Adjuvants and How They Influence Application Practices

Robert E. Wolf Extension Specialist Application Technology

Biological and Agricultural Engineering

2

The Pesticide Application Process

Creating the Spray Solution

Atomization

Drop Transport to Target

Impaction / Deposition

Post-Impact Drop BehaviorRetention – Spreading – Penetration – Translocation

Biological Effect

Contact Action Systemic Action

3

• Many different attempts to define

• An adjuvant is broadly defined as any substance added to the spray tank, separate from the pesticide formulation, that will improve the performance of the pesticide.

• Spray adjuvants…modify the applied crop protection product to increase its efficacy.

What is an adjuvant?

4

• ASTM - E1519: A material added to a spray tank mix to aid or modify the action of an agrichemical, or the physical characteristics of the mixture.

• Adjuvants and surfactants are added to spray solutions to improve the performance of crop protection compounds (herbicides).

What is an adjuvant?

Adjuvant Categories Based on Herbicide Label Recommendations

Nonionic Surfactants (NIS)Crop Oil Concentrates (COC)

High Surfactant Oil Concentrates (HSOC)Modified Seed Oil (MSO, ESO)

Ammonium Fertilizers (UAN, AMS)Deposition Aids (Drift control, retention)

Activator Adjuvants

Additional Adjuvant Types

Improve the spray application processWater conditionersCompatibility aids

pH adjustersAntifoam/defoaming aids

Drift reduction/deposition aidsDyes/colorants/foam markers

Utility Adjuvants

Not All Adjuvants are the Same

Untreated Nicosulfuron Alone

+ 0.1% NIS + 0.2% NIS

Adjuvant descriptors:

WettingSpreading

StickingSoftening Water

Improving AbsorptionDrift Reducing

DefoamingMultipurpose?

Utility Adjuvants

Drift Reduction/Deposition Aids:

• Many available!• Not EPA regulated• Long chain polymers• Soluble powders• 50 - 80% reduction in off-target

movement• Not all will work!!!!• Pump shear problems• Effect on the pattern?

Drift Study

Product Name Product Company Mixing ratea

Tap water 1 Local supply X-77 only

Superb HC + Interlock Winfield Solutions 133 oz + 33 oz / 50 gal

Formula 1 United Suppliers 1.5 qt / 50 gal

#PX056-Z Precision Labs, Inc 5 qt / 50 gal

Tap water 2 Local supply X-77 only

Ag 06037 Winfield Solutions 64 oz / 50 gal

Ag 08050 Winfield Solutions 80 oz / 50 gal

Interlock 1.25 Winfield Solutions 80 oz / 50 gal

Control GarrCo Products, Inc 2 oz /50 gal

Tap water 3 Local supply X-77 only

INT 908 Rosen’s 5 gal / 45 gal

Tap water + Prime Oilb Local supply + Winfield Solutions 266 oz / 50 gal

Interlock 0.8 Winfield Solutions 50 oz / 50 gal

a All tank mixes included X-77 at .25% v/v (16 ounces per 50 gallon load).bOil to simulate a suggested tank mix with fungicide (Prime Oil @ 1 pint/acre).

Materials and Methods (2008):• AT 502A(Rucker Flying Service)

– Drop booms– CP-11TT #15 straight stream nozzles w/8° deflection– 44 PSI– 156 mph ground speed by GPS– Droplet spectrum: Medium, %volume <200 = 7.65%

• Aircraft calibrated for 3 GPA

Treatment VMD’s:

Tap W

ater 1

Superb HC + In

terlock

Form

ula 1

#PX056-Z

Tap W

ater 2

AG 06037

AG 08050

Interlock

1.25

Control

Tap W

ater 3

INT 908

Tap W

ater +

oil

Interlock

0.80

50100150200250300350400450

374 380 398 393345 331 333 348 336

368 356 347379

Treatment VMD

Mic

ron

Size

Total Drift Ranked:

INT 908

Control

Interlock

0.8

Tap W

ater +

oil

Tap W

ater 3

Tap W

ater 1

Form

ula 1

Interlock

1.25

Tap W

ater 2

Superb

HC + Inter

lock

#PX056-Z

AG 06037

AG 080500.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

36.5 37.7 37.8 41.6 44.1 50.1 53.3 53.9 57.7 61.5 63.571.4 74.6

a

cde de

ef effg

g

aaabc

ab

bcd cde

water average

% A

rea

Cov

erag

e

Corn Fungicide Studies

Plot 65 ft.

Center rowRow 1

Card & Plant heights

Row 10

Treatment Affect on Droplet Size in Arkansas

150200250300350400

2 3 4 5 6 7 8 9

Treatments

Mic

rons

Treatment Affect on Droplet Size - Kansas

150200250300350400

2 3 4 5 6 7 8 9 10

Treatments

Mic

rons

2. Crop Oil Concentrate (COC)3. Non-ionic Surfactant (NIS) 4. Methylated Seed Oil (MSO) & NIS &

Controlled Release Fertilizer (25-0-0 B)

