Last week I visited with everyone about rinsing and draining your sprayer equipment. This week I would like to go more in depth regarding the actual cleaning of your equipment.
After your sprayer has been rinsed and drained, it’s time to clean or decontaminate it. Be sure to decontaminate both the inside and outside of the machine, running liquid through the boom and out the nozzles. You don’t need to fill the sprayer, just use enough cleaning solution to completely fill the lines and provide enough agitation. When you are scrubbing or washing the equipment, please wear your personal protective equipment because of splash-back potential.You will need to select your cleaning agent based on the pesticide and its formulation. Please note that not every pesticide asks for the same cleaning agent. The best cleaning agent for different types of pesticides can be found in the Extension MontGuide titled, “Maintenance, Cleaning and Storage of Ground Sprayers” but do include ammonia, powder detergents, and activated charcoal to name a few.
Some tank cleaning agents and ammonia solutions raise the pH of the rinsate solution, making some products such as SU herbicides more water soluble and easier to remove from internal sprayer parts.
Chlorine bleach solutions hasten the breakdown of SU’s and some other herbicides into inactive compounds. However, chlorine is less effective at dissolving and removing those SU residues from spray tanks than ammonia solutions. Never add chlorine bleach to ammonia or liquid fertilizers containing ammonia as the two react to form toxic chlorine gas.
Fuel oil or kerosene is effective for removing oil-soluble herbicides. The fuel oil or kerosene should be followed by a detergent rinse to remove the oily residue. Also, run cleaning solution throughout the sprayer, including the agitation system and the return lines. Then rinse the system with clean water. Open all the nozzles until they are spraying pure water.
I would encourage you to contact your local county Extension office for further questions about sprayer maintenance and cleaning.