Effective Application Technology Management for Maximum Deposition and Coverage

Greg R. Kruger and Bradley K. Fritz

pat.unl.edu 2,4-D-resistant waterhemp

XR, Turbo TeeJet, and the TTI nozzle XR, Turbo TeeJet, and the TTI nozzle TT XR

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

1 micron 10 micron 100 micron 200 micron 400 micron 1,000 micron

28 17 11 4 2 1

hours minutes seconds seconds seconds second 10 feet 10

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 100 • Four main model factors along with 90 potential interaction effects were 80 evaluated 70 – Nozzle 60 – Application Volume Rate 50 40 Dv10 – Orifice Size Dv50 (VMD) 30 Dv90

Cumulative Volume (%) Volume Cumulative – Formulation V<100um 20 V<150um • All possible factorial combinations of V<250um 10 V<300um

the four main factors were tested 0 • Percent fine droplets to relate to drift 0 200 400 600 800 1000 1200 1400 potential – Vol < 150 µm (%) Droplet Diameter ( m)

• Dv0.5 (VMD) relates to efficacy How far will particles go?

Droplet Diameter Time to fall 10 Travel distance in 3 (in m) ft 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 Chemical Reactions Spray Tank Pump Shear Mixing and Agitation

Equipment Contamination Equipment/Application Atomization Physical Properties Drift Losses Atmospheric Conditions Interception by Non-targets Evaporation Volatilization Impaction Micrometerological Effects Redistribution Reflection, Shatter and Losses Spray and Surface Properties Splash Droplet Size and Kinetic Energy Retention Redistribution Run-off Dynamic Spreading Loss of Active Loss of Diluent Volatilization Spreading and Coalescence Deposit Formation Losses Weathering Absorption and Translocation Redistribution Surface Activity Pick-up and Transport to Encounter Probability Biological Effect the Site-of-Action

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

Amaranth 100

90 (%)

Fine 80 Fine/Medium Efficacy Efficacy Medium Coarse Extremely Coarse 70 0 50 100 150 200 250 Droplet size (µm) Clarity

Amaranth 85

75 (%)

Fine 65 Fine/Medium Efficacy Efficacy Medium Coarse Extremely Coarse 55 0 100 200 300 Droplet size (µm) Reflex Amaranth 70

60 (%)

Fine 50 Fine/Medium

Efficacy Efficacy Medium Coarse Extremely Coarse 40 0 50 100 150 200 250 Droplet size (µm) Reflex Flax 95

85 (%)

Fine 75 Fine/Medium

Efficacy Efficacy Medium Coarse Extremely Coarse 65 0 50 100 150 200 250 Droplet size (µm) 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 Application volume Nozzle speed GPA mph 5 XR11001 4 7.5 XR11001 4 10 XR11001 4 15 XR110015 4 20 XR11002 4.8 Results

Velvetleaf NS 90 A A A A

B B 60 NS BC 47 L ha⁻¹5 GPA C 70 L ha⁻¹7.5 GPA 94 L ha⁻¹10 GPA C C 140 L 15ha⁻¹ GPA

Control (%) Control 187 L 20ha⁻¹ GPA 30

0 2,4-D Lactofen Glufosinate Glyphosate Results

5 GPA 7.5 GPA 10 GPA 15 GPA 20 GPA Lactofen 5 GPA Lactofen 10 GPA 0 5 7.5 10 15 20 0 5 7.5 10 15 20

0 5 7.5 10 15 20 0 5 7.5 10 15 20 GPA GPA Amaranth 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. 98:237-249 2Butts et al., 2015. Proc. North Cent. Weed Sci. 70:111. Indianapolis, IN 3Giles 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) ER110015 483 150 μm SR11004 379 300 μm MR11006 207 450 μm Lactofen (0.21 kg ai/ha) + COC (1% v/v) DR11005 248 600 μm UR11008 379 750 μm UR11010 241 900 μm ER110015 414 150 μm SR11004 324 300 μm DR11003 414 450 μm Acifluorfen (0.42 kg ai/ha) + COC (1% v/v) 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 Acifluorfen – 7 DAT

300 μm 600 μm Acifluorfen – 14 DAT

300 μm 600 μm Acifluorfen – 28 DAT

300 μm 600 μm Palmer amaranth biomass - Lactofen

180

160 A

140

120 B 100 BC BC 80 BC C 60 C

40

20

0

Dry Palmer amaranth biomass(g) amaranth Palmer Dry Untreated 150 μm 300 μm 450 μm 600 μm 750 μm 900 μm

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

200 180 A 160 140 AB B B 120 B B B 100 80 60 40 20 Dry Palmer amaranth biomass(g) amaranth Palmer Dry 0 Untreated 150 μm 300 μm 450 μm 600 μm 750 μm 900 μm

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

Deviance exp. = 53.3%

Max. weed control: 250 μm 90 % of Max. weed control: 180 – 310 μm 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 pressure gal 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 % Reduction in TreatmentBest DifferencesDroplet Size for Carrier Volume Biomass from Biomass Reduction Control 5 GPA 150 µm 80 Dicamba 20 GPA 600 µm 73 5 GPA 300 µm 93 Glufosinate 20 GPA 450 µm 80

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

57.5% Deviance Explained

5 GPA 20 GPA Control 150 µm 300 µm Glufosinate

5 GPA

14 DAA

450 µm 600 µm 750 µm 900 µm GAM Model for droplet size and carrier volume effect on Palmer amaranth control

28.0% Deviance Explained 5 GPA 20 GPA Control 150 µm 300 µm Dicamba

5 GPA

14 DAA

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 Extremely 20 GPA 626 µm 488 µm Very Coarse Coarse Questions?