5. NIS & Interlock 6. Quilt & NIS

7. MSO + Organosilicone Surfactant Blend & Controlled Release Fertilizer (25-0-0 B)

8. High Surfactant Oil Concentrate & Interlock

9. NIS + AG 0603710. NIS + AG 06038

Treatment Affect on Droplet Size - Western Illinois

150200250300350400

2 3 4 5 6 7 8 9 10

Treatments

Mic

rons

Treatment Affect on Droplet Size - Eastern Illinois

150200250300350400

2 3 4 5 6 7 8Treatments

Mic

rons

AR 9. COC + Control

NS

NSabb ab ab ab ab ababa

bcc bcab ca

bcbc

2007

Means for Percent Area Coverage Bottom Collectors

0.345

0.517

0.180

0.3550.303

0.525

0.2220.273 0.270

0.180

0.00

0.10

0.20

0.30

0.40

0.50

0.60

1 2 3 4 5 6 7 8 9 10

Treatments

% C

over

age

ABC ABC

CDE

CDE

CDECDE

CDE

BCD

AB A

6. USEX0208 @ 4 oz7. USEX0208 @ 8 oz8. USEX0308 @ 4 oz 9. USEX0308 @ 8 oz10. SRN-28 + Between @ 8 oz

All treatments – Headline @ 6 ounces/acre

1. Premium COC @ 16 oz2. Between @ 8 oz3. Downdraft @ 4 oz4. USEX0108 @ 4 oz5. USEX0108 @ 8 oz

2008

2009

Solution Factor:

• Changes the flow rate ?????• Changes the droplet spectra !!!!

Droplet Studies

Volume Median Diameter (VMD)

050

100150200250300350400450500

11004XR 11004TT TF 2 11003AI

Mic

rons

Water RWM + 2%AMSRWM + 1% AMS + Array RWM + 2% AMS + BorderRWM + 2% AMS + Placement

40 psi 40 psi 40 psi 70 psi

% less than 210 Microns

37 51 36 35 45 23 30 14 15 26 19 22 14 13 22 10 17 29 29 15

Bob Klein, U of Nebraska

Percent fines

Need to evaluate droplets of solutions:

CP11TT4015 Flat-Fan

140 MPH40 PSI23 degree orientation

ASC D-12 Rotary Atomizer

140 MPH26 PSI2 GPABlade pitch #2

ASC D-12 Rotary Atomizer

WW+Q

W+Q+FF

W+Q+NIS

W+Q+COC

W+Q+DEP0.05.0

10.015.020.025.030.035.040.045.0

20.1

38.433.1

30.3 32.823.9

%<100

Treatments

Mic

rons

WW+Q

W+Q+FF

W+Q+NIS

W+Q+COC

W+Q+DEP0

50

100

150

200

250

178

122 135 144 136

203

DV0.5

Treatments

Mic

rons

140 MPH26 PSI2 GPABlade pitch #2

Treatments• Water• Water + Quilt• Water + Quilt + Foliar Fertilizer• Water + Quilt + NIS• Water + Quilt + COC• Water + Quilt + Deposition Aid

CP11TT4015 Flat-Fan

WW+Q

W+Q+FF

W+Q+NIS

W+Q+COC

W+Q+DEP0

50100150200250300350400

335217 217 214 223 238

DV0.5

Treatments

Mic

rons

WW+Q

W+Q+FF

W+Q+NIS

W+Q+COC

W+Q+DEP0.02.04.06.08.0

10.012.014.016.018.020.0

4.2

12.815.2 14.1 13.1

17.5

%<100

Treatments

Mic

rons140 MPH

40 PSI23 degree orientation

Treatments• Water• Water + Quilt• Water + Quilt + Foliar Fertilizer• Water + Quilt + NIS• Water + Quilt + COC• Water + Quilt + Deposition Aid

Ground Nozzle Field Trials

TT 110025

AIXR 110025

AIC 11002

AM 110025

GA 110025

TDHSTF 1

1002

TTJ60 110025

ULD 12002

IDKT 120030

100200300400500600

418479 470 490 483

447 394 450 450

VMD - Glyphosate + Water + AMS

Nozzle Type

Mic

rons

TT 110025

AIXR 110025

AIC 11002

AM 110025

GA 110025

TDHSTF 1

1002

TTJ60 110025

ULD 12002

IDKT 120030

100200300400500600

421484 515 484 483 471

419501 554

VMD - Paraquat + Water + NIS

Axis Title

Mic

rons

Solution Effect – College Station in the Wind Tunnel

TT AIXR GA BFS AM AIC ULD TTI0

100

200

300

400

500

600

Water Glyphosate Paraquat

Nozzle Type

Mic

rons

Solution Effect - North Platte - Lab Using Product

Nozzle Type PSI Water Glyphosate Paraquat

TT110025 40 302 314 272

AIXR110025 40 438 410 429

AM110025 40 427 415 427

GA110025 40 414 367 397

TTJ60110025 40 340 370 290

AIC11002 70 488 428 423

ULD12002 70 347 339 342

TDHSTF11002 70 403 363 385

Summary

• Adjuvants allow for more consistent pesticide activity and should be viewed as a safety net for performance.– Adjuvants optimize pesticide efficacy

• In general, adjuvants don’t create value….they retain the value of the pesticide.

Summary cont’d

• The idea of superior adjuvants allowing for reduced pesticide application rates to save money should be discouraged.

• This may have only been true with glyphosate.

• The next 10 years will rely on herbicides without large amounts of rate flexibility so the goal of the adjuvant will be to simply just achieve acceptable control levels.

Calibration!!!!The next phase!

Ensuring that the spray droplet spectrum is what it is supposed to be to maximize

efficacy while minimizing drift!

ASABE S-572 Droplet Size Standard

Spray quality categories.

ASABE Standard S-572.1Category (symbol) Color CodeExtra Fine (XF) Purple

Very Fine (VF) Red

Fine (F) orange

Medium (M) yellow

Coarse (C) Blue

Very Coarse (VC) Green

Extra Course (XC) White

Ultra Coarse (UC) Black

2009

Page 4

Fact Sheet: MF2869

www.bae.ksu.edu/faculty/wolf/

Disclaimer:

• Brand names appearing in this presentation are for identification and illustration purposes only.

• No endorsement is intended, nor is criticism implied of similar products not mentioned.

www.bae.ksu.edu/faculty/wolf/Thanks!

For more information contact: rewolf@ksu.edu