Keith Roberts

Keith Roberts, senior vineyard manager for Wente Family Estates in Greenfield, California, has been intrigued with electrostatic sprayers since he first heard of the technology more than two decades ago.

Not until 2012, however, did Roberts take the plunge and purchase an electrostatic sprayer from On Target Spray Systems.

Why the long wait?

“I remember looking at some of the electrostatic sprayers and being curious, but the On Target unit was the first one that I thought was dependable enough that I wanted to try it,” Roberts said.

What most intrigued Roberts about the technology, and what he most enjoys today, is that he can treat three and four times as many acres between tank fills with an electrostatic sprayer than with a conventional sprayer.

“If you take a conventional sprayer and you’re filling it five times in a day, and it takes a half-hour each time, that’s five times the half-hour that you lose per day. With the On Target sprayer, we fill it up in the morning, then we fill it up at lunch and it runs the rest of the day.

“And as for coverage, it is doing as good as or better than the conventional sprayers, with one-quarter the amount of water,” he said.

“Still,” he said, “if it wasn’t reliable, it wouldn’t work. But the On Target unit has proven to be quite reliable.”

On Target Spray Systems, based in Mount Angel, Oregon, utilizes the law of attraction in its advanced technology. With tiny electrostatic charges, the system atomizes, or positively charges, droplets that are attracted to the negatively-charged, or grounded, surface of a plant.

Also, because the droplets are positively charged, they repel one another and will not collect into large droplets that can run off plant material onto the ground. Spray from an On Target sprayer emerges from the system’s patented nozzles as a mist that evenly coats the fronts, backs and undersides of plant material, forming a bond that protects plants from disease and insect pests.

The system is similar to the technology used by car manufacturers to powder-coat cars with paint.

One key difference between On Target sprayers and other electrostatic sprayers is the On Target units are engineered to minimize opportunities for major spray mishaps, Roberts said.

“With the On Target unit you’ve got (electrostatic modules built into) individual heads,” Roberts said. “So, if you happen to lose one, it is not going to cause you a major spray-application issue. With a lot of the other units, if you lose one electrostatic module, you’ve lost the whole rig.

“That was the downside, and it drove me away from the technology all those years, even though it seemed like the right thing to do,” he said.

With three years of positive experiences with the On Target sprayer under his belt, Roberts, who manages 900 acres of wine grapes for Wente Brothers, said he now is documenting exactly how much the sprayer saves in labor, fuel and other costs to help determine if it is cost effective for the company to purchase more.

“It appears at this point that it makes sense (to buy more units),” he said, “but we now are just making sure the documentation supports that decision.

“I do know that the On Target unit is reliable,” Roberts said. “I think it is a great tool, and we’ve definitely integrated it into our system, and we have no plans to pull it out of our system.”