Remember winter sprayer maintenance

Tony Nye - OSU Extension

We all know this is a busy time of year for many farmers, but taking time to winterize your sprayer now can payoff in avoiding problems next spring.

Without proper winterizing before the temperatures really drop, you could end up with a pump that is cracked and/or not working at its full capacity.

Dr. Erdal Ozkan, OSU Sprayer Technology specialist provides some important things you need to do with your sprayer this time of the year.

Most importantly, make sure to rinse the whole sprayer thoroughly before storing.

Rinsing the sprayer thoroughly after each use reduces likelihood of cross-contamination of products applied next spring. Insufficient rinsing may also result in clogged nozzles.

Once the nozzles are clogged, it is extremely difficult to bring them back to their normal operating conditions. Leaving chemical residues in nozzles will usually lead to changes in their flow rates, as well as in their spray patterns resulting in uneven distribution of chemicals on the target.

Depending on the tank, proper rinsing of the interior of the tank can be challenging. Rinsing is easy if the tank is relatively new and equipped with special rinsing nozzles and mechanisms inside the tank. If this is not the case, manual rinsing of the tank interior is more difficult, and poses some safety problems such as inhaling fumes of leftover chemicals during the rinsing process.

To avoid these problems, either replace the tank with one that has the interior rinse nozzles, or install an interior tank rinse system in your existing tank.

For effective rinsing of all the sprayer components, circulate clean water through the whole sprayer for several minutes with the nozzles off, then flush out the rinsate through the nozzles. Rinsing should be done in the field, or on a concrete chemical mixing/loading pad with a sump to recover rinse water.

Dispose of the rinsate according to on the directions on the labels of the pesticides in the tank. Always check the label for specific instructions

Rinsing the system with water as explained above may not be sufficient to get rid of chemicals from the sprayer. This may lead to cross-contamination problems.

Residues of some pesticides left in the sprayer may cause serious problems when a spray mixture containing these residual materials is applied on a crop that is highly sensitive to that pesticide.

To avoid such problems, it is best to clean and rinse the entire spraying system with cleaning solution. A mixture of 1 to 100 of household ammonia to water should be adequate for cleaning the tank, but you may first need to clean the tank with a mixture containing detergent if tank was not cleaned right after the last spraying job was done.

Some chemicals require specific rinsing solution. The University of Missouri has a publication listing commonly used pesticides and the specific rinsing solutions required of each, available online at:

Always check the product label to find out the most recent recommendations on cleaning agents.

Ozkan reminds producers that cleaning the outside of the sprayer components deserves equal attention. Remove compacted deposits with a bristle brush. Then flush the exterior parts of the equipment with water. A high pressure washer can be used, if available.

Again, the rinsate should be disposed of according to the label recommendations.

To prevent freezing, check one more time to make sure there is no liquid left inside any of the sprayer parts.

The pump, the heart of a sprayer, requires special care. After draining the water, add a small amount of oil, and rotate the pump four or five revolutions by hand to completely coat interior surfaces. Make sure that this oil is not going to damage rubber rollers in a roller pump or rubber parts in a diaphragm pump.

Check the operator’s manual. If oil is not recommended, pouring one tablespoon of radiator rust inhibitor in the inlet and outlet part of the pump also keeps the pump from corroding. Another alternative is to put automotive antifreeze with rust inhibitor in the pump and other sprayer parts.

To prevent corrosion, remove nozzle tips and strainers, dry them, and store them in a dry place. Putting them in a can of light oil such as diesel fuel or kerosene is another option.

Finally, find ways to protect your sprayer against the harmful effects of snow, rain, sun, and strong winds.

In addition, Ozkan suggests you check the condition of all sprayer parts one more time before leaving the sprayer behind. Identify the parts that may need to be worked on, or replaced. Check the tank and hoses to make sure there are no signs of cracks.

Check the painted parts of the sprayer for scratched spots. Touch up these areas with paint to eliminate corrosion.

Don’t forget to cover openings so that birds don’t make a nest somewhere in your sprayer, and insects, dirt, and other foreign material cannot get into the system.

Tony Nye is the state coordinator for the Ohio State University Extension Small Farm Program and has been an OSU Extension Educator for agriculture and natural resources for over 30 years, currently serving Clinton County and the Miami Valley EERA.

Tony Nye

OSU Extension