of pesticide dusts onto the target surface

Describe Granule Spreaders

apply coarse, dry particles that are uniform in size to soil, water, and sometimes foliage

These sprayers use a relatively low volume of dilute spray ranging from 10-40 gallons/acre and applied at 30-60 psi

Low Pressure Boom Sprayer

These sprayers can be fitted with booms or handguns

High Pressure Sprayers

These sprayers use a fan or whirling disk to break up and blow spray droplets toward a target; use undiluted concentrate.

Ultra-Low Volume Sprayers (Mist Blowers)

Dusters — Advantages (4)

1. Lightweight

2. Cheap

3. Fast Acting

4. Don’t Require Water

Dusters — Disadvantages (3)

1. Highly Visible

2. Drift Easily

3. Difficult to Control

Granule Spreader — Advantages (4)

1. Light weight

2. Easy to calibrate

3. Water not needed

4. Granules Flow Easily + Relatively Heavy (because they are uniform in size)

Granule Spreader — Disadvantages (2)

1. Limited # of uses

2. Poisons non-target wildlife if granules left uncovered

Hand Operated Sprayers — Advantages (3)

1. Economical

2. Light-Weight

3. Easy to Control (direction, drift)

Hand Operated Sprayers — Disadvantages (2)

1. Frequent Poor Agitation

2. Wettable Powders clog regular nozzles

Low Pressure Boom Sprayer — Advantages (5)

1. Economical

2. Lightweight

3. Versatility

4. Wide Coverage

5. Low Volume (so one tank will cover a large area)

Low Pressure Boom Sprayer — What is the main Disadvantage? What does this cause?

Low Pressure that leads to inadequate penetration and coverage of dense foliage

High Pressure Sprayers — Advantages (3)

1. Strongly Built

2. Long Lasting

3. Dependable/Consistent

High Pressure Sprayers — Disadvantages (4)

1. Heavy

2. Expensive

3. Uses a lot of water

4. Pesticide can be easily misdirected

Air Blast Sprayers — What is the main Advantage?

Deliver the pesticide to hard-to-reach areas + through dense foliage

Air Blast Sprayers — Disadvantages (3)

1. Expensive

2. Wind interferes with application patterns

3. Perception that pesticides are missing the target

Ultra-Low Volume Sprayers — Advantages (3)

1. Saves time and labor

2. Light weight

3. Easy to use

Ultra-Low Volume Sprayers — Disadvantages (4)

1. Calibration is critical

2. Overdosage

3. Need favorable weather conditions

4. Increased risk to the applicator

Sprayer Nozzles — 3 Functions

1. Regulate Flow of liquid

2. Atomize Stream into droplets

3. Spread droplets in a Specific Pattern

Spray Nozzles regulate flow based on what?

the orifice size, as well as the pressure of the liquid

By how much should the pressure be increased in order to double the flow rate?

4x

True or False:

Flow rate decreases as pressure increases

false

True or False:

Flow rate increases as pressure decreases

false

True or False:

Flow rate increases as pressure increases

true

True or False:

Doubling the pressure doubles the flow rate

false

True or False:

Doubling the pressure does not double the flow rate

true

Sprayer Nozzles — atomization is caused by what?

the tearing action of air

Describe how Sprayer Nozzles atomize the stream

it spreads liquid into a thin unstable sheet which breaks into droplets as it hits the air

How is droplet size measured?

Microns (1/1,000,000 of a meter)

An increase in pressure does what to tearing action?

increases tearing action → smaller droplets

Sprayer Nozzles — what happens if the droplets are too small?

drift

Sprayer Nozzles — what happens if the droplets are too large?

poor retention

True or False:

Worn nozzles have poor spray patterns and lower flow rates

false

True or False:

Worn nozzles have poor spray patterns and higher flow rates

true

True or False:

Worn nozzles have decent spray patterns and predictable flow rates

false

True or False:

If the flow rate of the used tip is 10% greater than a new one, replace it

true

True or False:

If the flow rate of the used tip is 20% greater than a new one, wait to replace it

false

True or False:

If the flow rate of the used tip is 50% greater than a new one, replace it

false

True or False:

Clogged tips should be cleaned with a soft bristled brush only

true

True or False:

Clogged tips should be cleaned with a hard bristled brush only

false

True or False:

Sprayer nozzles are protected from grit and dirt with screens

true

True or False:

Sprayer nozzles are protected from grit and dirt with soft bristled brushes

false

True or False:

Never put a dirty, clogger nozzle to your mouth to clean it

true

True or False:

It is recommended to clean clogged sprayer nozzles by blowing through them with your mouth

false

True or False:

Materials used to construct spray nozzles are chosen for their cost and durability

true

True or False:

Materials used to construct spray nozzles are chosen for their appearance and color

false

This material is the most commonly used, is the least resistant to wear, and is relatively inexpensive

Brass (50 use hours)

This material can be used for corrosive chemicals, but it is also fragile. With modern grades and care, it is similar to stainless steel.

Plastic

This material has 2-3x or 4-6x brass wear

Plastic

This material is non-corrosive, has good wear resistance, and it relatively expensive.

Stainless Steel

This material is 4-6x brass wear

Stainless Steel

This material is the most durable tip for highly abrasive and/or corrosive chemicals

Ceramic

This material is 20-50x brass wear

Ceramic

These nozzles produce a circular pattern

Hollow & Solid Cone Nozzles

These nozzles produce a fan pattern with gradually tapered edges

Flat Spray Nozzles

These nozzles produce a narrow rectangular pattern with a sharp cut of edges

Even Spray Nozzles

These nozzles produce a wide flat spray pattern consisting of large droplets

Flooding Nozzles

These nozzles are used on handgun sprayers and row crop sprayers

Hollow & Solid Cone Nozzles

These nozzles are used to broadcast most types of pesticides

Flat Spray Nozzles

These nozzles are used for band applications, frequently used with planting equipment

Even Spray Nozzles

These nozzles are used broadcast application of fertilizers, herbicides, and defoliants

Flooding Nozzles

Pressure increases = Flow Rate ___

increases

Pressure increases 4x = Flow Rate ____

doubles

Pressure Increases = Droplet Size ___

decreases

Droplets too Small = Drift Risk ___

increases

Droplets too Large =

runoff/poor retention

Vehicle Speed Increases = ___ pesticide applied per acre

less

Vehicle Speed Decreases = ___ pesticide applied per acre

more

Spray Height Increases = ___ coverage area

wider

Spray Angle Increases = ___ coverage area

wider

Nozzle Nomenclature — 11004VS

110° Spray Angle

Nozzle Nomenclature — 11004VS

0.4 gal/min nozzle capacity rated at 40 PSI

(nozzle size)

Nozzle Nomenclature — 11004VS

Material (VisiFlo Stainless)

Nozzle Nomenclature — XR TEEJET

Nozzle type

Nozzle Nomenclature — XR TEEJET

Brand Name

Ground Speed — Faster speeds result in?

lower output per area

Ground Speed — Slower speeds result in?

increased output per area

Speed traveled over the ground will significantly affect?

sprayer output

Some product labels require that the pesticide be applied within a specific?

pressure range

High pressures present greater risks from?

drift

Changes in PSI will result in major changes in?

output

The number of nozzles is determined by the?

design configuration of the sprayer

In most cases, the number of nozzles will remain constant unless?

the sprayer is rebuilt or retrofitted

Nozzle size or type is the most practical method for?

adjusting sprayer output

Mixing Chemicals:

Acres per tankful = ____/____

tank capacity / spray rate