Spray

1. Optimization of spray application rates for plant canopies Spray Heping Zhu Agricultural Engineer , USDA ARS Randy Zondag OSU Lake County Extension Agent

2. How Much Do You Know About Your Sprayer ? • How much liquid it sprays • What type of coverage it gives • How far will it spray (distance) • What type of control will it give • OR

3. Does it Feel Like

4. Or Who’s Creek Are You Up ?

5. Or do I just Give Up?

6. 2 Different varieties and species

7. 3 Target varies – form, size, canopy structure and density

8. 4 Sprayers

9. 5 Adjust spray outputs

10. 6 Steps to optimize spray rates • Measure tree size and row spacing • Determine sprayer travel speed • Use Tree-Row Volume to estimate application rate • Use ribbons to help determine number of nozzles • Use calibration equation to determine nozzle flow rate

11. 6 Steps to optimize spray rates 6. Select nozzle tip size and operating pressure 7. Calibrate nozzles 8. Use water sensitive paper to verify spray coverage 9. Re-adjust application rate if necessary

12. 7 10 D H GPA = S Nursery Tree Row Volume 40 for orchards GPA - Application rate D - Tree width or diameter (ft) H - Canopy Height (ft) S - Distance between rows (ft)

13. 8 10x6.5x8 = 58 GPA = 9 Example Tree width: D=6.5 ft Canopy Height: H=11-3=8 ft Distance between rows: S=9 ft

14. 9 Three parameters to change sprayer output • Travel Speed • Nozzle size • Pressure

15. 10 Travel speed

16. Travel speed calibration • Setup an 88 ft long distance in a flat field • Measure the time that the sprayer travels the 88 ft distance • Use the following equation to calculate the speed

17. 60 V = T Where, V is the travel speed in miles per hour, and T is the time in seconds for the sprayer traveling the 88 ft distance. 4. Repeat steps 2 and 3 for three times and then take an average • 88 feet per minute is equal to one mile per hour

18. 12 43,560 Q GPA = 88 D V Calibration equations GPA – gallons/acre Q – sprayer total flow rate (gallon/min) D – spray width covered by each run (ft) V – travel speed (mph) N – number of nozzles If nozzles are same: Q = N x q If nozzles are different: Q = q1+ q2+ … + qN

19. 11 Use ribbons to estimate spray pattern to determine number of nozzles

20. 13 88 D V GPA 88x9x4x58 Q = = = 4.2 gpm 43,560 43560 Total flow rate from sprayer Single nozzle flow rate 4.2 q = = 0.6 gpm 7 No. of nozzles, N = 7 Spray width, D = 9 ft Speed, V = 4 mph GPA = 58

21. Nozzle selection 14 q = 0.6 gpm psi gpm

22. Nozzle calibration 15

24. 16 q = Cd2 P How does pressure affect output? Output (GPM) For example, a hollow cone nozzle D5-DC25 output is 0.35 GPM at 40 psi. 0.35 40 Pressure (psi)

25. 17 q = Cd2 P How does pressure affect output? Output (GPM) The output will be 0.48 GPM at 80 psi. 0.48 0.35 40 80 Pressure (psi)

26. 18 q = Cd2 P How does pressure affect output? Output (GPM) The output will be 0.6 GPM at 120 psi. 0.60 0.48 0.35 40 80 120 Pressure (psi)

27. 19 q = Cd2 P 0.70 0.60 0.48 0.35 40 80 120 160 Pressure (psi) How does pressure affect output? Output (GPM) The output will be 0.70 GPM at 160 psi.

28. 20 C A D B E Hand-held Pressure Gauge Calibrator • Calibrate pressure gauges • Remove test gauge (A) from sprayer. • Mount the gauge (A) to the test port (B) on calibrator. • Tighten knob (D) and squeeze handles (E) to pump air. • Compare pressure readings between two gauges (A, C). • If the gauge (A) is worn out, replace it. • However, if the gauge is only off line, mark the correct readings on the gauge and continue to use it.

29. Place water sensitive papers inside canopies 21

30. 23 Steps to optimize spray rates • Measure tree size and row spacing • Determine sprayer travel speed • Use Tree-Row Volume to estimate application rate • Use ribbons to help determine number of nozzles • Use calibration equation to determine nozzle flow rate • Select nozzle tip size and operating pressure • Calibrate nozzles • Use water sensitive paper to verify spray coverage • Re-adjust application rate if necessary

31. 22 “Reference” water sensitive paper images of over applied, sufficiently applied and under applied spray mixtures Over applied Sufficiently applied Under applied

32. Half Rate Pesticide Trial in Nursery Applications Sunleaf Nursery

33. Half Rate Pesticide Trial in Nursery Applications Willoway Nurseries

34. Half Rate Pesticide Trial in Nursery Applications Nursery spray trial Apple scab rating scale O= no disease 5= defoliated Banner Maxx 4 ounces per 100/gallons

35. 24 No differences were found between the half rate and full rate for either insect or disease control full rate half rate Crabapple

36. 25 Red maple half rate full rate

37. 26 Amelanchier half rate full rate

38. Droplets needed for control • Insecticides /pre emergence 130 droplets/inch 2 or 25 droplets cm2 • Post emergence herbicides 200 droplets inch2 or 35 droplets cm2 • Fungicides 330 droplets inch2 or 60 droplets cm2

39. Place water sensitive papers inside canopies 21

40. Application Technology Research Unit,USDA-ARS,Wooster,Ohio • Heping Zhu | agriculture engineer, USDA -ARS| • Contact Information : • Phone: (330) 263-3854FAX: (330) 263-3670E-Mail: Heping.Zhu@ARS.USDA.GOVWebsite(s): USDA • Address:203 Agricultural Engineering Building1680 Madison Avenue OARDCWooster, Ohio 44691

41. Deposit Scan Program Website DepositScan is a scanning program that can quickly evaluate spray deposit distribution on water sensitive paper or Kromekote® cards. http://ars.usda.gov/services/software/download.htm?softwareid=247

46. Spray Coverage on Water Sensitive Papers 25GPA 50GPA 75GPA 100GPA 7 ft above ground 5.5 ft above ground 4 ft above ground

47. DRIFTSIM, A Computer Program for Estimating Spray Drift Distances Spray drift

48. DRIFTSIM is a user-friendly computer program capable of predicting drift distances of spray droplets under a wide variety of conditions http://ars.usda.gov/services/software/download.htm?softwareid=252

49. DRIFTSIM, A Computer Program for Estimating Spray Drift Distances