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ATV-RAATS
Reduced Agent and Area
Treatments


How to set up your ATV for RAAT of grasshoppers

For advice on choosing an ATV for spraying pesticides, click here.(Adobe Acrobat Required; need it?)

1. ATV Specifications:

ATVs vary widely in their capacity to carry loads and handle accessories.  To carry a 25 gallon spray tank requires at least 220 pounds of capacity on the rear cargo rack, and running a large pump, requires a heavy duty electrical system.  Consult your ATV�s operator�s manual or dealer for the specifications of your machine before you buy spray equipment.

2. Tank Size:

Tanks are commonly available in 12 to 25 gallon capacities and water weighs 8.34 pounds/gallon.  Do not exceed the weight carrying capacity of your ATV, but for efficiency choose the largest tank your ATV can safely carry.

3. Pump Size & ATV electrical capacity:

Pumps are commonly available in 1.4 to 5 gallons/minute (GPM) sizes.  Increased flow rates require more electrical power from the ATV�s alternator.  In order to work properly all nozzles need a specific minimum flow rate supplying them.  Determine your ATV�s electrical capacity, chose a pump it can run, and then a nozzle or nozzles the pump can supply.

4. System Design:
 
Nozzle Mounting Aprrox. Cost Swath Width Flow Rate Pros Cons
Conventional boom mounted $120 complete system 12-14 ft depends on nozzles A,B,F W,Z
Micron Micromax CDA boom mounted $225 per nozzle 5 ft/nozzle 1/8 GPM C,F,G W,X,Y,Z
Directional Boom-less:
Boom Buster #140 or #125
Hypro Boom Xtender XT010
Boominator 1250
central mount $90-$100 per nozzle 15-18 ft 1.7-2.4 GPM B,D,E U,V,Y
Full pattern Boom-less:
Spraying Systems 1.4 KLC Fieldjet
Boominator 1250FS
central mount $40-$90 per nozzle 17-21 ft 0.7-1.0 GPM A,B,C,D,G T

Pros:
A = relatively low cost
B = simple, uncomplicated design
C = low volume allows more acres to be treated per tank load
D = rugged boom-less design is difficult to damage
E = directional capability allows treatment in windier conditions
F = very uniform, ideally-sized droplets
G = suitable for smaller capacity pumps, allowing lower flow rates
Cons:
T = requires a mounting bracket that projects at least 22 inches from the back of the ATV
U = requires a high capacity pump (> 1.7 GPM)
V = nozzles require a relatively high volume per acre, unless ATV application speed is kept greater than 12 mph
W = must be mounted on a boom, and requires at least two nozzles per boom
X = relatively narrow swath width
Y = expensive, compared to competitors
Z = booms are subject to breakage, especially in rough country

For more information on setting up an ATV for spraying pesticides, click here. (Adobe Acrobat Required; need it?)

Calibration

After you have assembled your spray system you need to calibrate it to determine the total volume of fluid that will be applied per minute.  One way to do this is to:

1)  Fill your system with the carrier fluid (no insecticide), and with ATV engine running and parked, turn on the spray and adjust the regulator to achieve the desired swath width (varies with nozzle type) and measure this width in feet (most easily done on concrete or bare ground).

2)  Refill the tank to a reference mark with carrier fluid and in the area you are going to treat, or area with similar terrain, drive the ATV to determine a safe speed (in mph) for application.

3)  Drive at the application speed and spray for exactly 1 minute then stop and carefully determine the amount of carrier fluid it takes to refill the tank back to the reference mark.  Repeat this step two or three times to determine an average of the volume applied in 1 minute.  The value will be your estimate of gallons/minute (GPM).

4)  Calculate how many acres you can spray in 1 minute by using the formula:

  Speed (in mph) x Swath width (in feet) ÷ 495 (a constant) = # Acres Per Minute (APM)

5)  Divide the GPM (determined in step 3) by the APM figure from step 4 to determine gallons/acre (GPA) that you will be applying.

