No one fell asleep during the environmental safety session at Remke Farms near Harlan, Ind., recently. No one dared to nod off. After all, Fred Whitford had the microphone! After working as a state regulator in a different state during what seems like another life, Whitford’s specialty is putting people on the spot, attempting to get answers from them.

But in the end, it’s to make a point, not to embarrass anyone.

Whitford, director of Purdue University Pesticide Programs, talked at the Seeing Green: Fields and Profits Soil Health Field Day sponsored by the Allen County Soil and Water Conservation District. His mission was twofold: to convince growers it’s imperative to clean out their sprayer before switching chemicals, and to demonstrate that many don’t clean them out as thoroughly as they think they do.

With all the fuss about dicamba herbicide this summer, and with a sizable number of growers saying they’re going to spray this fall, Whitford hit the mark on timeliness of his topic.

Brass tacks
Whitford walked right over to a farmer seated at a table. “Do you always clean your sprayer screens out?” he asked, glaring at the farmer. What was the poor farmer supposed to say? He finally managed to say that yes, he cleaned out his screens when switching chemicals or cleaning out the sprayer for the final time in a cropping season.

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Whitford wasn’t finished. “Are you sure you clean every screen out?” he continued. “Do you clean every screen out every time?” The grower was slow to answer.

The truth is that most people likely don’t clean every screen out every time, Whitford says. But after researching this topic for two years, he insists that something as simple as cleaning all screens out ought to be done every time you clean the sprayer.

“What happens is that say you don’t get as good a job of mixing chemicals in the sprayer tank as you like,” he explained to the field day crowd. “The material which may form from those chemicals likely ends up in the screens. If you empty out a screen that you haven’t taken off for some time, you’re going to bring out material that you’ve never seen before.”

Dirty nozzles
“How often do you clean your nozzles?” Whitford asked someone else in the crowd. All but that one person was glad he wasn’t asking them!

“Every nozzle needs to come out and be cleaned under pressure,” Whitford said. “It takes pressure to get out everything that might be in a nozzle.

“The other option it to buy a second set of nozzles which are matched to the product you’re spraying and carry them with you.” If you don’t want to take time to clean out the dirty nozzles right then, and do it properly, then switch them out for new ones, he added.

You can clean the set of dirty nozzles as soon as you have time, Whitford said. Continuing to spray with dirty nozzles that are experiencing plugging problems is not a smart option, he insisted.