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Insect Control Field Days Sponsored by the Kansas Fruit Growers Association
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
Speed(MPH)Distance(ft) x 60
Time(seconds) x 88
Where 1 MPH =
traveling 88 feet in 60 seconds
Ground Speed Measurement
Speed(MPH)Distance(ft) x 60
Time(seconds) x 88
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:
Height x 3.14 x Diameter/2 cfm
Volume Tree 2
ft. 15 x 3.14 x ft./2 15 cfm
Volume Tree 2
2650 cfm per tree
Required Air Capacity:
spacing tree
per tree cfm x sides of # x (MPH) travelof rate
cfm
CapacityAir Required
ft. 20
per tree cfm 2650 x 2 x (MPH) 1
cfm
CapacityAir Required
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)
ft 18
ft./acre sq. 43,560 x ft. 8 ft. 10
ft./acre cu. volumerow-Tree x
rowsbetween distance
ft./acre sq. 43,560 x height(ft) Tree t)diameter(fcanopy Tree
ft./acre cu. volumerow-Tree x
ft. cu. 193,600 ft. 2,420 ft. sq. 80 ft./acre cu.
volumerow-Tree x
Determining Amount of Water-Dilute
Minimum/Maximum dilute volume (GPA) =
(tree-row volume (cu. ft./acre) x min/max gal/cu. Ft.
ft. cu. 1,000
gal. 0.7 x
/acreft. cu.
volumerow-tree
gpa volumedilute minimum
ft. cu. 1,000
gal. 0.7 x
/acreft. cu.
193,000
gpa volumedilute minimum
acreper gallons 136 gpa
volumedilute minimum
Determining Amount of Water-Dilute
Minimum/Maximum dilute volume (GPA) =
(tree-row volume (cu. ft./acre) x min/max gal/cu. Ft.
ft. cu. 1,000
gal. 1.0 x
/acreft. cu.
volumerow-tree
gpa volumedilute maximum
ft. cu. 1,000
gal. 1.0 x
/acreft. cu.
193,000
gpa volumedilute maximum
acreper gallons 194 gpa
volumedilute maximum
Determining Amount of Pesticide for Dilute Applications
volumedilute x rate dilute reproduct/ac ofAmount
acre
waterof gallons x
gallons 100
pesticide of amt. reproduct/ac ofAmount
lbs./acre 3.0 acre
waterof gal. 400 x
gallons 100
pounds 0.75 reProduct/ac
lbs./acre 0.9 acre
waterof gal. 120 x
gallons 100
pounds 0.75 reProduct/ac
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
volumeeconcentrat
volumedilute ion Concentrat
3 gallons 80
gallons 240 ion Concentrat
Determining the Amount of Pesticide for Concentrate Applications
acre
waterof volumedilute standard x
waterof gal. 100
pesticide ofamount acrepesticide/ of rate Full
acre
lbs. 6.0
acre
waterof gal. 400 x
gallons 100
pounds 1.5
acre
rate full
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
rowsbetween distance
ft./acre sq. 43,560 elength/acr row
ft. 2,420 ft 18
ft./acre sq. 43,560
Selecting Nozzle Size:
Based on gallons/acre = sprayer discharge rate
495
ft. width row x MPHGPA x GPM
14.84 495
ft. 18 x 3 x 136 GPM
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
