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Insect Control Field Days. Sponsored by the Kansas Fruit Growers Association. Applications for Fruit Trees. Robert E. Wolf Extension Specialist Application Technology. Biological and Agricultural Engineering. Placing the correct amount of product in the desired location.
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Insect Control Field Days Sponsored by the Kansas Fruit Growers Association
Applications for Fruit Trees Robert E. Wolf Extension Specialist Application Technology Biological and Agricultural Engineering
Placing the correct amount of product in the desired location. High volume by hand or with air Low volume with air Amount of delivered air is important. Displace 2X the tree volume – cfm Location of delivered air is important Coverage uniformly throughout the tree Minimize spray drift away from the orchard Knowing the travel speed is essential Calibration:
Where 1 MPH = traveling 88 feet in 60 seconds Measuring Ground Speed
Ground Speed Measurement Example: You drive along a 150-foot measured course and discover that 30 seconds are required to complete the course. Determine the MPH. Speed = 150 x 60 = 9,000 = 3.4 MPH 30 x 88 2,640
Air Delivery Calculation: 2650 cfm per tree
Required Air Capacity: 23,320 cfm 1 mph = 88 ft. per sec.
Application Rates: • Product per 100 gallons of water • Based on standard trees • Point of run-off (dilute) • @ 400 gal/acre • Product per acre • Based on modern air carrier sprayers • Speed sprayers • More efficient • Point of run-off not necessary • Low volume (40 – 80 gal/acre) • Also referred to as concentrate spraying
Dilute Spraying: • Dilute volume = the amount of spray liquid to cover one acre of trees to point of run-off. • Determined by experience or using a formula • Tree-row volume method for smaller trees • Determine dilute volume • Determine the concentrate rate of pesticide/acre
Tree-Row Volume: (Dilute) • Based on tree size and spacing • Table (Ohio State Extension Bulletin 892) • Rule of thumb based on tree density • 0.7 to 1.0 gal/1000 cu. ft. • Row length per acre = 43,560 sq. ft. in an acre divided by the distance between rows in feet.
Determining Tree-row Volume Tree-row volume = (canopy width) x (tree height) x (row length per acre)
Determining Amount of Water-Dilute Minimum/Maximum dilute volume (GPA) = (tree-row volume (cu. ft./acre) x min/max gal/cu. Ft.
Determining Amount of Water-Dilute Minimum/Maximum dilute volume (GPA) = (tree-row volume (cu. ft./acre) x min/max gal/cu. Ft.
Concentrate Spraying: • As water amount decreases the pesticide amount increases proportionately – BUT NOT BY ADDING MORE PESTICIDE TO THE TANK!!! • Example: • 1/3 less water means 3X pesticide
Determining the Amount of Pesticide for Concentrate Applications
Calculations for Concentrate Applications: • Using the per acre rate level • No calculations needed • Take rate directly from the label • Example (Assail 70WP) • Pome Fruits: 1.0 – 3.4 ounces per acre • Apply in at least 80 gallons per acre • Acres based on the tree spacing
Selecting Nozzle Size: Based on gallons/acre = sprayer discharge rate 14.84/2 = 7.42 gpm / side / 7 nozzles = 1.06
Selecting Correct Orifice: • Chart – TeeJet (hollow cone tips) • Select a pressure along top (80 psi) • Move down column to locate 1.07 gpm • Move left to 1st and 2nd column • D10 disc with a DC25 core/whirl plate • Select 60 psi • Follow same routine • D8 disc with a DC45 core/whirl plate
For more information contact: rewolf@ksu.edu www.bae.ksu.edu/rewolf/