Example:

 Using Boom Buster #140 nozzles, you find that a single nozzle produces a 17-foot swath, and spraying at 15 mph, on smooth prairie, puts out 2.25 GPM.  Using the formula we can calculate the gallons/acre treated.

  GPM = 2.25
  APM = 15 mph x 17 feet ÷  495 = 0.515
  GPA = GPM ÷ APM = 2.25 ÷ 0.515 = 4.37

So, there will be 4.37 gallons of fluid (carrier plus insecticide) applied per treated acre.  This volume is equal to 4 gallons and 47 ounces (0.37 x 128 ounces/gallon = 47 ounces) or 4 gallons and 3 pints of fluid.

Using these figures, the maximum area that could be treated with a 25 gallon tank is 5.7 acres (= 25 gallons ÷ 4.37 gallons/acre).  Let�s assume that you�ve decided to use 1 ounce of Dimilin 2L per treated acre, with no adjuvants.  The actual process of treatment should follow these steps:

1)  Fill the tank about half way with carrier fluid.
2)  Add 5.7 ounces of Dimilin 2L, under agitation (using the spray pump re-circulation mode if available).
3)  Fill the tank to the 25-gallon mark.
4)  Spray 5 acres (approximately 10 minutes of spraying, at the calculated rate of 0.515 APM).
5)  Stop and check the volume left in the tank.  It is better to not run your spray system completely dry while spraying.  If your calibration is correct and you have been holding your speed close to 15 mph you should have approximately 3 gallons of spray mixture left (0.7 acres worth).
6)  Add water to half-fill the tank.
7)  Add 5 fluid ounces of Dimilin under agitation.
8)  Fill the tank back to 25 gallon mark.
9)  Spray another 5 acres (10 minutes).
10)  Repeat the refill-and-application process (steps 5-9) until you are done.

If you decide to use other insecticides or adjuvants you will need to adjust for their contribution to the total volume.  For example if you decide to apply 32 ounces of carbaryl per acre using our example system, then you only need 4 gallons and 15 ounces of water per acre.  Recall that we would apply 4 gallons and 47 ounces/acre, of which 32 ounces will be carbaryl, leaving 4 gallons and 15 ounces of water.  Be sure to double check all your calibrations, as over- or under-application of insecticide is a costly � and perhaps dangerous � mistake.

ATV Bait Application and spreader

Peacock Industries Inc. makes an electrically powered bran bait spreader that attaches to the rear rack of an ATV.   The spreader can carry 50 pounds of bran in its hopper, produces a 16-foot swath, and has an adjustable flow rate.   The amount of bran applied per acre depends on the speed of the ATV and the flow rate.  Recommended rates vary from 1 to 10 pounds/acre, depending on the grasshopper developmental stage and the severity of the infestation.  However, not all pest grasshopper species will take bait.  Determine the susceptibility of the species present in your area before using this method.  This information can be obtained at http://www.sidney.ars.usda.gov/grasshopper/Handbook/II/ii_12.htm; Recommendations for less than 100% coverage have not been established for bran bait.

Speed vs. terrain

The maximum speed at which an area can be treated will vary with terrain, ATV specifications, operator skill, vegetation, and the possibility of encountering hidden obstacles (e.g., rocks, holes, or animal trails).  On smooth land, application speeds up to 15 mph are safe and comfortable for the operator.  Common sense and the hazards of the terrain should determine a safe, appropriate application speed.  In a typical application at 15 mph with a 17 foot swath and a 25% coverage, 2 acres would be protected every minute.


For more information contact:
Professor Jeffrey A. Lockwood
Association for Applied Acridology International and
Department of Renewable Resources
University of Wyoming College of Agriculture
P. O. Box 3354
Laramie, WY 82071-3354
(307) 766-4260; lockwood@uwyo.edu


Funding for RAAT research has been provided by the state of Wyoming (Legislature, Department of Agriculture, Weed and Pest Districts, University of Wyoming), U.S. Department of Agriculture (Western Regional IPM Project, APHIS, and CSREES), and cooperating industries.