SPRAYER ACCURACY July 2003

Objective of Calibration Determine the volume or weight that application equipment will apply to a known area under a given set of conditions.

VOLUME OF PESTICIDE SOLUTION APPLIED DEPENDS UPON: NOZZLES PRESSURE SPEED Spacing of Nozzles Viscosity of liquid WHY CALIBRATE??

1984 Colorado Spray Check Program

TeeJet nozzle examples

Hypro Nozzles

NOZZLE TIP DESIGNATIONS SPRAYING SYSTEMS CO. HSS8002E HSS 80 02 E HSS = HARDENED STAINLESS STEEL 80 = 80 DEGREE SPRAY ANGLE 02 = 0.2 GALLON PER MINUTE AT 40 PSI E = EVEN FLAT FAN PATTERN FOR BAND APPLICATION

HOW TO CHOOSE THE RIGHT NOZZLE SIZE GPM = GPA x MPH x Nozzle spacing in inches 5940 GPM = Gallons per minute per nozzle GPA = Gallons per acre MPH = Miles per hour

EXAMPLE GPA = 30 MPH = 4 Nozzle spacing = 20 GPM = 30 GPA x 4 MPH x 20 in 5940 GPM = 0.40

Find nozzle capacity in GPM in manufacture's catalog. Desired spraying pressure = 40 psi Using Spraying Systems catalog an 8004 nozzle would work the best.

TeeJet Standard Flat Spray Tips GPA - 20 inch spacing

Rule of Thumb An 8004 nozzle will deliver 40 gpa when used at 3 mph with 40 psi. Likewise an 8002 will deliver 20 gpa under the same conditions. An 8001 will deliver 10 gpa.

HOW TO CHANGE SPRAYER OUTPUT NOZZLES Best for large changes in output

HOW TO CHANGE SPRAYER OUTPUT Pressure Only feasible within a limited pressure range Pressure must be increased by a factor of 4 in order to double the flow 10 GPA at 20 PSI 20 GPA at 80 PSI

HOW TO CHANGE SPRAYER OUTPUT SPEED Only feasible within a limited range of speeds Double ground speed will decrease output by 50% 1/2 ground speed will increase output by 50%

MAXIMIZING SPRAYER PERFORMANCE NOZZLES Nozzle types Flat fan is best for broadcast application of herbicides Flat fan Even fan

MAXIMIZING SPRAYER PERFORMANCE

MAXIMIZING SPRAYER PERFORMANCE

MAXIMIZING SPRAYER PERFORMANCE

BOOM BUSTER SPRAY NOZZLES THAT WORK WITHOUT BOOMS FEATURES All nozzles machined from solid stainless steel.  All have replaceable industrial grade nylon diffusers. (Tests have shown that this nylon will outlast stainless steel.)

Boom Buster (con’t) Extra wide spray pattern. Excellent pattern and distribution. All models spray chemicals and fertilizers. All nozzles have standard pipe threads.

Boom Buster (con’t) USES Row Crops, Grain and Pastures State and County Right-of-Ways Orchards and Vineyards Forestry and Utility Right-of-Ways Lawn and Turf Roads, Hedge Rows and Fence Rows

MAXIMIZING SPRAYER PERFORMANCE Nozzle uniformity Nozzle types and orifice sizes must be the same across the boom

MAXIMIZING SPRAYER PERFORMANCE Nozzle orientation Directed straight down toward the ground and angled 5 to 10 degrees from parallel to the boom to prevent collision of spray droplets from adjacent patterns

MAXIMIZING SPRAYER PERFORMANCE Nozzle materials Stainless steel, brass and polymer are the most common. Stainless steel is probably the best choice

RELATIVE NOZZLE WEAR

MAXIMIZING SPRAYER PERFORMANCE Screens and filters Use appropriate screens and filters 0.2 GPM or more use 50 mesh Less than 0.2 GPM use 100 mesh

Spray Drift Management

Misapplication Facts Source: Farmland Insurance 1996 July 2003 3

Contributions to Drift July 2003 3

Relationship of Drift to Drop Size Particle drift results by creating smaller drops. Spray droplets are measured in microns and expressed as Volume Median Diameter (VMD). One micron (m) =1/25,000 inch July 2003

Comparison of Micron Sizes for Various Items (approximate) #2 Pencil lead paper clip staple toothbrush bristle sewing thread human hair 150 July 2003

Droplet Size Large droplets have less potential to drift because they: Fall more quickly Evaporate more slowly Are less affected by wind Small droplets often result from: High spray pressure Small nozzle tips Wind shear across the nozzles

Drift Potential is Influenced by Volume Median Diameter (VMD) 50% Droplet Spectrum (Range - big to small) % Volume in droplets less than 200 microns in size July 2003

