Tree Fruit and Nut Sprayer Calibration 101
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Tree Fruit and Nut Sprayer Calibration 101 Franz Niederholzer, Farm Advisor, Univ. of Calif Gwen Hoheisel, Extension Educator, Washington State Univ. Andrew Landers, Extension Specialist, Cornell University Rich Derksen, USDA A tree fruit or nut grower typically sprays pesticides worth $100-650/acre/year. That’s $10,000 to $65,000/year for a 100 acre orchard. If the sprayer output is 10% more than recommended in that orchard, $1000- $6500 can be lost in a year. To get the right amount of spray materials in the right place, carefully calibrate your sprayer(s) at least once a year. For the most efficient spraying, calibrate your sprayer to match key canopy growth stages – dormant, full bloom, spring, preharvest, etc. Calibrate your sprayer only once a year? Do it just before your preharvest spray, when the canopies are the densest and uniform spray coverage and effective pest control is most challenging. The following is a review of the basic steps to calibrating an air-blast sprayer using hydraulic nozzles, such as Rears, Durand-Wayland Nelson-Hardie, AirOFan, etc. Accurate pesticide delivery per acre requires accurate delivery of spray volume/acre. However, sprayers must be calibrated to deliver the correct gallons/acre AND that volume must be uniformly delivered throughout trees for effective pest control. Proper sprayer air volume delivery is a key to spray coverage quality . With the tank half filled with clean water plus kaolin clay product (Surround ® , etc.), run the sprayer down a typical row in orchard at the tractor gearing and RPMs you commonly use for preharvest spray. Shut off or deflect any air not directed into the tree. Check coverage in the hardest part of the tree for spray to reach – the top center. No coverage or patchy coverage in the tree tops? Increase fan air volume delivery into each tree by slowing down ground speed – works on all sprayers -- or changing fan gearing or blade angle – works on sprayers with those options. Uniform but thin coverage in tree tops? Increase spray volume and check again. Once you find the settings that give good spray coverage, measure ground speed. Count trees/minute or drive the sprayer over a set distance. Using the ground speed in feet/minute and the distance across a tree row, calculate acre/minute (APM) sprayed.
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Basic sprayer calibration for fruit and nut growers.
Transcript of Tree Fruit and Nut Sprayer Calibration 101
Tree Fruit and Nut Sprayer Calibration 101Franz Niederholzer, Farm Advisor, Univ. of Calif
Gwen Hoheisel, Extension Educator, Washington State Univ.Andrew Landers, Extension Specialist, Cornell University
Rich Derksen, USDA
A tree fruit or nut grower typically sprays pesticides worth $100-650/acre/year. That’s $10,000 to $65,000/year for a 100 acre orchard. If the sprayer output is 10% more than recommended in that orchard, $1000-$6500 can be lost in a year.
To get the right amount of spray materials in the right place, carefully calibrate your sprayer(s) at least once a year. For the most efficient spraying, calibrate your sprayer to match key canopy growth stages – dormant, full bloom, spring, preharvest, etc. Calibrate your sprayer only once a year? Do it just before your preharvest spray, when the canopies are the densest and uniform spray coverage and effective pest control is most challenging. The following is a review of the basic steps to calibrating an air-blast sprayer using hydraulic nozzles, such as Rears, Durand-Wayland Nelson-Hardie, AirOFan, etc.
Accurate pesticide delivery per acre requires accurate delivery of spray volume/acre. However, sprayers must be calibrated to deliver the correct gallons/acre AND that volume must be uniformly delivered throughout trees for effective pest control.
Proper sprayer air volume delivery is a key to spray coverage quality. With the tank half filled with clean water plus kaolin clay product (Surround®, etc.), run the sprayer down a typical row in orchard at the tractor gearing and RPMs you commonly use for preharvest spray. Shut off or deflect any air not directed into the tree. Check coverage in the hardest part of the tree for spray to reach – the top center.
No coverage or patchy coverage in the tree tops? Increase fan air volume delivery into each tree by slowing down ground speed – works on all sprayers -- or changing fan gearing or blade angle – works on sprayers with those options. Uniform but thin coverage in tree tops? Increase spray volume and check again. Once you find the settings that give good spray coverage, measure ground speed. Count trees/minute or drive the sprayer over a set distance. Using the ground speed in feet/minute and the distance across a tree row, calculate acre/minute (APM) sprayed.
Nozzles determine spray volume delivery. Select the spray volume -- gallons/acre (GPA) -- you want to spray. Calculate the gallons/minute (GPM) the sprayer needs to deliver. GPM = APM * GPA. Use the nozzle manufacturer’s catalog to select the size and number of nozzles to deliver the needed GPM at the sprayer pressure you use.
In the field, set nozzles on the sprayer to match canopy thickness. Place larger nozzles adjacent to thicker canopy. Close nozzle ports that spray outside the canopy.
Ground check. Completely fill the sprayer with clean water. Park the sprayer and tractor in a flat, open location. Run the sprayer for 1-3 minutes at the pressure and RPM setting you will use in the orchard. Shut off the sprayer and measure back the amount of water it takes to completely refill the sprayer. A marked bucket works fine. GPM = gallons required to refill/time run (minutes). Checking volume output/time for each nozzle (nozzle GPM) and summing all to determine sprayer GPM is preferred (see photo). This approach identifies worn or damaged nozzles. Calculate GPA sprayed as if you were running at the ground speed you determined earlier. GPA = GPM/APM. Is the sprayer delivering the GPA you want? If not, adjust nozzles (preferred) or pressure (if a small change is needed) to get the volume output you need. Repeat until you get the GPA you
want. Note: Changes in pressure will change spray droplet size and possibly coverage, so recheck spray coverage if you change pressure to adjust spray volume (GPA) delivery. On-line guides to sprayer calibration are at:
1. http://www.ncw.wsu.edu/treefruit/calibration.html2. http://www.nysaes.cornell.edu/ent/faculty/landers/pestapp/index.htm#grape 3. http://www.youtube.com/watch?v=_mAB41soyxE
Equipment for measuring nozzle flow from individual nozzles.
