Spray Tip Update

Robert E. Wolf Extension Specialist

Biological and Agricultural Engineering

3-Ring Binder Materials:• 2003 Chemical Weed Control

– Pages 5-10• Application items – last tab

– Various publications– Windmeters– TeeJet Buyers Guide– Hypro Tip Guide

Nozzle Technology? How to use??• Nozzles designed to reduce drift• Improved drop size control• Emphasis on ‘Spray Quality’

Nozzles are important because:

• Control the amount – GPA.• Determine uniformity of application.

• Affects the coverage.• Influences the drift potential.

Coverage:• Need knowledge of the product being

used.– Systemic– Contact

• What is the target?– Soil– Grass– Broadleaf (smooth, hairy, waxy)– Leaf orientation – time of day

Will affect drift:• Movement of spray

particles off-target.• Creating smaller

spray drops will result in increased drift.

• Is it Coverage vs Drift?

• What is the answer?$64,000 Question?

Why Interest in Drift?• Spotty pest control• Wasted chemicals• Off-target damage• More high value specialty crops• Urban sprawl and.....• Less tolerant neighbors• Litigious Society• More wind?? (Timing)• Environmental impact

– Water and Air Quality• Public more aware of pesticide

concerns! (Negative) (Perceptions)• Result-higher costs-$$$

Spray Characteristics are Important to Understand:

Demonstrates Turbo Flat vs TurboDrop-5 MPH Wind

Page 7 - TeeJet

Page 4

Nozzles Types?

Is this tip good or bad?

Extended Range Flat-fan:• Tapered edge pattern• 80 and 110 degree fan• Requires overlap - 50 to 60%• 15-60 psi range

110°

80°

Nozzles Types?

Turbo Flat-fan: Turbulence chamber as in the Turbo Flood Tapered edge, wide angle flat pattern Designed to work in flat-fan nozzle holder Uniform spray distribution, 50-60% overlap Wide pressure range, 15 – 90 psi Large, drift resistant droplets Plastic with superior wear characteristics

TT

XR

Nozzles Types?

Air-Induction/Venturi NozzlesWhere air is drawn into the nozzle

cavity and exits with the fluid.

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

• Better Penetration?• Reduced run-off?• Improved coverage?• Adequate efficacy?• Reduced drift? YES!!!

Air/Induction – Venturi Nozzle:• Greenleaf – TurboDrop• Air intake venturi section• Mixing Chamber - air and

spray solution blended• Pattern tip forms large

air-bubble drops• Exit tip flow 2X venturi

orifice• Better Penetration?• Reduced run-off?• Improved coverage?• Adequate efficacy?• Reduced drift?

XR Flat-fan and Turbo Flat-fan compared to Venturi Style

5.0 MPH wind at 40 psi

XR vs TurboDrop Turbo Flat vs Turbo Drop

Driftable Droplets: Spraying Systems-2000Nozzle Type(0.5 GPM Flow)

Approximate % of SprayVolume < 200 Microns15 PSI 40 PSI

XR 11005 14% 22%XR 8005 6% 12%DG 11005 N/A 11%DG 8005 N/A 7%TT 11005 <1% <6%TF-2.5 <1% <1%AI 11005 N/A <1%

2001 Research Results

Objective of this study: Field measure the spray droplet

characteristics of venturi flat-fan nozzles at 50 PSI compared to extended range flat-fan nozzles at 25 PSI, and turbo flat-fan and DR flat-fan nozzles at 35 PSI.

Materials and Methods:Spray Tips (4):Extended Range Flat-fan (XR)

Turbo Flat-fan (TT)Combo-Jet DR Air Induction Flat-fan (AI)

Spray Volumes (2): 5 GPA (110015 orifice tips)10 GPA (110025 orifice tips)10 GPA (11003 orifice tips)

Application Ground Speed: 4.75 – 5.5 MPHSpray Pressure: 25, 35, and 50 PSISpray Tip Spacing: 30 inchesCanopy Boom Height: 21 inches

glyphosate

paraquat

Collection Procedure:

DropletScan used to analyze droplets:

System ComponentsSystem Components

XR AITT TTXR AI

Sample cards:

5 GPA 10 GPA

DR DR

Spray Droplet Size – Tip * Volume

328

370 440

523 483 531

591 595

100

200

300

400

500

600

700

Mic

rons

47 L/ha 94 L/ha

VMD Means - by Tip and Volume

173 kPa XR 242 kPa TT 242 kPa DR 345 kPa AI

XR AITT DR

5 GPA

10 GPA

Drift Potential – Tip * Volume

720

422

10568

773

374

152 139

0

100200300400500600700800900

1000

Mic

rons

47 L/ha 94 L/ha

Droplets <200 by Tip and Volume

173 kPa XR 242 kPa TT 242 kPa DR 345 kPa AI

XR AITT DR

5 GPA

10 GPA

Efficacy – Tip * Volume

89 8781 79 84 80

7478

0102030405060708090

100

Perc

ent C

ontro

l

47 L/ha 94 L/ha

Tip by Volume - Early (2 WAT)

