CROP 440/540 Weed Management
Sprayer Calibration Final Set
1) You have a 20 foot wide sprayer with 15 nozzles. The average output per nozzle is 200 mL in 15 seconds. It takes you 30 seconds to drive 150 feet. The herbicide label says to apply 1.5 quarts of product per acre. The tank is 1,000 gallons. Conversion factors 3,785 mL in a gallon. I will not provide the conversion of square feet to an acre. You must memorize this. Please answer:
a) What is the sprayer output in gallons per acre?
b) How many acres can be sprayed with a full tank?
c) How much product needs to be added to each tank?
2) A tractor sprayer has a 30 foot boom with 30 nozzles and a 200 gallon tank. While you are driving in first gear, it takes the tractor 27 seconds to drive 150 feet. The pressure at the nozzle is 40 psi. You measure the output per nozzle as 130 mL in 15 seconds. Please answer:
a) What is the sprayer output in gallons per acre?
b) How many acres will you cover with one tank?
3) A sprayer has 20 nozzles over a boom width of 36 feet. The average output per nozzle is 365 mL per 30 seconds. It takes you 22 seconds to drive 100 feet. The label says to apply 1 quart of product per acre. The tank is 300 gallons. Please answer:
a) What is the sprayer output in gallons per acre?
b) How many acres will be covered with one tank?
c) How much product needs to be added to each tank?
4) You have a spray boom that has 18 nozzles, spaced 20 inches apart. Each nozzle sprays a 10 inch band over the row. During a calibration exercise, 2.5 gallons were sprayed while the tractor drove 300 feet. Please calculate:
a) What is the total width (in feet) covered by the spray pattern?
b) What is the GPA of this sprayer (to one decimal point)?
5) You have a 5 acre grass pasture that is heavily infested with Canada thistle. To get rid of the thistle you decide to treat it with Tordon 22K (2.0 pound active ingredient/gal) at a recommended rate of 0.75 lb ai/a. Your 200 gal sprayer delivers 35 GPA of water.
a) How much Tordon 22K should be added to the spray tank to treat the 5 acre pasture?
6) You’ve installed a brand new nozzle on your sprayer in spot 1. It discharges 28 ounces per minute at 40 psi. You collect the following measurements for nozzles 2–10 and their output is displayed in the chart below.
a) If you allow for a +/- 5% variation from the new nozzle, which of these nozzles needs to be replaced?
| Nozzle | Nozzle Flow Rate (oz/min at 40 psi) |
| 1 | 28 |
| 2 | 27.5 |
| 3 | 26 |
| 4 | 29.5 |
| 5 | 26.8 |
| 6 | 27.2 |
| 7 | 28.3 |
| 8 | 25.8 |
| 9 | 29.2 |
| 10 | 27.6 |
7) Which type of nozzle is widely used for broadcast spraying?
8) What are three common spray angles for flat fan nozzles?
9) Name three common materials used to construct nozzles.
10) What is a nozzle screen?
