volume median diameters from a medium spray quality nozzle

Volume Median Diameters from a Medium Spray Quality Nozzle

150

200

250

300

350

VMD,µm

Water Agral Ethokem L1-700 Axiom Codacide Silwet L-77

Spray liquid

Spray Volume in Small Droplets from a Medium Spray Quality Nozzle

0

5

10

15

20

% sprayvolume

<100 µm

Water Agral Ethokem L1-700 Axiom Codacide Silwet L-77

Spray liquid

Polymers

Used as drift control adjuvants/ deposition aids Hundreds of products but only a few chemistries Need to be sure of compatibility with nozzle type

being used and tank mix partners - tests with water may not be representative

Many polymers increase VMD but also increase fines - need to look at entire droplet size spectrum

Many polymers break down when pumped giving change in performance over time

Transition From Spraying Water (Right) to 0.35 % Polyacrylamide Through Flat Fan Nozzle

Transition From Spraying Water (Right) to 0.35 % Polyacrylamide Through Disc-Core Nozzle

Transition From Spraying Water (Right) to 0.35 % Polyacrylamide Through Full Cone Nozzle

Roundup, flat fan

Polymer, flat fan

Pumped Polymer, flat fan

Fertilizer Effects

Some suggestions that fertilizers increase drift potential

Probably actually increase drift damage rather than drift exposure risk

Literature reports on increased activity of glyphosate with ammonium sulfate

SDTF conducted atomization tests showing no effect on droplet size spectra

Figure 2. Atomization of Garlon 3A+Activator 90 Through CP0.125 With 30° Deflector, With and Without Uran at 60 and 120 mph Flight Speeds

0

10

20

30

40

50

60

70

80

90

100

0.0 250.0 500.0 750.0 1000.0 1250.0 1500.0

Upper Diameter of Droplet Size Class (µm)

Cu

mu

lati

ve

Sp

ray

Vo

lum

e (

%)

Garlon, 60 mph Garlon, 120 mph Garlon + Uran, 60 mph Garlon + Uran, 120 mph

Figure 1. Atomization of Roundup Through CP0.125 With 30° Deflector, With and Without Uran at 60 and 120 mph Flight Speeds

0

10

20

30

40

50

60

70

80

90

100

0.0 250.0 500.0 750.0 1000.0 1250.0 1500.0

Upper Diameter of Droplet Size Class (µm)

Cu

mu

lati

ve S

pra

y V

olu

me

(%

)

Roundup, 60 mph Roundup, 120 mph Roundup+Uran, 60 mph Roundup+Uran, 120 mph

Figure 3. Atomization of Orthene 75S+Crop Oil Concentrate Through CP0.125 With 30° Deflector, With and Without Uran at 60 and 120 mph Flight Speeds

0

10

20

30

40

50

60

70

80

90

100

0.0 250.0 500.0 750.0 1000.0 1250.0 1500.0

Upper Diameter of Droplet Size Class (µm)

Cu

mu

lati

ve

Sp

ray

Vo

lum

e (

%)

Orthene, 60 mph Orthene, 120 mph Orthene + Uran, 60 mph Orthene + Uran, 120 mph

Figure 4. Atomization of Roundup Through D8 Nozzle, With and Without Uran at 60 and 120 mph Flight Speeds

0

10

20

30

40

50

60

70

80

90

100

0.0 250.0 500.0 750.0 1000.0 1250.0 1500.0

Upper Diameter of Droplet Size Class (µm)

Cu

mu

lati

ve

Sp

ray

Vo

lum

e (

%)

Roundup, 60 mph Roundup, 120 mph Roundup + Uran, 60 mph Roundup + Uran, 120 mph

Conclusions Formulation effects on nozzle performance are

important, influencing atomization, retention, efficacy and spray transport/ drift

Entire tank mix, not a.i. or formulation type, affects drift potential

Entire droplet size spectrum (especially “fine” end) important, not only VMD

Surfactants and crop oils have varying effects

Emulsions may improve spray pattern and increase droplet size

Conclusions Some polymers broken down by pumping Fertilizers have little effect on atomization Some new nozzle designs may be more sensitive

to formulation effects Other effects: encapsulation, evaporation

retardants, etc