Drift Reduction

1
Physical Philosophical
Tools for Trainers

• Drift Reduction
• And
• Nozzle Selection

Jim Wilson South Dakota State University
2
Introduction
3
Philosophical Tool 1

• They need to know that you care
• Before they care what you know

4
Philosophical tool 2

• Applicators are hands-on people
• Familiar is comfortable
• Seaman Knapp ?
• Have then do something

5
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 Drift Enforcement Policy - March 1991

6
Drift Management 101

• Whats the best nozzle?
• It depends
• What are you spraying?
• What do you need to know?

7
Need to Know

• Fungicide? Insecticide? Herbicide?
  Contact/systemic?
• Broadleaf/grass
• Small vs large plants
• Canopy?

8
Need 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

9
Sprayer Factors Affecting Droplets that You
Control

• Nozzle orifice size
• Pressure at nozzle tip
• Nozzle type
• Release height

droplet size
10
How do you manage drift?

• Droplet size
• Droplet size
• Droplet size

11
(Droplet) Size Matters
All droplets not created equal Droplets lt 150
microns contribute most to droplet
drift Droplets 200 250 are target for
fungicides
12
Cutting Droplet Size in Half
one droplet eight droplets
250 Microns
250 Microns
500 Microns
250 Microns
250 Microns
250 Microns
250 Microns
250 Microns
250 Microns
13
? Whats the Differencebetween 200 vs 250u
250 Microns
200 Microns
14
? Droplet Size X 1.26 2X weight
200 Microns
250 Microns
158 Microns
200 Microns
2 X weight
200 Microns
250 Microns
200 Microns
158 Microns
2 X volume
15
How are Nozzles categorized?

• ASAE 572 Droplet size standard
• Makes life easier

Very Fine Fine Medium Coarse Very Coarse Extremely coarse
DV.5 ? lt182 183-280 281- 429 430-531 532-655 gt655

16
(No Transcript)
17
Differences in Micron sizes

• Dont get hung up on u
• Based on reference nozzle
• Differences in droplet analyzing equip
• Category size should be similar

18
Some Factors Affecting Drift

• Temperature humidity

19
Evaporation of Droplets
High Relative Humidity Low Temperature
Low Relative Humidity High Temperature
Fall Distance
Wind
20
Some Factors Affecting Deposition

• Temperature humidity
• Air movement (direction and velocity) - meter
• Air stability
• crop canopy micro-inversions

21
How do we pick a nozzle?

• What are you spraying?
• Know droplet categories
• Start with nozzle chart
• What fits travel speed/pressure
• Calibrate

22
Glyphosate Applications?

• Coarse or larger droplets
• for most applications
• should give good control

23
Flat Fan ASAE Categories example
24
(No Transcript)
25
Nozzle Technology? Whats the difference??

• Improved drop size control
• Emphasis on Spray Quality

26
Turbulence chamber nozzle (TurboTeejet)
27
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!!!
28
Source Successful Farming Feb. 2004
29
Air Induction Droplet Categories (example)
30
Differences in Air Induction?
31
Drift Reducing Agents

• increase viscosity/reduce driftable fines
• ? additional cost vs. drift reduction
• may also affect pattern
• may be different w/different A.I.s

32
New Nozzles?Thats 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?
33
Strategies to Reduce Drift

• Select nozzle to increase drop size
• Increase flow rates
• higher application volumes
• Use proper pressures
• Use lower spray (boom) heights
• Avoid adverse weather conditions
• Consider using new technologies
• drift reduction nozzles

34
Nozzle Selection Summary

• Use biggest droplets that will do job
• Manage sprayer to manage droplets
• One nozzle wont do it all

35
FS 919 Choosing Drift Reducing Nozzles
http//agbiopubs.sdstate.edu Search for
Nozzles
Out of Print
36
Questions
Some Slides provided by Dr. Robert E. Wolf Ext.
Agricultural Engineer Kansas State University