173 kPa XR 242 kPa TT 242 kPa DR 345 kPa AI

XR AITT DR

5 GPA

10 GPA

LSD=2

2002 Research Results

Objective of this study:

• Compare the efficacy and spray droplet characteristics of three venturi flat-fan nozzles against the turbo flat-fan tip at 30, 50, and 70 psi.

Materials and Methods:Experiments: Location: Ashland Bottoms, Manhattan, KSExp. Design: 2 x 3 x 4 split-split plot with 3 reps (24 treatments)Drop Collectors: Placed in 2 reps with 2 cards per rep (96 cards)Plot Size: 3 x 9 m with 1.5 m bufferWeeds: Velvetleaf, common sunflower, sorghum, cornVisual Ratings:1, 2, and 4 weeks after treatment

Herbicides (2): Paraquat, 0.487 lb ae/a (1.3pt/a), NIS @ .25% v/vGlyphosate, 0.28lb ae/a (12 oz/a), AMSU @17 lb/100 gal

Application Volume: 10 GPAApplication Conditions: Date: July 09, 2002 Weed Size: Vele - 15 cm, Cosf - 20 cm, Sorg – 25 cm, Corn – 13 cm Temperature: 98 F R. H.: 20% Wind: S-SW@ 4-5 km/h

Spray Tips (4):Turbo Flat-fan (TT)Air Induction Flat-fan (AI)Ultra lo-drift (ULD)Air Mix (AM)

Spray Volume: 10 GPA (11002 orifice tips)Spray Pressure: 30, 50, and 70 psiSpray Tip Spacing: 76 cm, tilted 15 degreesCanopy Boom Height: 51 cm

Materials and Methods:

Collection Procedure:

Volume Medium Diameter:

549*

625*

571* 582

500

520

540

560

580

600

620

640

Mic

rons

TT AI AM ULD

VMD (50%)

*Significant .05

Control: Tip / Pressure

50

60

70

80

90

100

% C

ontr

ol

Velvetleaf Sunflower Sorghum Corn

Tip - 14 DAT

TT AI AM ULD

*

0

20

40

60

80

100%

Con

trol

Velvetleaf Sunflower Sorghum Corn

Pressure - 14 DAT

30 psi 50 psi 70 psi

*Significant

Example Reference Graph

Cumulative Volume Fraction

0.1 0.5 0.9

Drop S

ize (microns) 0

100

200

300

400

500

600

700

800

900

very fine/ fine fine/mediummedium/ coarsecoarse/ very coarsevery coarse/ extremely coarse

VF

F

M

CVC

XC

• New Label language-EPA Reviewing Public Comments

• Public ‘Listening Sessions’ planned

• Sometime in 200???• Match the crop

protection product to the target

• Adhere to label guidelines based on an industry standard – ASAE S-572

• Buffer Zones or No Spray Zones

• Maximize Efficacy• Minimize Drift

EPA Requested Changes Coming!?!?

Example Reference Graph

Cumulative Volume Fraction

0.1 0.5 0.9

Dro

p S

ize

(mic

rons

)

0

100

200

300

400

500

600

700

800

900

very fine/ fine fine/mediummedium/ coarsecoarse/ very coarsevery coarse/ extremely coarse

VF

F

M

CVC

XC

Origin Of Standardized Spray Droplet Size Categories

• 1985 -- British Crop Protection Council (BCPC)– Droplet size classifications, primarily

designed to enhance efficacy.– Uses the term SPRAY QUALITY for droplet

size categories.2000 -- ASAE Standard S572– Droplet size classifications, primarily

designed to control spray drift.– Uses the term DROPLET SPECTRA

CLASSIFICATION for droplet size categories.

ASAE DSC and Volume Median Diameter (DV0.5) From PMS* Laser

Spectrometer

• Very Fine (VF) < 182µm• Fine (F) 183-280µm• Medium (M) 281-429µm• Coarse (C) 430-531µm• Very Coarse (VC) 532-655µm• Extremely Coarse (XC) >656µm

*USDA ARS College Station, TX

Droplet Spectra Classification (DSC)

Droplet SizeRange

Page 4

Important Droplet Statistics:

Operational Area

Thanks

For more information contact:

www.bae.ksu.edu/rewolf/

rewolf@ksu.edu