Purdue Extension weed control specialist Bryan Johnson asked a crowd of farmers if any of them had an air system to clean out spray volume remaining in the booms after emptying the tank. Only one hand went up. He wasn’t surprised. Only a few sprayers have this option, but it’s a viable way to clean booms if your sprayer has it.

The Miller sprayer that Pete Illingworth operates at the Purdue University Throckmorton Research Farm is equipped with such an option. Instead of using water, an air compressor produces compressed air to clean out the spray left in the boom.

“It’s a handy option,” Illingworth says. “This sprayer also uses the air tank for other functions on the machine.”

Fred Whitford, director of Purdue Pesticide Programs, says if your sprayer has the option, you still need to make sure you use it in the right way. “You don’t want to let the sprayer sit still in the barn lot as you empty the boom with air,” he says. “You need to drive over the field where you have sprayed and empty the boom, just like you would if you were using rinse water from the start.”

The air system also doesn’t give you an excuse not to triple-rinse the tank, he says. You still need to follow the triple-rinse procedure outlined on the label for most herbicides.

The farmer who raised his hand at the meeting where Johnson spoke had actually built his own air compressor system, rather than buying it as an option for his sprayer.

“There are some of those homemade units around,” Whitford says. “The only caution is that you still need to make sure you aren’t emptying the liquid spray volume from the booms onto one spot in the barn lot.”

AIR CLEANS BOOM: This Miller sprayer is equipped with an air compressor. Air can be used to clean out spray left in the boom after the tank is empty.