Grant Supports Organic Apple Research
Release Date: 11-06-2006
The plum curculio is a nasty weevil: pimply, snout-nosed and hump-backed. By itself, this pest has been enough to drive many New England apple growers away from trying to grow their fruit organically.
And it’s not alone. Following the curculio, a bestiary of apple maggots, Oriental fruit moths, tarnished plant bugs, thrips, leaf miners and mites hungrily prowl. If that’s not enough, mildew, fireblight, bitter rot and other diseases attack many varieties of apples; the regional favorite, Macintosh, is particularly susceptible to scab.
In general, it is extremely difficult and prohibitively expensive to produce organic tree fruits in the East. And apples seem the worst of the lot.
Unless you are like Lorraine Berkett, a University of Vermont professor of plant and soil science.
"It’s the holy grail of organics," she says, walking toward a razor-straight row of new apple trees at the UVM Horticulture Farm off Shelburne Road. "If we can produce marketable organic apples in New England, we’ll be doing something that many growers say is impossible."
That’s exactly what she aims to do. With a $657,000 grant from the US Department of Agriculture, she and her colleagues are leading the only significant university research effort in New England studying organic apple farming, and one of only a few such efforts nationwide.
Berkett stops and points to two stands of apple trees, both still green against a curtain of orange and yellow maples. Here, this past spring, she, along with assistant farm manager Terry Bradshaw and others, started planting and grafting five varieties of apple trees on a nearly two-acre research plot.
In one block, 250 branchless stems, with trunks wrapped in white tape, are connected to aluminum rods and wires, stretching like leafy telephone poles across the field. In the other stand, 216 older trunks, many Macintosh, have been cut with a chainsaw and new varieties grafted onto each stump. These two stands represent the two major paths farmers could choose in pursuing organic apples: start with new trees or cut old ones and add disease-resistant stock on top.
With Honeycrisp, Zestar! (yes, the exclamation point is part of the name), Ginger Gold, Macoun and scab-resistant Liberty varieties — plus the two age categories, various soil amendments, irrigation piping, and differing spacing between trees — the researchers have a menu of variables that they can use to study the effects of organic treatments.
At the top of the treatment list is kaolin clay. The same stuff that’s used in toothpaste, this inert wettable powder leaves a protective film on the leaves and on the apples themselves. Discovered in the 1990s and accepted for organic use in 2000, it appears to control or at least fend off many apple insect pests — including plum curculio.
"We absolutely white-washed these," Bradshaw says, fingering the rough grey-green leaves of one of the older trees. And while you might expect that the clay would inhibit growth, research shows that this non-toxic coating actually increases photosynthesis by keeping trees cool on hot summer afternoons that would otherwise trigger the tree to shut down because of heat stress.
Combining this treatment with others, like sulphur and natural oils, the researchers expect that at the end of three years they’ll have enough data — and enough apples — to see if the impossible might be overcome. "In these new blocks we’re going to find out what are the challenges, and do what we have to do to manage these organically and sustainably," Berkett says.
They’re not hoping to find a single horticultural sword to strike down the curculio and other attackers. Instead, they are starting what they see as a nearly decade-long effort to test and combine numerous approaches that all meet the now-federally regulated rules of organic farming, and that would be successful in the marketplace.
"Let’s see if we can do it," Berkett says. "We’re recording effort and studying the whole system, which includes, of course, the costs and trade-offs of these approaches."
"There are organic alternatives to all the challenges growers face. It may be a matter of integrating them well," she says. "But we’ll see what the research shows."
Dollars to Donuts
Only 10 farms in Vermont are listed in the Northeast Organic Farming Association’s directory as producing apples and few of these are, well, ready to plop down on a teacher’s desk.
At Shelburne Orchards, about 6 of their 80 acres of apple trees are managed organically. "We do sell some pick-your-own and press some organic cider," says Rob Healy who has worked for Nick Cowles, the orchard’s owner, for 15 years. "There are some good ones. But if you hold an organic apple and a conventional apple you can tell which is which. They tend to be smaller, and they’ll be a little off... That’s a tough sell in the supermarket."
The UVM group is hoping to make that sale a lot easier.
"Our goal in this research," UVM farm manager Bradshaw says, "is to grow top-quality fruit for the fresh market. We won’t be satisfied with a whole boat-load of cider apples."
For full story see The Holy Grail of Ogranics from the View.