Low input, organic, or biodynamic?
Grape growing must be profitable, regardless of the pest management style.
A panel discussion examining low-input, organic, and biodynamic grape growing found that while each takes a different approach to pest and nutrition management, there is a common denominator: if the practice doesn't work or isn't economical, the grower won't be in business for long.
It's hard to find a "true" conventional grape grower in Washington State nowadays, observes Washington State University's integrated pest management coordinator Dr. Doug Walsh. The state's grape industry has dramatically reduced its use of organophosphate insecticides. Many growers use minimal applications of pesticides not only to reduce their impact on the environment, but also to reduce costs.
Keith Oliver of Olsen Brothers, Inc., Prosser, said Olsen Brothers has adopted a low-input, low-spray volume mindset as a way to reduce costs in its various vineyards.
In Concord grapes, their spray program has evolved to be primarily a prebloom and postbloom leaf-feed spray. But after little evidence that the sprays were making a difference, he said they plan to end those this year. They typically have few pest and disease problems with their Concord grapes.
"Our plan is to do no spraying on Concords this year," he said. "That's the ultimate definition of low spray. You can't get much lower volume than that." In wine grapes, for years they used an airblast sprayer for foliar and fungicide sprays, applying 50 gallons per acre at the beginning of the season and spraying every other row at a speed of three miles per hour. As the canopy developed, gallonage was increased to 100 gallons per acre, and every row was sprayed. They tried further reducing spray costs by using a tower sprayer, but they weren't satisfied with the spray coverage when working in a full canopy.
About eight years ago, they bought a low-volume, two-row sprayer that allows them to use only 25 gallons per acre. Oliver said that they get great coverage and save in manpower and tractor hours. "And the gallonage is so low that we don't need to fill up as often as before."
Initially with the low-volume sprayer, they were applying chemicals at 70 percent of the label rate. Now, depending on the vineyard, they apply 50 percent, or lower, of the label rate, further reducing costs. He noted that sulfur doesn't work well in the low-volume sprayers, and for occasional mite flare-ups, they have to spray with a higher volume.
Because it takes them considerable time to get across all of their acreage for powdery mildew control, they follow the calendar and weather conditions to anticipate when fungicide applications should start. They also incorporate other sprays with a fungicide when possible.
"On a good day, when everything goes perfect, which isn't often, one man can cover about 70 to 80 acres with the two-row sprayer," Oliver said. "My pitch for low-volume is that we're doing things very cheaply without sacrificing yield or production."
Prosser grower Dan Dufault has farmed his Concord grapes organically for 18 years, apples and cherries for seven. He likes working with natural systems, but admitted that he originally switched from conventional to organic for "the lure of more money for my product," as well as the spiritual experience. "Now, I would never go back to conventional farming."
For grape mealybug control, Dufault released lacewings and a predatory beetle called the mealybug destroyer (Cryptolaemus montrouzieri) in the vineyard about ten years ago and hasn't had any mealybug problems since. The destroyers were inexpensive and cost $2.50 per acre, not including the labor of four workers needed to release the beetles.
Dufault said that the prices for organic Concords in recent years have been about 25 to 30 percent higher than for conventional Concords. "But that's not high enough," he said, explaining that production costs are significantly more per acre for organic than conventional.
"If I had to do it again, I wouldn't plant Concords unless you can figure out a different way to market the crop."
One option is to custom process the grapes yourself and market your own concentrate, he said. "We've done that before, and that might be something we go back to because we need more money for our grapes."
The whole point of biodynamic viticulture is to create a self-sustaining, healthy vineyard, said James Michael, who learned about biodynamic viticulture while he was marketing director for Momtazi Vineyard and Maysara Winery in McMinnville, Oregon. Moe and Flora Momtazi have 200 acres of certified biodynamic wine grapes, with another 80 acres planted that will become biodynamic. Michael is now back in his home state of Washington as a marketing representative for a wine distributor.
"The goal of biodynamic is to recreate the balance of nature on your own property," he said, adding that he plans to someday convert his family's vineyard in Prosser to the biodynamic system.
When growers apply nutrients and pesticides to the vineyard, he said the materials are taken up by the plant and fruit. "Slowly, but surely, you're diluting the terroir that you've got," Michael said. "Is it measurable? Who knows?"
But those who have participated in biodynamic wine tastings claim there is something in the biodynamic wine—an essence—that sets it apart from wines made from grapes grown conventionally or organically, he noted.
Michael said there was a marked difference in taste and grape quality between Momtazi's organic and biodynamic grapes sitting side by side in bins during crush.
He explained that while both biodynamic and organic farming use natural substances instead of synthetic chemicals, what sets biodynamic apart are the "forces," a key component in biodynamic practices. "When I mention 'forces,' that's when I start to lose people in my talks," he said, smiling.
The timing of applications of preparations that are prescribed for nutrition and vine health, is linked to the forces, or lunar cycles, he said. For example, if a foliar fertilizer is to be sprayed, plant uptake will be highest when there is the correct influence from lunar or celestial bodies.
Biodynamic farming is more labor intensive, he added, but it seems to be worth it financially for those who are doing it. There is demand for biodynamic grapes in both domestic and export markets, Michael said. "If it didn't pay, they wouldn't be doing it."
The panel discussion was part of grape industry talks presented last November at the Washington State Grape Society's annual meeting.