Calibrating Spray Calibrating Spray EquipmentEquipment

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Why CalibrateWhy Calibrate

• Better Pest Control• Environmental and human safety• Effective use of time

– Inadequate control = more treatments• Cost/Benefit ratio

– Lack of calibration = improper mixing– 1 gallon of Tordon per 100 gallons of water

• Will revisit

What’s An Application What’s An Application RateRate

• Gallons of liquid applied per acre• GPA• Water and pesticide mixed• a.k.a.

– Sprayer volume– Sprayer output

• Need to know GPA for mixing

Variables Affecting GPAVariables Affecting GPA

• Ground Speed (MPH)– Speed up = less liquid = lower application rate – Slow down = more liquid = increased application rate

Consistency

Variables Affecting GPAVariables Affecting GPA

• Nozzle Flow Rate– GPM– Depends on

Orifice size

= 0.50 GPM

= 0.20 GPM

Variables Affecting Variables Affecting GPAGPA

• Pressure– 4x pressure to double GPA– Increased pressure = smaller droplets

For Minor Adjustments Only

Variables Affecting GPAVariables Affecting GPA• Spray Width or Spacing

– 100% swath overlapping doubles output

Variables Affecting GPAVariables Affecting GPA

• Nozzle Wear– Worn tips =

• Over application• Erratic patterns

• Label requirements

Figuring Out Figuring Out GPAGPA

More GPA = More Coverage

• Label requirements

Figuring Out GPAFiguring Out GPA

• Determine Your Field Speed

– Know it to maintain it!

200 Feet in 27 seconds20

027= 5 MPH

X 0.682

Buy a Buy a speed speed sensorsensor

• Label requirements• Determine Your Field Speed

Figuring Out Figuring Out GPAGPA

• Collect from each nozzle

- Find GPM Ounces . 128 oz. Per gallon

= Gallons

64 ounces = 0.5

Gallons

• Label requirements• Determine Your Field Speed• Collect from each nozzle

– Want output of one nozzle– Simply plug in the numbers

Figuring Out GPAFiguring Out GPA

GPA is given or required!GPA is given or required!Need GPM for each nozzle!Need GPM for each nozzle!

Rearrange formula

How Much To Add To The How Much To Add To The TankTank

• Acres that can be sprayed with a Acres that can be sprayed with a given volume in the tankgiven volume in the tank

• GPAGPA• Labeled RateLabeled Rate

How Much To Add To The How Much To Add To The TankTank

• Acres that can be sprayed with a Acres that can be sprayed with a given volume in the tankgiven volume in the tank

VolumeGPA

= Acres

500 gal.25 GPA

= 20 Acres

20 Acres x 25 GPA = 500 gallons

How Much To Add To The How Much To Add To The TankTank

• Acres that can be sprayed with a given volume in the tank

• GPA• Labeled RateLabeled Rate

20 acres x 3 pints/acre

= 60 pints

Gallons?

60 pints

8 pints/gal.

= 7.5 gal.

Acres x labeled rate per acre

1 gallon of Tordon per 100 gallons of water- Sprayer applied 50 GPA- Could spray 2 acres with 100 gallons

100 gallons 50 GPA = 2 acres- Rate was 1 quart per acre- Only needed to add 2 quarts per 100

gallons2 acres x 1 quart per acre = 2

quarts per 100 gallons

- Over applied by 2x ($40 per acre)