Drift Reduction And Nozzle Selection Drift Reduction And Nozzle Selection Jim Wilson South Dakota State University Jim Wilson South Dakota State University

Introduction

Philosophical Tool #1 “They need to know that you care – Before they care what you know” “They need to know that you care – Before they care what you know”

Philosophical tool #2 Applicators are hands-on people Familiar is comfortable Seaman Knapp ? Have then do something Applicators are hands-on people Familiar is comfortable Seaman Knapp ? Have then do something

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 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

Drift Management 101 What’s the best nozzle? It depends What are you spraying? What do you need to know? What’s the best nozzle? It depends What are you spraying? What do you need to know?

Need to Know Fungicide? Insecticide? Herbicide? Contact/systemic? Broadleaf/grass Small vs large plants Canopy? Fungicide? Insecticide? Herbicide? Contact/systemic? Broadleaf/grass Small vs large plants Canopy?

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 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 size Pressure at nozzle tip Nozzle type Release height Nozzle orifice size Pressure at nozzle tip Nozzle type Release height Sprayer Factors Affecting Droplets that You Control } droplet size droplet size

How do you manage drift? Droplet size

(Droplet) Size Matters All droplets not created equal Droplets < 150 microns contribute most to droplet drift Droplets ~200 – 250 are target for fungicides All droplets not created equal Droplets < 150 microns contribute most to droplet drift Droplets ~200 – 250 are target for fungicides

Cutting Droplet Size in Half 500 Microns 500 Microns 250 Microns 250 Microns 250 Microns 250 Microns 250 Microns 250 Microns 250 Microns 250 Microns 250 Microns 250 Microns 250 Microns 250 Microns 250 Microns 250 Microns 250 Microns 250 Microns one droplet = eight droplets

↑ What’s the Difference between 200 vs 250u 250 Microns 250 Microns 200 Microns 200 Microns

↑ Droplet Size X ~1.26 = 2X weight 250 Microns 250 Microns 200 Microns 200 Microns = 2 X weight 250 Microns 250 Microns 200 Microns 200 Microns = 2 X volume 158 Microns 158 Microns 200 Microns 200 Microns 158 Microns 158 Microns 200 Microns 200 Microns

How are Nozzles categorized? ASAE 572 Droplet size standard Makes life easier ASAE 572 Droplet size standard Makes life easier ~ Very Fine MediumCoarseVery Coarse Extremely coarse DV.5 ц< >655

Differences in Micron sizes Don’t get hung up on u Based on reference nozzle Differences in droplet analyzing equip Category size should be similar Don’t get hung up on u Based on reference nozzle Differences in droplet analyzing equip Category size should be similar

Temperature & humidity Temperature & humidity Some Factors Affecting Drift

Evaporation of Droplets Wind High Relative Humidity Low Temperature Low Relative Humidity High Temperature Fall Distance

Temperature & humidity Air movement (direction and velocity) - meter Air stability crop canopy micro-inversions Temperature & humidity Air movement (direction and velocity) - meter Air stability crop canopy micro-inversions Some Factors Affecting Deposition

How do we pick a nozzle? What are you spraying? Know droplet categories Start with nozzle chart What fits travel speed/pressure Calibrate What are you spraying? Know droplet categories Start with nozzle chart What fits travel speed/pressure Calibrate

Glyphosate Applications? Coarse or larger droplets for most applications should give good control Coarse or larger droplets for most applications should give good control

Flat Fan ASAE Categories example

Nozzle Technology? What’s the difference?? Improved drop size control Emphasis on ‘Spray Quality’ Improved drop size control Emphasis on ‘Spray Quality’

Turbulence chamber nozzle (TurboTeejet)

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 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)

Differences in Air Induction ?

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 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! The right nozzle may be the most important component on your sprayer The wrong nozzles will make the most expensive sprayer operate poorly 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 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 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

Nozzle Selection Summary Use biggest droplets that will do job Manage sprayer to manage droplets One nozzle won’t do it all 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 Search for “Nozzles” Search for “Nozzles” Out of Print

Some Slides provided by: Dr. Robert E. Wolf Ext. Agricultural Engineer Kansas State University Questions