SLIDE 1 Aerial Electrostatic Spray Deposition and Canopy Penetration in Cotton
Daniel E. Martin, Ph.D.
USDA‐ARS Aerial Application Technology Research Unit College Station, Texas
SLIDE 2 Electrostatic Deposition and Penetration
- Objective: Determine if electrostatically
charging an aerial spray could increase deposition and penetration of that spray in late season field cotton:
– DayGlo Rocket Red Dye – Mature Cotton Field – Spraying Water and 10% v/v Dye – Commercial Aerial Applicator – Air Tractor 301A
SLIDE 3
Rocket Red DayGlo Fluorescent Dye
SLIDE 4
Rocket Red DayGlo Fluorescent Dye
SLIDE 5
SLIDE 6
SLIDE 7
Electrostatic Nozzles
SLIDE 8
Electrostatic Deposition and Penetration
Anticipated Outcome: Scientific documentation of the deposition and penetration capabilities of the aerial electrostatic system.
SLIDE 9 Study Field Burleson County, Texas
165 Acres
SLIDE 10 Study Field
600’
SLIDE 11
SLIDE 12 Treatments
Treatment Nozzle Charge Application Rate (GPA) 1 Electrostatic Off 1.0 2 Electrostatic On 1.0 3 Rotary Atomizer Off 3.0 ‐ 60 Leaf samples from each treated area (10 Top Canopy, 10 Mid Canopy) ‐ 30 Water Sensitive Paper samples from each treated area
SLIDE 13
Field Application
SLIDE 14
Field Application Video
SLIDE 15
Field Application Video
SLIDE 16
Water Sensitive Papers
SLIDE 17
Leaf Processing
SLIDE 18
Leaf Processing
SLIDE 19
Fluorescent Imaging
SLIDE 20
Fluorescent Imaging
SLIDE 21
Leaf Area Measurements
SLIDE 22
Image Processing – Leaf Top
SLIDE 23
Image Processing – Leaf Bottom
SLIDE 24
Thresholded Image – Leaf Top
SLIDE 25
Selected Image– Leaf Top
SLIDE 26
Drawings – Leaf Top
SLIDE 27 Summary – Leaf Top
Slice Count Total Area Average Size %Area Mean T2R1T‐8T.JPG 3287 10276 3.126 0.028 26.76
SLIDE 28 Volumetric Median Diameter Water Sensitive Papers
203 202 210
Rotary Atomizer Charged No Charge
SLIDE 29 Application Rate Water Sensitive Papers
0.254 0.258 0.359
Rotary Atomizer Charged No Charge
SLIDE 30 Number of Droplets Water Sensitive Papers
220 239 358
Rotary Atomizer Charged No Charge
SLIDE 31 Droplet Density Water Sensitive Papers
11.4 12.4 18.5
Rotary Atomizer Charged No Charge
SLIDE 32 Droplet Density by Canopy
8.8 19.4 7.8 39.2 10.9 44.9
Charged No Charge Rotary Atomizer
Mid Top
SLIDE 33 Droplet Density – Top Canopy – Cotton Leaves
6.8 32.0 18.8 59.7 6.3 83.6
Rotary Atomizer Charged No Charge
SLIDE 34 Droplet Density – Mid Canopy – Cotton Leaves
1.7 15.7 1.9 13.5 1.5 20.4
No Charge Charged Rotary Atomizer
SLIDE 35 Conclusions
- DayGlo fluorescent dye is a very good tracer for
determining spray deposits in field cotton.
- The fluorescent imaging technique using ImageJ is a
very good and objective measure of spray deposits for both bottom and top leaf surfaces.
- Spray droplet density in the top of the cotton canopy
was higher than that of the mid canopy.
- Spray deposits on the top of the leaves was higher
than on the bottom of the leaves.
SLIDE 36 Conclusions
- Electrostatically charging the aerial spray increased
spray deposits on both leaf surfaces in the top canopy compared to the uncharged spray.
- All tested spray treatment resulted in equal canopy
penetration (mid canopy deposits).
- The electrostatically charged spray at 1 GPA had
equivalent top canopy top leaf deposits as the 3 GPA application.
- Charging the spray resulted in 3 times as many
deposits of the underside of the leaves compared to the uncharged and RA sprays.