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

Cutting Droplet Size in Half Results in Eight Times the Number of Droplets 250 Microns 250 Microns 500 Microns 250 Microns 250 Microns 250 Microns 250 Microns 250 Microns 250 Microns

Cutting Droplet Size in Half Results in Eight Times the Number of Droplets Cutting Droplet Size in Half = 500 Microns 250 Microns 2 more droplets fill in the sphere

Evaporation and Deceleration of Various Size Droplets* Terminal Final Drop Time to Deceleration Diameter Velocity diameter evaporate distance (microns) (ft/sec) (microns) (sec) (in) 20 .04 7 0.3 <1 50 .25 17 1.8 3 100 .91 33 7 9 150 1.7 50 16 16 200 2.4 67 29 25 *Conditions assumed: 90 F, 36% R.H., 25 psi., 3.75% pesticide solution July 2003

Low Drift Nozzle Types Flat-fan(Spraying Systems, Hardi, Delavan, Lurmark, others) Raindrop (Delavan) Drift Reduction Flat-fan (Several) July 2003

Low Drift Nozzle Types, cont: Turbo Flood (Spraying Systems) Turbo Flat-fan (Spraying Systems) TurboDrop AI Flat-fan SprayMaster Ultra Compact Venturi

Dropsize Comparisons (Data provided by Spraying Systems Co.) Could we add a chart using Erdal’s or Green Leaf’s data on the Turbo Drop comparison to conventional? *Numbers listed are in Microns (Dv.5) July 2003

Nozzle Dropsize Classification Selection based on droplet size: Very Fine Fine Medium Coarse Very Coarse <119 m 119-216 m 217-353 m 354-464 m >464 m Insecticides and Fungicides Herbicides Postemergence Soil Applications of Herbicides July 2003

Air Inclusion Just air pressure, or both air and liquid pressure used to atomize and carry the spray solution to the target. Sprayer operator can vary droplet size independently of nozzle flow rate.

Air Atomizers AirJet Shear Guard Plus (Spraying Systems Co., Illinois) (Spray-air USA inc., Idaho)

AirJet Atomizer--- Flow rate vs. Droplet size

Air Inclusion Technology "Air Inclusion technology over last five years, has done more to reduce off target trespass than any other technology that I am aware of, past or present. This technology has come to the market and has been widely adopted without mandated regulation. It has been a voluntary effort by manufacturers, researchers, growers, and retailers to develop and promote low-drift application practices which are in the best interest for agriculture." Thomas M. Wolf, PhD

Droplet Dynamics

20 psi 40 psi 75 psi TeeJet XR Hypro TR Hypro ULD Air Bubble Jet TurboDrop Delavan Ultra 20 psi 40 psi 75 psi

Droplet Speed At tip: all droplets: (43mph) 20 inches below tip: Large droplets: (17mph) Small droplets: (4.3 mph)

Droplet Direction Large droplets: combination of nozzle and travel direction e.g. (18 mph)  , (6 mph)  Small droplets: whichever way the wind is blowing

Droplets in a Grass Canopy Large droplets Small droplets Interception Interception Penetration

If I use lower Water Volumes, what are my nozzle choices?

Glyphosate on Tame Oats 100 90 4 gpa 80 70 Avena control (%) 60 12 gpa 50 8 gpa 40 30 200 300 400 500 600 Volume Median Diameter (µm)

Glyphosate on Oriental Mustard 100 4 gpa 90 80 70 Brassica control (%) 60 12 gpa 50 8 gpa 40 30 200 300 400 500 600 Volume Median Diameter (µm)

13.36 GPA 9.09 GPA 4.81GPA

Is Boom Height important?

Droplet Size Within Spray Pattern Droplet Number

MAXIMIZING SPRAYER PERFORMANCE

Spray Height Chart Use this slide to demonstrate where the numbers from the previous slide came from, and to point out that the Spray Parts Guide contains charts like this.

MAXIMIZING SPRAYER PERFORMANCE BOOM HEIGHT Rule-of-thumb when using 80 degree tips Set the boom above the target by whatever the distance is between nozzles If nozzle spacing is 20" then set boom 20" above target

MAXIMIZING SPRAYER PERFORMANCE Nozzle placement Need to be placed for proper overlap. Flat fan nozzles should overlap 30%.

Boom Height and Overlap Droplet Number 30 % Overlap

Boom Height and Overlap Droplet Number 100 % Overlap

Strategies to Reduce Drift Select nozzle to increase drop size. Increase flow rates - higher application volumes. Use lower pressures. Use lower spray (boom) heights. Avoid adverse weather conditions. Consider using buffer zones. Consider using new technologies: drift reduction nozzles drift reduction additives shields, electrostatics, air-assist

Spraying Accuracy

MAXIMIZING SPRAYER PERFORMANCE

Cooperative Extension Service University of Wyoming Cooperative Extension Service