Comparison of Drift Potential for Venturi, Extended Range, and Turbo Flat-fan Nozzles

1. Comparison of Drift Potential for Venturi, Extended Range, and Turbo Flat-fan Nozzles Robert Wolf Biological and Agricultural Engineering Dept. Cathy Minihan Department of Agronomy

2. Nozzle is still an important part of the application process! • Determines the application rate • Determines the uniformity • Determines the coverage • Determines the drift potential

3. Will determine coverage: • Need knowledge of the product being used. • Systemic • Contact • What is the target? • Soil • Grass • Broadleaf (smooth, hairy, waxy) • Leaf orientation – time of day

4. Will affect drift: • Movement of spray particles off-target. • Creating smaller spray drops will result in increased drift. • Is it Coverage vs Drift? • What is the answer? $64,000 Question?

5. Efficacy and Drift Potential is Influenced by: • Size of the Spray Droplets - Volume Median Diameter (VMD) • Droplet Spectrum (Range - big to small) % Volume or Number of droplets less than 200 microns in size

6. Nozzle Technology Today? • Nozzles designed to reduce drift • Improved drop size control • Emphasis on ‘Spray Quality’

7. Extended Range Flat-fan: • Tapered edge pattern • 80 and 110 degree fan • Requires overlap - 50 to 60% • 15-60 psi range 80° 110°

8. Turbo Flat-fan • Turbulence chamber as in the Turbo Flood • Tapered edge, wide angle flat pattern • Designed to work in flat-fan nozzle holder • Uniform spray distribution, 50-60% overlap • Wide pressure range, 15 – 90 psi • Large, drift resistant droplets • Plastic with superior wear characteristics TT XR

9. Air/Induction – Venturi Nozzle: • Greenleaf – TurboDrop • Air intake venturi section • Mixing Chamber - air and spray solution blended • Pattern tip forms large air-bubble drops • Required Exit tip flow 2X venturi orifice • Better Penetration? • Reduced run-off? • Improved coverage? • Adequate efficacy? • Reduced drift?

10. XR Flat-fan and Turbo Flat-fan compared to Venturi Style Nozzle5.0 MPH wind at 40 psi XR vs TurboDrop Turbo Flat vs Turbo Drop

11. 1/2 of spray volume = smaller droplets VMD 1/2 of spray volume = larger droplets

12. Objective of this study: • Field measure the spray droplet characteristics to evaluate the drift potential of a venturi flat-fan nozzle compared to extended range and turbo flat-fan nozzles.

13. Materials and Methods: Experiments: Exp. 1 and 2 Early and Late Postemergence Grass Exp. 3 and 4 Early and Late Postemergence Broadleaves Location: Manhattan, KS Exp. Design: 2 x 3 x 3 factorial with 4 reps Plot Size: 3 x 9 m with 1.5 m buffer Crop Oats ‘Don’(Exp. 1 and 2) Weeds Velvetleaf, pigweed, and morning glory (Exp. 3 and 4) Visual Ratings: 1, 2, and 4 weeks after treatment Herbicides (2): Paraquat, 0.14 kg/ha Glyphosate, 0.23 kg/ha Application Conditions: Exp. 1Exp. 2Exp. 3Exp. 4 Date: April 19, 2000 May 5, 2000 Aug. 18, 2000 Sept. 1, 2000 Oat/weed Size: 15 cm 51 cm 10 cm 21 cm Temperature: 20 C 25 C 21 C 24C R. H.: 50% 56% 75% 71% Wind: W-NW 8-10 km/h SE 5-8 km/h NE 11-19 km/h N-E 3-10 km/h

14. Materials and Methods cont.: Spray Tips (3): Extended Range Flat-fan (XR) Turbo Flat-fan (TT) Air Induction Flat-fan (AI) Spray Volumes (3): 47 L/ha (110015 orifice tips) 94 L/ha (11003 orifice tips) 187 L/ha (11006 orifice tips) Application Ground Speed: 10 km/h Spray Pressure: 276 kPa Spray Tip Spacing: 76 cm Canopy Boom Height: 51 cm

15. DropletScan used to analyze droplets: Water Sensitive Paper Software & lock-key Color Scanner Portable computer Color Printer System Components

16. What is DropletScan ? • A software program that will allow accurate and rapid measure of spray droplet impressions on water-sensitive paper. • Developed at K-State by Devore Systems - modeled after ‘Crumbscan’, a software program to determine hole sizes in slices of bread.

17. Important Droplet Statistics: • Dv0.1 (µm) - 10% of the spray volume in drops < number reported • Dv0.5 (µm) - 50% of the spray volume in drops < number reported (also is VMD- volume median diameter) • Dv0.9 (µm) - 90% of the spray volume in drops < number reported • Number of droplets under 200 microns

18. Important Droplet Statistics: VMD (50%) Operational Area VD0.9 (90%) VD0.1 (10%)

19. Collection Procedure:

20. Sample cards: XR TT AI 10 GPA XR TT AI 5 GPA XR TT AI All at 40 PSI 20 GPA

21. Results and Discussion

22. All Treatments – Number of Droplets < 200 Microns 5 GPA 20 GPA 10 GPA

23. Orifice Size Affect – Number of Droplets < 200 Microns

24. Summary of Findings - Droplet Count under 200 microns: • At 47 L/ha the extended range flat-fans nearly doubled the turbo flat-fans and created more than four times the venturi flat-fans number of droplets less than 200 microns in size. • At 94 L/ha the extended range flat-fans again nearly doubled the turbo flat-fans and more than tripled the venturi flat-fans for number of droplets created under 200 microns.

25. Summary of Findings - Droplet Count under 200 microns: • At 187 L/ha the differences showed similar trends but were not nearly as pronounced. • Increasing the application volumes for each nozzle type by increasing the nozzle orifice size also reduced the number of driftable droplets. • Venturi nozzle designs reduce the number of droplets created under 200 microns in size when compared to extended range and turbo flat-fan nozzle styles.

26. XR Flat-fan and Turbo Flat-fan compared to Venturi Style Nozzle5.0 MPH wind at 40 psi XR vs TurboDrop Turbo Flat vs Turbo Drop

27. Thanks