Using Low Pressure Sprayers

Bulletin 705

Maintenance of Application Equipment

Sprayers should be cleaned after each day's use.

1. Open the tank drain plug and hose down the inside of the tank.
2. Close the drain plug and put 50 gallons or so of water in the tank.
3. Remove and clean all nozzles and screens.
4. Run water through the system.
5. Replace all nozzles and screens.

To clean after using a herbicide:

1. Clean the system with a detergent (1 pound to 50 gallons of water) and rinse.
2. Fill the tank with a solution of one part household ammonia to 100 parts water.
3. Circulate for five minutes.
4. Run some through the nozzles.
5. Let stand six to 12 hours.
6. Spray out and then rinse the system with water.
7. Test on sensitive plant for positive test.

Read the instruction manual provided by the equipment manufacturer. Follow manufacturer's recommendations. Parts requiring frequent checking are: pressure gauges, nozzles, strainers and leaking connections. Pumps must be checked to make certain they have enough capacity to supply the nozzles and provide for agitation.

Record Keeping

Ohio Regulations require commercial applicators to keep accurate records of all applications of pesticides. However, such records should be kept by anyone applying pesticides. Their main use, with respect to equipment, is to assure that the desired quantity of material was applied. You should record:

1. Date of application
2. Location
3. Area treated in acres or square feet
4. Pesticide used- trade name and lot number- amount in pounds or gallons
5. Equipment used
6. If spraying, the number of tankfuls used
7. Swath width
8. Wind direction and velocity
9. Date of re-entry, if applicable

From this data you can determine actual application rates. The equipment can be adjusted to correct for things such as nozzle wear and changing characteristics of the material being applied. It is only through careful checking of equipment performance that proper application of pesticides can be obtained.

Appendix

Abbreviations

A.I.-active ingredient
A.I.A.-active ingredient per acre
EC or E-emulsifiable concentrate
F or L-flowable
GPA-gallons per acre
GPM-gallons per minute
MPH-miles per hour
PSI-Pounds per square inch
RPM-revolutions per minute
SP-soluble powder
WP or W-wettable powder

Weights and Measures

Length:
1 mile = 5,280 feet
1 mile = 320 rods
1 rod = 16.5 feet

Area:
1 acre = 43,560 sq. ft.
1 acre = 160 sq. rods

Weight:
1 pound = 16 ounces
1 gallon water = 8.34 pounds

Liquid Measure:
1 fluid ounce = 2 tablespoons
1 pint = 16 fluid ounces
2 pints = 1 quart
4 quarts = 1 gallon
1 gallon = 231 cubic inches

Speed:
1 mile per hour = 88 feet per minute

References

For equipment selection: Apply Pesticides Correctly, A Guide for Commercial Applicators. USDA and USEPA.