1. Comparison of Spray Droplet Characteristics for Nozzles Used for Agronomic Weed Control Robert Wolf Cory Friedli and Brian Lauer Biological and Agricultural Engineering Dept.

2. Nozzle Efficacy/Drift Slope Extended Range Chamber Design Venturi Design - I Venturi Design - II XR, TR Turbo Flood Turbo TeeJet Air Mix AI XR GuardianAir AI Ultra Low Drift Turbo Drop TTI Nozzle development timeline

3. New 2008 Test Nozzles! Turbo TwinJet AI XR TeeJet Air Mix & TDHSTF- Greenleaf GuardianAir - Hypro

5. Objective The objective of this study was to compare droplet spectra characteristics for nozzle types used to apply postemergence herbicides.

6. Materials and Methods cont.: 24 ft. spray bar 7.5 GPA @ 10 MPH 0.24 GPM / nozzle Nozzle Spacing: 20 in. Boom Height:20 in.

7. 1. XR Flat-fan (XR) 5. AIC Venturi Flat-fan 6. TurboDrop High Speed Twin-fan 7. Ultra Lo Drift (ULD) 8. TTI Venturi Flat-fan Materials and Methods cont.: 2. DR Flat-fan DR 3. Turbo Flat-fan (TT) 4. Turbo Twin Flat-fan (TTJ60) 9. BFS Venturi Flat-fan 10. AIXR Venturi Flat-fan (AIXR) 11. Air Mix Venturi Flat-fan (AM) 12. GuardianAir Venturi Flat-fan (GA)

9. Discussion Results

10. DropletScan  used to analyze droplets  Droplet scan software was used for droplet characteristics Volume Median Diameter, Percent Area Coverage, Deposition  Statistical analysis with SAS

11. Droplet Size b a ef cd f dbc cdd dc

12. Coverge cd bc de b f cd a a bc c cde

13. Deposition b bb b bb b b b b b b

17. Findings Statistical differences were found for all droplet characteristics measured. TTI - largest droplets, with lowest coverage and deposition. XR - smallest droplets, with most coverage and deposition. ULD – middle on droplet size, 2 nd best coverage and deposition. Venturi design II group as an average had smaller droplets, better coverage and deposition than the venturi design I group.

18. Conclusions: The findings support that the use of nozzle types producing smaller droplets tend to have more coverage and deposition than those producing larger droplets. Data also supports that the newer designs in venturi nozzles will provide more coverage and deposition than the older venturi nozzle designs.

19. T hanks