http://ipraudio.interlochen.org/OzoneVineyard_WEB.mp3
Fruit growers are constantly looking for ways to reduce chemical sprays that control insects and diseases. But they're slow to adopt a new practice until it's proven to work.
A vineyard in Leelanau County is one of the first to try a spray that produces no chemical residue and only pure oxygen as a byproduct.
Like Lightning
Naturally occurring ozone gas is produced when lightning flashes through the air.
A machine that creates ozone with an electrical charge mixes those bubbles of gas with water. That ozonated water has been used for years to disinfect containers in the bottled water industry. It kills things such as fungus and bacteria on contact.
"What you're basically doing is you're creating an environment that it can't live. And with ozone the beauty is that when you're done you get pure oxygen," says Bill Siegmund, owner of Pure Water Works in Traverse City.
Siegmund adapted an ozonator to ride on a trailer behind a tractor with a spray tank and a generator to keep the electric charge going. He's convinced ozonated water can replace some of the chemical sprays used routinely in vineyards.
"It's not that we're going to make a vineyard be able to become chemical-free. But as far as insect control, rust, blights, things like that, we're there," says Siegmund.
Skeptics
But he still has to convince growers. So far he's had one taker for a spray rig he's fabricated.
Some growers balk at the price tag of twenty-two grand. And they question whether this small prototype can be geared up for commercial use.
Jay Briggs says it would work well to spray a few acres. "Altogether with our vineyard here and our other vineyard we have 50 acres. That would take forever," he says. Briggs manages 45 North Winery in Leelanau County.
But here's the thing, ozonated water is already being used in wineries. Briggs uses it to sanitize equipment and to keep bacteria and molds out of wine barrels. So he was intrigued by the idea of using ozone to fight mildew and insects in the vineyard. And he set aside a small section of vineyard this year to test it. The results were surprising.
"I was just out there this morning walking around and I have zero fruit infection in the ozone. There's a touch of powdery mildew on leaves but at this point in the year, it's easily remedied," Briggs says.
Need More Tests
Now that's just an observation of one small section of one vineyard in one year. Not nearly enough to satisfy researchers such as Annemiek Schilder. She studies disease in wine grapes at Michigan State University.
She's open to the possibility that ozonated water may be a revolutionary technology. But she says first there needs to be several years of unbiased studies to prove it works.
"Maybe multiple locations, multiple seasons with different disease pressure. If you have disease pressure and it works it's much more convincing than if you have a year when there's not so much disease," Schilder says.
Without data, MSU Extension won't recommend the practice to growers. On the other hand, Schilder says, approved chemical sprays for grapes are very effective because they last a lot longer.
"You know, once they're on the leaf they are active for a week, fourteen days, sometimes up to three weeks. And they kill any incoming spores. And ozonated water, it dissipates almost instantly," Schilder says.
You'd have spray ozone virtually every day to get the same protection. That's not something Jay Briggs at 45 North Winery would even consider.
Try Again
Briggs doesn't expect ozonated water by itself will ever take care of the vineyard. But he does see potential, say, to knock back the first signs of mildew, for instance. And ozone can be applied a lot closer to harvest because it doesn't leave any harmful residue.
"I mean anything we have as a tool that can get us away from chemical dependency. I think it's a great addition to the industry," Briggs says.
He plans to set aside a regular section of the vineyard next year for a head-to-head comparison between ozonated water and commercial sprays.
And Annemiek Schilder, with MSU Extension, is interested in seeing the results.