Drift Reduction And

Nozzle Selection

Drift Reduction And

Nozzle SelectionJim Wilson

South Dakota State UniversityJim Wilson

South Dakota State University

IntroductionIntroduction

Philosophical Tool #1Philosophical Tool #1“They need to know that

you care – Before they care what you

know”

Philosophical tool #2Philosophical tool #2

Applicators are hands-on people

Familiar is comfortable

Seaman Knapp ?

Have then do something

What is Drift?What is Drift?

Movement of spray particles and vapors off-target causing

less effective control and possible injury to susceptible

vegetation and wildlife.

Adapted from National Coalition on Drift Minimization 1997 as adopted from the AAPCO Pesticide Adapted from National Coalition on Drift Minimization 1997 as adopted from the AAPCO Pesticide Drift Enforcement Policy - March 1991Drift Enforcement Policy - March 1991

Drift Management 101

Drift Management 101

What’s the best nozzle?

It depends

What are you spraying?

What do you need to know?

Need to KnowNeed to Know

Fungicide? Insecticide? Herbicide? Contact/systemic?

Broadleaf/grassSmall vs large plants

Canopy?

Need to KnowNeed to Know

One nozzle will not work well for all

When managing drift Use the biggest droplet

(w/ least fines)

That will do the job

Nozzle orifice sizePressure at nozzle tipNozzle typeRelease height

Sprayer Factors Affecting Droplets that You ControlSprayer Factors Affecting Droplets that You Control

}dropletsize

dropletsize

How do you manage drift?

How do you manage drift?

•Droplet size•Droplet size•Droplet size

(Droplet) Size Matters (Droplet) Size Matters

All droplets not created equalDroplets < 150 microns contribute most to droplet drift

Droplets ~200 – 250 are target for fungicides

All droplets not created equalDroplets < 150 microns contribute most to droplet drift

Droplets ~200 – 250 are target for fungicides

Cutting Droplet Size in Half

Cutting Droplet Size in Half

500Microns

500Microns

250Microns

250Microns

250Microns

250Microns

250Microns

250Microns

250Microns

250Microns

250Microns

250Microns

250Microns

250Microns

250Microns

250Microns

250Microns

250Microns

one droplet = eight droplets

↑ What’s the Differencebetween 200 vs 250u

↑ What’s the Differencebetween 200 vs 250u

250Microns

250Microns

200Microns

200Microns

↑ Droplet Size X ~1.26 =

2X weight

↑ Droplet Size X ~1.26 =

2X weight250

Microns250

Microns200

Microns200

Microns = 2 X weight

250Microns

250Microns

200Microns

200Microns = 2 X volume

158Microns

158Microns

200Microns

200Microns

158Microns

158Microns

200Microns

200Microns

How are Nozzles categorized?

How are Nozzles categorized?

ASAE 572 Droplet size standard

Makes life easier

~Very

Fine

Fine Medium Coarse Very

Coarse

Extremely coarse

DV.5 ц <182 183-280

281-

429

430-531

532-655

>655

Differences in Micron sizesDifferences in Micron sizes

Don’t get hung up on uBased on reference nozzleDifferences in droplet analyzing

equipCategory size should be similar

Temperature & humidity

Some Factors Affecting DriftSome Factors Affecting Drift

Evaporation of DropletsEvaporation of Droplets

Wind

High Relative HumidityLow Temperature

Low Relative HumidityHigh Temperature

Fal

l Dis

tanc

e

Temperature & humidity Air movement (direction and velocity) - meter

Air stabilitycrop canopy micro-inversions

Some Factors Affecting Deposition

Some Factors Affecting Deposition

How do we pick a

nozzle?How do we pick a

nozzle?What are you spraying?Know droplet categoriesStart with nozzle chartWhat fits travel speed/pressureCalibrate

Glyphosate Applications?Glyphosate Applications?

Coarse or larger dropletsfor most applications

should give good control

Flat Fan ASAE Categories

example

Flat Fan ASAE Categories

example

Nozzle Technology? What’s the difference??

Nozzle Technology? What’s the difference??

Improved drop size controlEmphasis on ‘Spray Quality’

Turbulence chamber nozzle (TurboTeejet)

Turbulence chamber nozzle (TurboTeejet)

Air/Induction – Venturi Nozzle:

Air/Induction – Venturi Nozzle:

• Spraying Systems AI TeeJet• Air intake venturi section• Mixing Chamber - air and spray

solution blended• Exit orifice - Pattern tip - forms

large air-bubble drops

Improved coverage ??Adequate efficacy ??Reduced drift? YES!!!

Source: Successful Farming – Feb. 2004

Air Induction Droplet Categories (example)

Air Induction Droplet Categories (example)

Differences in Air Induction? Differences in Air Induction?

Drift Reducing AgentsDrift Reducing Agents

increase viscosity/reduce driftable fines

? additional cost vs. drift reduction

may also affect pattern

may be different w/different A.I.s

New Nozzles?That’s Too Expensive!

New Nozzles?That’s Too Expensive!

• The right nozzle may be the most important component on your sprayer

• The wrong nozzles will make the most expensive sprayer operate poorly

What is the cost of drift?What is the cost of poor control?

What is the cost of drift?What is the cost of poor control?

Strategies to Reduce DriftStrategies to Reduce DriftSelect nozzle to increase drop sizeIncrease flow rates – higher application volumesUse proper pressuresUse lower spray (boom) heightsAvoid adverse weather conditionsConsider using new technologies:

drift reduction nozzles

Nozzle Selection Summary

Nozzle Selection Summary

Use biggest droplets that will do job

Manage sprayer to manage droplets

One nozzle won’t do it all

FS 919

Choosing Drift Reducing Nozzles

FS 919

Choosing Drift Reducing Nozzles

http://agbiopubs.sdstate.edu

Search for “Nozzles”

http://agbiopubs.sdstate.edu

Search for “Nozzles”

Out of

PrintOut o

f

Print

Some Slides provided by:Dr. Robert E. Wolf

Ext. Agricultural EngineerKansas State University

QuestionsQuestions