Calibrating Homeowner Equipment

EquipmentEquipment

• Hose-end sprayers• Compressed air sprayers• Knapsack sprayers• Trombone sprayer/ bucket (stirrup)

sprayer• Fogger• Spray bottle

Types of ApplicationTypes of Application

• Foliage sprays (shrubs, trees)• Area coverage (soils or lawns)• Spot sprays• LAWN

Fertilization Weed control Insect/Fungi control

• HORT Fertilization Insect/Disease control Dormant oil treatments

Area Coverage (soils or lawns)Area Coverage (soils or lawns)

• Application should provide even wetting of entire surface with no areas of intense concentration

• Often recommend to cut application rate in half and cover area twice. at opposite angles - not always good since

application rate and speed not proportional in same direction alternating rows per

application

Foliage Sprays (shrubs, trees)Foliage Sprays (shrubs, trees)

• Most recommendations advise spraying the foliage with diluted chemical to the point of runoff

• Difficult to do uniformly

Calibration ProcedureCalibration Procedure

• Add a known amount of water to the sprayer.

• Spray the water as uniformly as possible to the point of runoff.

• Measure the amount of water left in the sprayer and subtract it from the amount added to the sprayer in the beginning

Calibration ProcedureCalibration Procedure

• Measure and mark off an area of 1000 sq ft.

• Add a measured amount of water to spray tank, spray area, and then measure the amount of water remaining in the tank.

• The difference between the amount in the tank before and after spraying is the amount used.

Alternative Calibration Procedure

Steps: Mark off a calibration course of 1000 sq. ft. Accurately measure the time required to spray

the calibration course using a proper technique. Remember only record the amount of time the gun is actually spraying.

Measure the flow rate from the gun. Using the time recorded in step 2, spray into a calibrated container for that same length of time.

Amount in the container represents the application rate per 1000 sq. ft.

Example:It took 50 seconds for an applicator to spray

the 1000 sq. ft. calibration course. The amount of spray collected from the gun in the 50 seconds was 1.4 gallons.

The application rate for this example is:

1.4 gallons per 1000 sq. ft.or

61 gallons per acre (43.56 x 1.4)

Alternative Calibration Procedure

Spot SprayersSpot Sprayers

• Fence rows.• Weeds in beds or turf.• Calibrate sprayer same as in Area

Coverage, but estimate area of spots to be covered when figuring amount of water and chemical to add to spray tank.

Hose-end SprayersHose-end Sprayers

• Simple and inexpensive• Use water pressure from garden

hose to distribute the spray.• Chemical added to jar as

concentrate.

Siphon ActionSiphon Action

• Draws the solution in the jar and mixes it at a predetermined rate with the water spraying out of the nozzle.

siphoning tubesiphoning tube

Marks on Jar:Marks on Jar:

• Gallon scale on jar indicates total amount of water and pesticide solution in the jar applied.

• Ounces give amount actually in jar while gallons give amount supposed to be sprayed out once mixed with water from hose.

• ie: Jar filled to 10 gal mark (25 oz of solution). When

jar is empty, 25 oz has been applied with 10 gallons of water.

Calibration:Calibration:

• Measure and mark off an area of 1000 sq ft.• Fill jar with water to a measured level.• Spray marked area uniformly and then check

the amount left in the jar.• Add to the jar the chemical needed to spray

the number of sq ft in your yard or garden area. Then add enough water to the jar to bring the level up to the gallonage mark required to cover the sq ft to be treated.

Notes:Notes:

• To obtain uniform application cut rate in half and spray area twice; overlapping motion as you walk.

• Always use uniform walking speed during application.

Sprayer AccuracySprayer Accuracy

• Water pressure affects accuracy of sprayer.

• Designed to operate at 40 psi (typical water pressure found in most areas).

• Hose length not to exceed 50 ft and min. dia. of 5/8 inch.

Example Calibration Problem

• Your yard is 3500 ft2, and you want to apply a pesticide at the rate of 3 oz/1000 ft2 (according to label).

• In calibration you added water to the 6 gallon mark on the jar. After spraying an area of 1000 ft2, equivalent of 4 gal. is left in the jar.

• How much water and chemical should you put in the jar?

Example of CalibrationExample of Calibration

• Area covered = 1000 ft2

• 6 gal. - 4 gal. = 2 gal.• Yard is 3500 ft2

• From label: 3 oz/1000 ft2

• (3500 x 3)/1000 = 10.5 oz

• The jar is filled to:• ( 3500/1000) x 2 = 7

gal.

50 ft50 ft

20 ft20 ft 3500 ft3500 ft22

Compressed Air SprayersCompressed Air Sprayers

• Pesticides already mixed to their proper spraying dilution

• Tank pressurized with compressed air or carbon dioxide

Pressure Control:Pressure Control:

• Fill tank 2/3 full with spray material so considerable air space if left for initial expansion.

• Repressurize tank frequently.• If pressure gage is used, repressurize

when pressure drops about 10 psi from initial reading.

Notes:Notes:

• Shake occasionally to keep materials in solution/suspension/emulsion.

• Each sprayer comes with a nozzle that can be adjusted to provide fine spray, coarse spray, and solid stream.

Trombone Sprayer/ Bucket (stirrup) SprayerTrombone Sprayer/ Bucket (stirrup) Sprayer

• Inexpensive, durable, telescoping, plunger-action pumps that provide continuous spray.

• Can reach tops of 25 to 30 foot trees.

• Must carry bucket with you.• Bucket sprayer involves a foot

support for the bucket

FoggerFogger

• Used in small areas to control insects• Oil based insecticide is used along

with a lit propane tank to volatilize the spray and produce smoke or fog.

• Allow fog to dissipate before reentry to area.

• Very likely to drift so extreme care must be taken.

Spray BottleSpray Bottle

• House plants, small flower beds and gardens, small shrubs

• Spray to point of runoff• Simply add proper amount of water

and pesticide according to label

Calculations

GPA=

5940

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

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!