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

Calibration: 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

Measuring Ground Speed Where 1 MPH = traveling 88 feet in 60 seconds

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.

Determining Amount of Pesticide for Dilute Applications

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 1 st and 2 nd column D10 disc with a DC25 core/whirl plate –Select 60 psi –Follow same routine D8 disc with a DC45 core/whirl plate

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