Nozzle Selection Basics for Private Applicators

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Nozzle Selection Basics for Private Applicators

• David Nicolai
• Regional Extension Educator-Crops Hutchinson, MN

Credit to Robert E. Wolf, Extension Specialist
Application Technology, Kansas State University
Robert N. Klein, Extension Cropping Systems
Specialist, University of Nebraska.
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Regardless of the status of existing nozzles
consider that

• Without proper attention to the nozzle, you may
  end up with a misapplication

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Nozzles are important to the Private Applicator
because they

• Control the amount GPA.
• Determine uniformity of application.
• Affects the coverage.
• Influences the drift potential.

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Broadcast Crop Spray Nozzle choices are numerous
but often are targeted to a specific crop canopy,
pest or drift mgt situation.Which one is the
best?

• Flat Spray Tips
• Extended Range Flat-fan
• Drift Reduction Flat-fan
• Turbo Flood Flat-fan
• Turbo Flat-fan
• AI Flat-fan
• TurboDrop

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What Coverage is Needed?

• Need knowledge of the product being used.
• Systemic
• Contact
• What is the target?
• Soil
• Grass
• Broadleaf (smooth, hairy, waxy)
• Leaf orientation time of day
• Disease prevention
• Insect

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Selecting the proper nozzle

• Legal issues!!
• Following the label!

Refer to the label and nozzle manufactures
catalog for initial guidance
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Nozzle Selection Basics

• What is the first step?
• Use label to select the
• application volume
• product rate
• Choose an appropriate travel speed
• Effective width of application
• nozzle spacing
• Calculate GPM Flow rate per nozzle
• Select the correct size of nozzle!

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Flow Rate Equation
GPA x MPH x W
GPM
5940

• Calculates for amount of flow from one nozzle
• Represents the size of nozzle to put on the
  sprayer

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GPM Example Solution
GPA x MPH x W
GPM
5940
12 x 12 x 20
GPM
5940
0.48
Answer
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Selecting the proper nozzle.
GPA

• Calculate GPM (formula)
• Look under GPM column
• Match to pressure-psi
• Choose the size needed
• Operate at given pressure and speed used in
  formula to achieve GPA

0.48
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Factors that control the Amount applied

• Nozzle Flow Rate is affected by
• Orifice size
• Pressure
• Solution characteristics

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Typical Nozzle Numbering System Example
Extended Range
Trade Name
(S,H,P,K,SS)
Stainless Steel Insert Orifice
VisiFlo Color Coding
Fan angle and flow rate-orifice size(110 degree
angle at .04 GPM)
Rated Pressure
40 psi for most nozzle types 10 psi for turbo
flood nozzles
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Consider drift potential when selecting nozzles
because

• Spotty pest control
• Wasted chemicals
• Off-target damage
• More high value specialty crops
• Urban sprawl and.....
• Less tolerant neighbors
• Litigious Society
• Organic Certification requires fields to be
  pesticide-free for 3 years
• Environmental impact
• Public more aware of pesticide
• concerns! (Negative) (Perceptions)
• Result-higher costs-

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Factors Affecting Drift

• Spray Characteristics
• chemical
• formulation
• drop size
• evaporation

• Equipment Application
• nozzle type
• nozzle size
• nozzle pressure
• height of release

• Weather
• air movement (direction and velocity)
• temperature and humidity
• air stability/inversions
• topography

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Nozzle Droplet size measured in microns
VMD
(Volume Median Diameter)
One micron (?m) 1/25,000 inch
(average human hair 90 ?m)
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1/2 of spray volume smaller droplets 1/2 of
spray volume larger droplets
VMD
Volume Median Diameter is defined as 50 of the
volume of the spray is smaller than the size
shown
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Efficacy and Drift Mitigation

• Size of the Spray Droplets - Microns
• Volume Median Diameter (VMD)
• Droplet Spectrum (Range - big to small)

Volume in droplets less than 200 microns in
size are highly driftable.
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Effect of Droplet Discharge Height and Wind
Velocity on Drift Distances of Various Size
Droplets Discharged Downward at 44 mphH.E. Ozkan
Ohio State
Droplet completely evaporated before deposition
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lt150
151-250
251-350
351-450
451-550
gt551
Source Crop Life July 2002
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Spraying Systems Droplet Size in Microns
Category Very Fine Fine Medium Coarse Very
Coarse Extensively Coarse
?m size range 153 and less 154 241 242 -
358 359 - 451 452 - 740 741
Spray System Fungicides just into this
class Non-Translocated Herbicides Translocated
Herbicides Preplant, Preemergence Herbicides
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In Conclusion
Minimizing spray drift is in the best interests
of everyone. Do your part to keep applications
on target.