Extension Communications
3614 Administrative Services Building
Ames, Iowa 50011-3614
(515) 294-9915
11/27/00
Contacts:
Mark Gleason, Extension Plant Pathology, (515) 294-0579,
mgleason@iastate.edu
Elaine Edwards, Extension Communication Systems, (515)
294-5168, eedwards@iastate.edu
Yard and Garden Column for the Week Beginning Dec. 1
Disease-fighting Apples
By Mark Gleason
Extension Plant Pathologist
Iowa State University Extension
As fall downshifts to winter, some Iowans are already thinking ahead to the pleasures of future growing seasons. These people are called gardeners. With imaginations that defy brown landscapes and sub-zero wind chills, they conjure up scenes of next year's flowers, fruits and vegetables. For gardeners, the anticipation of future gardening is better than a high-powered sun lamp as a wintertime antidote.
Planning a backyard apple orchard may be the ultimate expression of gardening optimism. An orchard is a long-term investment of your precious time and garden space, but well-managed apple trees can pay you back for decades. And if you love apples, nothing beats growing and eating your own.
Apple growing is not for everybody, or even all gardeners. You need space, at least enough for a few trees, and full sunlight for at least most of the day. Your soil ought to be well-drained and not too clayey. This requirement, unfortunately, disqualifies most people living in recently built housing developments, where the topsoil was probably scraped off and sold by contractors before the residents arrived.
But let's suppose you have the space, the soil and the interest in a backyard apple orchard. Where do you begin? Selecting good varieties is a logical starting point. The "right" apple varieties will depend partly on the climate. Suitable varieties should not only survive our harsh winters, but also produce ripe apples before frost catches them in the fall. For example, lots of Iowans like the taste of Braeburn and Granny Smith, but these varieties require such a long season that they often freeze solid on the tree before ripening.
Of course, you'll want varieties that taste good, too. Some people prefer a sweet apple, others prefer a tart apple, but most people agree that an apple should be juicy and have a firm texture.
Don't forget disease resistance when planning your mini-orchard. Iowa apples are attacked by several disease-causing fungi, which can reduce fruit yield and quality if ignored. Since backyard apple growers are often unwilling to spray fungicides every two weeks like most commercial growers, planting varieties with genetic resistance to disease make the most sense.
Disease-resistant apple varieties have gradually appeared in nurseries over the past two decades, but some showed up less than five years ago. Most of them are available through catalogs or garden centers. But which ones are the best choices for Iowa?
To answer this question, we planted a small orchard at the Iowa State University Horticulture Farm in 1993. Included are 13 disease-resistant varieties, 11 of which were bred in the Purdue-Rutgers-Illinois program and two in the Cornell University program. Since 1997, we've harvested the trees and evaluated the quality of the fruit.
Dr. Cheryll Reitmeier of the ISU Food Science and Human Nutrition Department raised a small army of volunteer "taste panelists" -- ISU students, staff and professors who like apples -- to comment on the color, texture, juiciness and taste of the disease-resistant apples. The testing was done over two years in a "blind" manner; in other words, the tasters didn't know which varieties they were sampling. They filled out rating sheets, rating each quality factor from "dislike extremely" to "like extremely."
We also did a "people's choice" test last fall at the Des Moines Farmers Market. With help from Brian Etchen of Iowa Orchard in Urbandale, we set out slices of five disease-resistant varieties grown at the ISU Horticulture Farm. We asked 175 passersby to sample the slices and rate the same quality factors as the ISU taste panels. We also asked them whether they'd be willing to buy the apples if they were available at a market.
Some clear winners emerged from all this testing. The varieties Liberty and Redfree yielded well and also were rated highly by the panelists. These two are especially attractive since they have multiple disease resistance -- to apple scab, cedar-apple rust and the dreaded bacterial disease fire blight. Redfree ripens in August, while Liberty typically ripens in late September.
At the Des Moines Farmers Market, the late-September variety Freedom emerged as the clear winner. Another taste favorite was Gold Rush. A limitation of Gold Rush is its late ripening date; for this reason, it's probably better suited for planting in the southern half of Iowa than in the northern half.
Does growing disease-resistant varieties mean that you can forget about all pest problems? Probably not, since insects will still bug your apples. But the disease-resistant varieties will make apple growing much simpler and cheaper. For more advice about successful backyard apple growing, get the ISU Extension bulletins "Fruit cultivars for Iowa" (PM 453) and "Growing fruit in Iowa" (PM 1788), available through your County Extension Office or ISU Extension Distribution (phone: 515-294-5247).
Planning your own apple orchard is a creative way to take a bite out of an Iowa winter. With a little help from genetics, in the form of Redfree, Liberty, Gold Rush and Freedom, you can grow all the fresh apples you want, and make pies out of the wormy ones.
ml: isugarden
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