Cecil Tharp MSU Pesticide Education Program Pesticide Education Specialist Department of Animal and Range Montana State University

 Calibration is to ensure that your equipment is applying the correct amount of pesticide material uniformly over a given area.  To do this we must know:  Solution delivered over a given area.  Often expressed as GPA or gal per 1,000 square ft. Q1: Can you just add product to tank and understand what it’s delivering to pests?

1. Twice 2. Once 3. Once every few years 4. Never

 Use the MontGuide titled “Calibrating Ground Sprayers Using Shortcut Methods  128 th Acre Method  Backpack Sprayers  Boom Sprayers  Shortcuts for Broadjet Sprayers  Use the Calibration PocketGuides

 Stopwatch  Measuring Tape  Measuring Container  Pencil and paper  Source of fresh water

 Use water when calibrating  Use same nozzles and filters as when spraying  Measure an 18 ½ by 18 ½ ft area.  Spray area with water and time how long it takes  Constant speed and constant pressure  Spray into container for same amount of time.  Ounces = Gallons Per Acre Applied

Spray Management Valve Reduces number of times manual sprayer needs to be pumped. Regulates pressure for steady, even flow. Shuts off spray if pressure falls below set amount. Allows for constant, precisely calibrated spray application. Available in 15, 21, 29, and 44 psi $15 – 20 per valve

Find GPA? How?

Table 1. Suggested minimum spray heights Spray Height (inches) 20" spacing30" spacing Spray Angle Degrees 30% overlap100% overlap30% overlap100% overlap NR NR29-31NR NR NR-Not recommended if height is above 30 inches.

 Check nozzle output for 1 minute and get average  If each nozzles output is not greater or less than 10% off of average, all is well.  How?

 To find 10%  Find your average…48 oz  Move the decimal place one space to the left. 48. = 4.8 This is a 10% error  Now add 4.8 to 48 for +10%  Subtract 4.8 from 48 for -10%  10% Error range = 43.2 and 52.8  Any nozzle output between 43.2 and 52.8 is OK!

Spot On Spray Calibrator Determines Nozzle Flow Rate $ Agrimart Owensboro, Kentucky Tel:

 Use spot on calibrator in conjunction with the online Teejet Spray Calibration Calculator to determine GPA of sprayers quickly.  calculator.aspx  Can be used for spray days, or calibration sessions when quick estimates are needed.  Nozzle Flow Rate  Sprayer Speed  Application Rate (output)  Nozzle Spacing

1 st – Determine Nozzle output is same. 2 nd – Flag out Course Length based on your nozzle spacing 18” = 227’ course length 20” = 204’ course length 30” = 136’ course length 40” = 102’ course length  Or 340 / spacing in feet 3 rd - Drive course in gear and rpm you will use when spraying and time yourself. Repeat 2 – 3 times.

4 th - Collect liquid from 1 nozzle for this amount of time 5 th - Ounces of liquid collected = GPA

 18” wide nozzles, 6 nozzles  What to do?  Travel 227’ and time  30 seconds, then what?  Measure amount delivered in that 30 seconds  15 ounces in 30 seconds  15 GPA

Calibrating Broadjet (boomless) Sprayers

Determine Test Strip Distance: Divide your spray swath (ft) into then multiply times 10. This is your test strip distance (ex: / 30 feet = x 10 = feet. Run test strip and time (it took 25 seconds to drive ft). Collect your broadjet output (ounces) f or the time it took to drive test strip (Collected 130 ounces in 25 seconds). Divide the amount collected in ounces by 10. This equals GPA.  130 / 10 = 13 GPA

25’ wide swath, 1 Broadjet What to do? Travel 136’ and time 27 seconds Measure solution delivered in 27 seconds 200 ounces in 27 seconds What is the GPA? 20 GPA

 Speed  Slower speed increases output  Pressure  Only slight adjustments  Nozzle size  Use 5940 to get you close  Not meant for fine adjustments  Nozzle spacing  Often preset

 Acres * GPA = Volume in Tank  You have wish to spray 10 acres with a sprayer calibrated at 30 GPA. How much solution would you need to cover this area?  10 acres * 30 GPA = 300 Gallons

 Acres * product rate = Total Product  Product Rate = 2 pints / Acre  You will be spraying 10 acres  20 pints of product

 Use PocketGuides  Pesticide per gal = Product Recommendation / GPA  Gallons of solution in tank = 3 gallons  Product Label Recommendation = 3 oz per acre  GPA of Sprayer = 30 GPA  How much pesticide product do you need to add to tank.  3 / 30 = 0.1 oz per gallon of solution

You have a calibrated output of 20 GPA with your boom sprayer. You need to spray 300 acres. #1 - How much of a spray mixture will you need? Acres * GPA = Volume in Tank = 6000 gallons You need to apply 2 oz / acre of Warrior 1E. #2 - How much product do you put in tank? Acres * product rate = 600 oz of Warrior or Product Recommendation / GPA = 2/20 = 0.1oz per gal  0.1oz x 6,000 gallons = 600 oz of Warrior

#3 You have 20” spaced nozzles and travel 204’ in 25 seconds. What next? -You collect 10 ounces in 25 sec. -What is your GPA? GPA = 10 GPA

#4: What width and length would easily qualify for using the short cut 128 th acre method for calibrating your backpack sprayer? #5 Your hand sprayer is calibrated at 30 GPA. You are applying Tordon 22K at 16 oz / acre, and wish to mix up 4 gallons of solution. How much product do you add to tank (in ml’s)? Product Recom / GPA = 16oz/30 = 0.53x30 = 16 ml 16 ml’s per gallon x 4 gallons = 64 ml 18 1/2 x 18 ½ feet

Always Be Prepared!