Equipment, Calibration, and Tip Selection Considerations for the Application of Herbicides Robert E. Wolf Extension Specialist Application Technology Biological

Equipment, Calibration, and Tip Selection Considerations for the

Application of Herbicides

Robert E. WolfExtension Specialist Application Technology

Biological and Agricultural Engineering

Crop Protection Equipment and Calibration

Changes in the Application Industry!

Historically inefficient process Increased cost of pesticides Product rates are changing (< an ounce/acre) More pest specific products Biotechnology and GMO’s (Roundup Ready, Bt’s) More sophisticated equipment (electronics) $$$

Variable rates Site-specific Focus on Drift


Equipment today-$$$?


Sprayer Components:

Tanks (contamination issues) Pump, Strainers, Agitation Pressure gauge Hoses, Flow control assemblies Electronics: monitors-computers-

controllers (GPS/GIS) Distribution system Nozzles!!!!!!!!!


What about the cost of the nozzle?


Regardless of the cost:

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

Misapplication


Nozzles are important because: Control the amount – GPA. Determine uniformity of application. Affects the coverage. Influences the drift potential.


1. Control the Amount applied:

Nozzle Flow Rate is affected by:

Orifice size Pressure Solution

characteristics

Page 9 - TeeJet

Page 4 - Hypro



Page 4


Nozzle Selection Chart: Flat-fan

Page 7 - TeeJet


Rated Pressure =40 psi for most nozzle types10 psi for turbo flood nozzles

Nomenclature:

Stainless Steel Insert Orifice

Trade Name

Fan angle and flow rate-orifice size

Extended Range

VisiFlo Color Coding

(S,H,P,K,SS)


MATERIALS AND WEAR

0 2 4 6 8 10 12 14 16

Brass

Zytel

Stainless

Kematal

Hard Stainless

Thermoplastic

11.4

7.5

6.1

2.1

1.2

0.4

Percent increase in nozzle flow rateFlat-fan spray nozzles after 40 hour test


Typical nozzle numbering systemExtended-range

flat-fan

XR 11004 XR Extended-range

110 110 degree fan angle

04 0.4 GPM @ 40 psi

Even flat-fan –(Band applications)

8002E E Even spray pattern

80 80 degree fan angle

02 0.2 GPM @ 40 psi

Turbo flood -(small capacity)

TF- 4 TF Turbo flood

4 .4 GPM @ 10 psi

Turbo flood –(Floater capacity)

QCTF - 40

QCTF Quick attach turbo flood

40 4.0 GPM @ 10 psi


Calculations

GPA=

5940

#$!@&%!#$!@&%!


Calibration/Nozzle Selection

What is the first step? Use label to select the

application volumeproduct rate

Choose an appropriate travel speed Effective width of application

nozzle spacing Calculate GPM – Flow rate per nozzle Select the correct size of nozzle!


Calculations

GPA=

5940

Ok, now I remember!Ok, now I

remember!


Flow Rate Equation

GPMGPA x MPH x W

5940

Equation # 2

Calculates for amount of flow from one nozzle

Represents the size of nozzle to put on the sprayer

Calculates for amount of flow from one nozzle

Represents the size of nozzle to put on the sprayer


GPM Example Solution

GPMGPA x MPH x W

5940

5940

20x12x12GPM

Answer.48


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

Selecting the proper nozzle….

.48

Page 7


Electronics/Rate Controllers

How does your system work when speed changes?

Is it pressure based? What is the effect of

going slower? What is the effect of

going faster?



Checking for accuracy!!!


MEASURE SPEED

Speed(MPH)Distance(ft) x 60

Time(seconds) x 88

(1 MPH = 88 Feet traveled in 60 seconds)

Measure the ground speed in an area similar to the conditions of the area to be sprayed!


2. Set up for Uniformity

Goal is to put the material on evenly from nozzle to nozzle, end of boom to end of boom, and across the entire field.

20-inch spacing requires 17-19” above target for 50-60% overlap.


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


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?


Why Interest in Drift? Spotty pest control Wasted chemicals Off-target damage More high value specialty crops Urban sprawl and..... Less tolerant neighbors Litigious Society More wind?? (Timing) Environmental impact

Water and Air Quality Public more aware of pesticide

concerns! (Negative Perceptions) Result-higher costs-$$$


Spray Characteristics are Important to Understand:

Demonstrates Turbo Flat vs TurboDrop-5 MPH Wind


Nozzle Technology? How to use??

Nozzles designed to reduce drift Improved drop size control Emphasis on ‘Spray Quality’


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

110°

80°


Turbo Flood Nozzle vs Old Style Flood

Pre-orifice design Turbulence chamber Uniform spray distribution with

tapered edge – 50-60% overlap Large, drift resistant droplets

TF

Flood


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

XR

TT


XR Flat-fan compared to Turbo Flat-fan in 5 MPH wind:

40 psi


Air-Induction/Venturi Nozzles Where air is drawn into the nozzle

cavity and exits with the fluid.


Air/Induction – Venturi Nozzle:

Greenleaf – TurboDrop Air intake venturi section Mixing Chamber - air and

spray solution blended Pattern tip forms large air-

bubble drops Exit tip flow 2X venturi

orifice Better Penetration? Reduced run-off? Improved coverage? Adequate efficacy? Reduced drift?


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


Driftable Droplets: Spraying Systems-2000

Nozzle Type(0.5 GPM Flow)

Approximate % of Spray

Volume < 200 Microns

15 PSI 40 PSI

XR 11005 14% 22%

XR 8005 6% 12%

DG 11005 N/A 11%

DG 8005 N/A 7%

TT 11005 <1% <6%

TF-2.5 <1% <1%

AI 11005 N/A <1%


XR Flat-fan @20, 40, 80 PSI Turbodrop XL @20, 40, 80 PSI

Boom

Drift


Example Reference Graph

Cumulative Volume Fraction

0.1 0.5 0.9

Drop S

ize (microns) 0

100

200

300

400

500

600

700

800

900

very fine/ fine fine/mediummedium/ coarsecoarse/ very coarsevery coarse/ extremely coarse

VF

F

M

CVC

XC

New Label language-EPA Reviewing Public Comments

Public ‘Listening Sessions’ planned

Sometime in 2003?? Match the crop

protection product to the target

Adhere to label guidelines based on an industry standard ASAE S-572

Buffer Zones or No Spray Zones

Maximize Efficacy Minimize Drift

EPA Requested Changes Coming!!!!

Example Reference Graph

Cumulative Volume Fraction

0.1 0.5 0.9

Dro

p S

ize

(mic

rons

)

0

100

200

300

400

500

600

700

800

900

very fine/ fine fine/mediummedium/ coarsecoarse/ very coarsevery coarse/ extremely coarse

VF

F

M

CVC

XC


ASAE DSC and Volume Median Diameter (DV0.5) From PMS* Laser Spectrometer

Very Fine (VF) < 182µm Fine (F) 183-280µm Medium (M) 281-429µm Coarse (C) 430-531µm Very Coarse (VC) 532-655µm Extremely Coarse (XC) >656µm

*USDA ARS College Station, TX

Droplet Spectra Classification (DSC)

Droplet SizeRange



Important Droplet Statistics:

Operational Area


Application Decisions?


For more information contact:

www.bae.ksu.edu/rewolf/

[email protected]

Documents

Equipment, Calibration, and Tip Selection Considerations for the Application of Herbicides Robert E. Wolf Extension Specialist Application Technology Biological