Calibrating Hand Sprayers/Spreaders for Pesticide Applications

Transcription

1 Calibrating Hand Sprayers/Spreaders for Pesticide Applications

2 Why calibrate your sprayer/spreader & yourself? Because it will ensure a precise application of the appropriate rate of chemical per a given area, thus providing: Proper pesticide performance & effective pest control Use the correct amount of product & volume/acre to effectively control pests Prevent potential pest resistance/resurgences from below label rate applications A legal, label prescribed application Stay below the legal rate maximum (total a.i. per application and total a.i. per season), or break the law An economical application that prevents unnecessary waste of time/equipment wear/fuel/labor/product = $$$

3 Because it will ensure a precise application of the appropriate rate of chemical per a given area, thus providing: Improved safety to crop and other desirable vegetation Protection of the environment & human health Prevent illegal / above-threshold pesticide crop residues Prevent worker/public/beneficial insect/wildlife exposure to higher-than-label rate residues Prevent buildup of excessive soil residues/groundwater contamination Also, because it doesn t take that much math and is easy to perform

4 Spot Sprayer Calibration How much do I put in my tank? Calibration is necessary to perform before using sprayable pre-emergent herbicides (and the majority of post-emergent herbicides as well)*. An exception = Glyphosate spot application in % v/v rates Requires attention to detail, consistency and a small amount of math

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6 Calibration Steps Start with a clean tank and nozzle (selected to provide the desired spray pattern) Sprayer choice: a backpack sprayer will allow for more consistent pumping and pressure maintenance, which will be further improved by a pressure regulating valve (either in the sprayer itself or placed in between the nozzle and wand): pressure setting/nozzle combos are designed to provide a given gal/ac output at a given walking speed* Fill tank with enough clean water to allow inspection of the nozzle & pattern, to ensure uniform coverage during the calibration exercise. Change nozzle if worn, pattern is not what is desired, or driftable fines are observed w/ the current pressure setting (or adjust pressure to match the selected nozzle tip size) If an adjustable nozzle is used (like the one I used in the upcoming picture), select the desired pattern & mark its position

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8 Measure an area 18.5 ft X 18.5 ft (= 1/128 th of acre; 128 oz/gallon). I like to use two tape measures laid out and locked in position I prefer to select a site that allows for good coverage visibility when spraying (like a driveway or parking lot). If you are in the field and coverage visibility is poor, consider using a dye Using a stopwatch, begin spraying the measured area, timing the amount of time it takes to uniformly cover it one time (it helps if someone assists with the timing).* Walking speed and nozzle height consistency are important I like to repeat the spraying step several times to attain an average time

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10 Spray into a pesticide measuring cup for the average amount of time it took spray the 18.5 X 18.5 ft square (using the same consistent pumping motion as before).* The amount measured in the cup (in ounces) is equal to the output of the sprayer in gallons/acre Does the output acquired meet the output desired (see label)*? If it doesn t, consider changing the nozzle tip size / pressure / walking speed to adjust

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12 Example Measured & marked a 18.5ft X 18.5ft square Filled Chapin Pro Series Model (internal pressure regulation set to highest setting 4 60 PSI) with clean water (Fitted with a Chapin CF Valve 30 PSI B3-8 BSP / 8006 Even fan brass nozzle). Pressure will be consistent at 30 PSI* Sprayed using a consistent nozzle height from ground & walking speed.* It took an average of 86 seconds to cover the measured area Sprayed into a 2qt measuring cup for this amount of time. Measured 40 oz, which equates to 40 gal/acre*

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16 Now how much do I add to the tank? Using the previous math example if it was determined that the sprayer output is 40 gal/acre, and I have a 4 gallon backpack sprayer, then I would divide the label designated amount of product to use per acre by 40 gallons to get the amount of product to add to a gallon. Ex. Surflan AS Specialty use rate for established landscape ornamentals = 2-4 quarts/ac* I plan to use the 4 qt/acre rate Math: 4qts/ac X 32oz/qt = 128ozs/ac / 40 gal/ac = 3.2 ounces/gallon 4 gallons X 3.2 oz = 12.8 oz/sprayer load Be consistent and safe!

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18 Useful Area calculations

19 Useful Conversions (American Standard) Liquid 1 gallon = 4 quarts 1 gallon = 8 pints 1 gallon = 128 ounces 1 gallon = 16 cups 1 cup = 8 ounces 1 ounce = ml (cc) 1 ounce = 2 tbsp. 1 tbsp. = 3 tsp. 1 tbsp. =.5 oz 1 teaspoon =.167 oz. Dry 1 pound = 16 ounces 16 oz. = 2 cups 2 cups = 32 tbsp. 1 tbsp. = 3 teaspoon = ½ ounce = 14.3 grams 1 oz. = grams

20 Useful Conversions (Continued ) Area & length 1 mile = 5,280 ft 1 acre = 43,560 ft 2 Check and use your clipboard for more conversions.

21 Spreader Calibration for Granular Herbicides How much will I need? What spreader setting do I use? Known Area / Total Product Method Know what it looks like method* Calibration trays* Most accurate: The above methods + spreader calibration

22 Know what it looks like method

23 Calibration Tray

24 DVD on Spreader Calibration

25 Works Cited TechLine For Western Rangelands: Backpack and Spot Treatment Calibration Guidelines BASF Spreader Calibration DVD Best -

26 Nate Weber Crop Production Services 855 E. Greg Street Suite 105 Sparks, NV (C) (O)