Application Technology Problems
Liquid Application Problems
1. A farmer wants to apply a burndown herbicide to his no-till field at a rate of 12 gallons of spray mix per acre. His tractor
speedometer has been calibrated and indicates he will be traveling an average speed of 9 miles per hour. But with previous data, a speed
range from 5 to 12 mph might be expected. The sprayer boom width is 60 feet and has a nozzle spacing of 20 inches. What should be the
flowrate from each nozzle and what size nozzle should be used at what pressure range? Utilize a AIXR TeeJet Air Induction XR nozzle for
The nozzle flow rate can be calculated from the following equation:
GPM = GPA x S x W
GPM = nozzle flow rate (gallons per minute)
GPA = sprayer application rate (gallons per acre)
S = speed (miles per hour)
W = width sprayed by each nozzle (inches)
5,940 = a constant for conversion of units
Reference, TeeJet® Technologies Product Catalog, Catalog 51A at http://www.teejet.com/literature_pdfs/catalogs/C51A/cat51a_us.pdf for
2. A farmer wants to sidedress nitrogen to a corn crop at varying rates from 50 to 100 pounds of nitrogen per acre. He will be using a
28% UAN as the source of nitrogen (Note: a conversion from lbs/acre to gal/acre will need to be made). His tractor speedometer has been
calibrated and indicates he will be traveling 8 miles per hour. The sprayer boom width is 60 feet and has a nozzle spacing of 30 inches.
What should be the range of flow rates from each nozzle and what size nozzle should be used at what range of pressures? Utilize a Stream
Jet VR nozzle – http://www.teejet.com/literature_pdfs/bulletins/B101_SJ-VR.pdf
or Vari-Target nozzle – http://www.spraytarget.com/varitarget.htm for this problem.
Dry Fertilizer Application Problems
3. A farmer wants to apply phosphorus at rates varying from 30 to 150 pounds per acre. (Note: you will need to convert lbs of phosphorus
per acre to lbs of DAP per acre. DAP is 18% phosphorus or analysis of 18-46-0) He will be using a DAP as the source of phosphorus with a
density of 60 pounds per cubic feet. His tractor speedometer has been calibrated and indicates he will be traveling 12 miles per hour.
The fertilizer cart has a spread width is 60 feet. What gate height and range of drive RPMs will provide the combination is required for
4. A farmer wants to apply potash at rates varying from 50 to 200 pounds per acre. (Note: in this problem potash is the product so no
conversion is needed.) The potash he will be using has a density of 72 pounds per cubic feet. The fertilizer cart has a spread width is
60 feet. He wants to have a gate height setting of 2 inches. What would be an adequate drive RPM range and a travel speed combination
would be required for this application?