Application Equipment and Calibration Flashcards

An applicator is calibrating a boom sprayer. After collecting the output from several nozzles for one minute, they find that one nozzle's output is 15% higher than the average of the other nozzles. What is the most appropriate action to take?

Answer: Replace the nozzle because its output is significantly outside the acceptable range.

Nozzles should have a uniform output to ensure even application of the pesticide. A variation of 10% or more from the average indicates a worn or faulty nozzle that needs to be replaced. Adjusting pressure or speed would affect the entire boom, not correct the issue with a single nozzle.

Which of the following changes to sprayer setup would be most effective in reducing pesticide drift?

Answer: Switching to low-drift nozzles, such as air-induction types.

Low-drift nozzles, like air-induction or venturi nozzles, are specifically designed to produce larger, heavier droplets that are less likely to be carried away by wind. Increasing boom height, using nozzles that create fine droplets, and increasing pressure all tend to increase the potential for spray drift.

An applicator needs to spray a rectangular field that is 1,200 feet long and 500 feet wide. The calibrated sprayer applies 20 gallons per acre (GPA). How many total gallons of spray mixture are needed to treat the entire field? (43,560 sq. ft. = 1 acre)

Answer: 275 gallons

First, calculate the total area of the field in square feet: 1,200 ft * 500 ft = 600,000 sq. ft. Next, convert the square footage to acres: 600,000 sq. ft. / 43,560 sq. ft./acre = 13.77 acres. Finally, calculate the total gallons needed: 13.77 acres * 20 GPA = 275.4 gallons. The closest answer is 275 gallons.

During a pre-application equipment check, you discover a small leak in a hose connection. What is the correct immediate action?

Answer: Stop and repair the leak by tightening the connection or replacing the faulty part before any application begins.

Any leak in the pesticide application equipment must be repaired before use. Leaks can cause pesticide to drip onto non-target areas, expose the applicator to the chemical, and result in an incorrect application rate. Temporary fixes or continuing with a known leak are unsafe and unprofessional.

To double the flow rate of a sprayer by only adjusting the pressure, the pressure must be:

Answer: Quadrupled (increased by 4 times).

The relationship between pressure and flow rate is not linear. To double the flow rate from a nozzle, the pressure must be increased by a factor of four. This is because flow rate is proportional to the square root of the pressure. Therefore, to double the flow, you must square that factor (2x2=4).

Which type of nozzle is generally best suited for broadcast application of herbicides, producing a tapered-edge flat spray pattern that requires overlapping?

Answer: Flat-fan nozzle

Flat-fan nozzles are the most common type used for broadcast spraying of herbicides. They create a tapered-edge pattern that, when spaced correctly on a boom, provides uniform coverage through overlapping sprays. Hollow-cone and full-cone nozzles are typically used for insecticides and fungicides where foliage penetration is critical, while flooding nozzles produce a wide pattern but are less uniform.