Greg R. Kruger and Bradley K. Fritz

pat.unl.edu

Effective Application Technology Management for

Maximum Deposition and Coverage

2,4-D-resistant waterhemp

XR, Turbo TeeJet, and the TTI nozzle

XR

TT

XR, Turbo TeeJet, and the TTI nozzle

TTI

1 micron 100 micron 200 micron 400 micron 1,000 micron10 micron

EFFECT OF DROPLET SIZE (MICRONS) – TIME IT TAKES TO FALL 10 FEETAdapted from: Ross and Lembi, 1985. For illustrative purposes only.

28

hours

17

minutes

11

seconds

2

seconds

1

second

4

seconds

10 f

eet

Courtesy of Dr. Dan Reynolds

Relationship Between Drift and Efficacy

Efficacy

Drift reduction

Data Analysis

• Droplet size data were statistically analyzed using a full factorial response surface model

• Four main model factors along with potential interaction effects were evaluated

– Nozzle

– Application Volume Rate

– Orifice Size

– Formulation

• All possible factorial combinations of the four main factors were tested

• Percent fine droplets to relate to drift potential – Vol < 150 µm (%)

• Dv0.5 (VMD) relates to efficacy

Droplet Diameter ( m)

0 200 400 600 800 1000 1200 1400

Cum

ula

tive

Vo

lum

e (

%)

0

10

20

30

40

50

60

70

80

90

100

Dv10

Dv50 (VMD)

Dv90

V<100um

V<150um

V<250um

V<300um

How far will particles go?

Droplet Diameter

(in m)

Time to fall 10

ft

Travel distance in 3

mph wind

Fog 5 66 min 15,840 ft

Very fine 20 4.2 min 1,100 ft

Fine 100 10 sec 44 ft

Medium 240 6 sec 28 ft

Coarse 400 2 sec 8.5 ft

Fine rain 1,000 1 sec < 5 ft

Source: Herbicide Spray Drift, NDSU Extension

Spray Tank

Atomization

Impaction

Retention

Deposit Formation

Biological Effect

Chemical Reactions

Pump Shear

Equipment/Application

Mixing and Agitation

Physical Properties

Atmospheric Conditions

Evaporation

Micrometerological Effects

Spray and Surface Properties

Droplet Size and Kinetic Energy

Dynamic Spreading

Spreading and Coalescence

Absorption and Translocation

Surface Activity

Encounter ProbabilityPick-up and Transport to

the Site-of-Action

Equipment Contamination

Drift Losses

Interception by Non-targets

Redistribution

Reflection,

Shatter and

Splash

Losses

Losses

Redistribution

Redistribution

Run-off

Volatilization

Weathering

Loss of Active

Loss of DiluentVolatilization

Ebert et al. 1999

Field Studies

• Four locations in Nebraska– Bancroft, Clay Center, Courtland, Elba

• Four replications per location

• Five planted species– Amaranth, Flax, Velvetleaf, Soybean, Corn

• Five Nozzles plus an Untreated– XR11002 (Fine), XR11003 (Fine/Medium), TT11002 (Medium),

AIXR11002 (Coarse), AI11002 (Extremely Coarse)

Glyphosate

70

80

90

100

0 50 100 150 200 250

Eff

ica

cy (

%)

Droplet size (µm)

Amaranth

Fine

Fine/Medium

Medium

Coarse

Extremely Coarse

Clarity

55

65

75

85

0 100 200 300

Eff

ica

cy (

%)

Droplet size (µm)

Amaranth

Fine

Fine/Medium

Medium

Coarse

Extremely Coarse

Reflex

40

50

60

70

0 50 100 150 200 250

Eff

ica

cy (

%)

Droplet size (µm)

Amaranth

Fine

Fine/Medium

Medium

Coarse

Extremely Coarse

Reflex

65

75

85

95

0 50 100 150 200 250

Eff

ica

cy (

%)

Droplet size (µm)

Flax

Fine

Fine/Medium

Medium

Coarse

Extremely Coarse

Carrier Rate

• Herbicides

– Glyphosate (RoundUp PowerMax) – 3 GPA

– Glufosinate (Liberty) – 15 GPA

– Lactofen (Cobra) – 20 GPA

– 2,4-D (Weedone) – 10 GPA

• Plots

– 10’ x 30’

• Weed Control Ratings taken 14 and 28 DAT

Carrier Rate

• Soybean Management Field Day Locations

– Lexington, NE

– O’Neill, NE

– Platte Center, NE

– David City, NE

Materials and Methods

Carrier volume Nozzle

Applicationspeed

GPA mph

5 XR11001 4

7.5 XR11001 4

10 XR11001 4

15 XR110015 4

20 XR11002 4.8

Results

0

30

60

90

2,4-D Lactofen Glufosinate Glyphosate

Co

ntr

ol (

%)

Velvetleaf

47 L ha⁻¹

70 L ha⁻¹

94 L ha⁻¹

140 L ha⁻¹

187 L ha⁻¹

BBC B

C

A AA

A

C C

NS

NS

5 GPA7.5 GPA10 GPA15 GPA20 GPA

Results

5 GPA7.5 GPA10 GPA15 GPA20 GPA

Lactofen 5 GPA Lactofen 10 GPA

Amaranth

0 5 7.5 10 15 20GPA

0 5 7.5 10 15 20GPA

0 5 7.5 10 15 20 0 5 7.5 10 15 20

Experimental Design

• Randomized Complete Block Design with 4 Replications

• 10 inch tall Palmer amaranth

• 25 Total Treatments:

– 2 Carrier Volumes (5 and 20 GPA)

– 6 Droplet Sizes (150, 300, 450, 600, 750, and 900 µm)

– 2 Herbicides [dicamba (Clarity®) and glufosinate (Liberty®)]

– 1 Nontreated Control

• Applications were made using a Capstan PinPoint® Pulse-width Modulation (PWM) Sprayer

– This allows for flow to be controlled by the relative proportion of time each electronically actuated solenoid valve is open (duty cycle)1

– Duty cycle was demonstrated to have minimal impact on droplet size2,3

1Giles and Comino, 1989. J. of Commercial Vehicles. SAE Trans. 98:237-2492Butts et al., 2015. Proc. North Cent. Weed Sci. 70:111. Indianapolis, IN3Giles et al., 1996. Precision Agriculture. Proc. of the 3rd International Conference. 729-738. Minneapolis, MN

Droplet Size Determination Sympatec HELOS-VARIO/KR laser diffraction system

Herbicide Nozzle Pressure (kPa) Droplet Size (Dv50)

Lactofen (0.21 kg ai/ha) + COC (1% v/v)

ER110015 483 150 μm

SR11004 379 300 μm

MR11006 207 450 μm

DR11005 248 600 μm

UR11008 379 750 μm

UR11010 241 900 μm

Acifluorfen (0.42 kg ai/ha) + COC (1% v/v)

ER110015 414 150 μm

SR11004 324 300 μm

DR11003 414 450 μm

DR11006 331 600 μm

UR11006 345 750 μm

UR11010 276 900 μm

Lactofen – 7 DAT

300 μm 600 μm

Lactofen – 14 DAT

300 μm 600 μm

Lactofen – 28 DAT

300 μm 600 μm

300 μm 600 μm

Acifluorfen – 7 DAT

300 μm 600 μm

Acifluorfen – 14 DAT

300 μm 600 μm

Acifluorfen – 28 DAT

Palmer amaranth biomass - Lactofen

A

BC

C

BC

BC

B

C

0

20

40

60

80

100

120

140

160

180

Untreated 150 μm 300 μm 450 μm 600 μm 750 μm 900 μmDry

Palm

er a

mara

nth

bio

mass

(g)

*Columns followed by the same letter do not significantly differ according to Fisher Protected LSD (α=0.05)

Palmer amaranth biomass - Acifluorfen

A

B B

BAB

B

B

0

20

40

60

80

100

120

140

160

180

200

Untreated 150 μm 300 μm 450 μm 600 μm 750 μm 900 μm

Dry

Palm

er a

mara

nth

bio

mass

(g)

*Columns followed by the same letter do not significantly differ according to Fisher Protected LSD (α=0.05)

GAM Analysis

Max. weed control: 250 μm

90 % of Max. weed control: 180 – 310 μm

Deviance exp. = 53.3%

Nozzle type, orifice size, and application pressure combinations for each droplet size treatment.

Herbicide Carrier volume Droplet size Nozzle Application pressure

gal ac-1 µm PSI

glufosinate 5 150 ER 110015 60

glufosinate 5 300 SR 11005 40

glufosinate 5 450 DR 11004 40

glufosinate 5 600 UR 11004 35

glufosinate 5 750 UR 11008 40

glufosinate 5 900 UR 11010 30

glufosinate 20 150 ER 110015 50

glufosinate 20 300 SR 11003 30

glufosinate 20 450 MR 11006 35

glufosinate 20 600 DR 11008 39

glufosinate 20 750 UR 11006 33

glufosinate 20 900 UR 11010 36

Nozzle type, orifice size, and application pressure combinations for each droplet size treatment.

Herbicide Carrier volume Droplet size Nozzle Application pressuregal ac-1 µm PSI

dicamba 5 150 ER 110015 60

dicamba 5 300 ER 11006 42

dicamba 5 450 SR 11006 35

dicamba 5 600 DR 11004 34

dicamba 5 750 DR 11008 35

dicamba 5 900 UR 11006 40

dicamba 20 150 ER 110015 60

dicamba 20 300 SR 11002 30

dicamba 20 450 MR 11004 39

dicamba 20 600 DR 11005 52

dicamba 20 750 DR 11006 38

dicamba 20 900 UR 11006 35

Treatment Differences

• Glufosinate:

– For both carrier volumes, 750 and 900 µm droplets were not different from nontreated control for biomass reduction

• Dicamba:

– For both carrier volumes, 900 µm droplets were not different from nontreated control for biomass reduction

Carrier VolumeBest Droplet Size for Biomass Reduction

% Reduction in Biomass from

Control

Dicamba5 GPA 150 µm 80

20 GPA 600 µm 73

Glufosinate5 GPA 300 µm 93

20 GPA 450 µm 80

GAM Model for droplet size and carrier volume effect on Palmer amaranth control

57.5% Deviance Explained

5 GPA

20 GPA

Glufosinate

5 GPA

14 DAA

Control 150 µm 300 µm

450 µm 600 µm 750 µm 900 µm

28.0% Deviance Explained 5 GPA

20 GPA

GAM Model for droplet size and carrier volume effect on Palmer amaranth control

Dicamba

5 GPA

14 DAA

Control 150 µm 300 µm

450 µm 600 µm 750 µm 900 µm

Optimum droplet sizes for maximum Palmer amaranth

control

Dicamba Glufosinate

5 GPA 150 µm Fine 270 µm Medium

20 GPA 626 µmExtremely

Coarse488 µm Very Coarse

Questions?