Post on 11-Jun-2020
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?