AMES, Iowa — Taste the first fruits of Iowa State University's new apple crop at an upcoming open house Sept. 13, from noon to 2 p.m., at the Horticulture Research Station, 55519 170th St., Ames.
The open house will highlight many different cultivars available for purchase at local orchards, along with upcoming and heritage cultivars not yet released to the public. The event will feature informal orchard tours, a chance to ask questions, and doughnuts and Iowa-grown cider.
Acres of apples
Fruit specialist Suzanne Slack, an assistant professor of horticulture, “loves” apples. She grew up on an orchard in Pennsylvania and was attracted to work at Iowa State by the opportunity to revive the university’s orchard. Since she arrived in 2021, she’s increased apple production to 15 acres at the Horticulture Research Station, where she studies the potential of historical and new apple cultivars to adapt to today’s growing conditions and industry preferences.
Once a top apple-producing state, some of the apple cultivars developed at Iowa State became popular favorites in the early 1900s, such as the Chieftain developed by Spencer Ambrose Beach. Beach, chair of the Iowa State horticulture department from 1905-1922, was a founding member of the American Society for Horticultural Science and a prolific apple breeder.
The Armistice Day freeze of 1940 decimated Iowa apple crops, and many orchards were “polished off” over time by competition from other regions and the ascendance of row crops in the state. Iowa State apple breeding and testing also declined, and the university’s original orchard was eventually bulldozed after damage from disease and storms. Thanks to Professor Paul Domoto (now retired), the most promising heirloom varieties were regrafted to save their germplasm. Over time, they were moved to a new home at the Horticulture Research Station north of Ames, where more than 61 apple cultivars are currently growing.
Cultivar trials led by Slack focus on Midwestern varieties. They are tested for their productivity, resistance to pests and disease, cold hardiness and survivability, as well as how they adapt to trellis systems. Students are also involved, including horticulture doctoral student Olivia Meyer, who has worked on apple projects with Slack and others for the last five years, starting when she was a master’s student.
“We are looking at everything from how they do on a trellis, do they taste good, and do they make good cider? There are winners and losers, as we expected,” Slack said. “So far, two of the winners are old Iowa State cultivars, Secor and Joan. Both have adapted very well to trellising and have great potential for being grown commercially.”
“We also have the original Red Delicious that originated in Winterset in the trials,” Slack said. “It tastes way better than the modern version that has had much of its flavor bred out of it in favor of boosting attributes like its color and ability to be shipped long distances.”
Big differences
According to Slack, there are other big differences between Beach’s apples and the varieties being grown today, in addition to flavor.
Today, most apple growers are switching to high-density systems, often planting 2,000-4,000 apple trees per acre, about 18 inches to 3-feet apart, using dwarf rootstocks that depend on trellising for support. The new systems are easier to harvest and are more productive per acre. They also mature more quickly and have fewer problems with insects and disease, so require less spraying. Growers can expect a return on investment after about four years instead of eight years or longer for traditional apple orchards (even after considering the cost of a trellis system).
“Some apple varieties can adapt readily to being on a trellis, like Honeycrisp, which actually prefers trellising,” Slack said. “The physiology of some cultivars is limiting, like Granny Smith apples that do not produce as well on a spindle trellis, which is one reason it’s becoming less popular to grow.”
Slack's work focuses on adapting cultivars (and orchards) to a spindle trellis system that has become the standard in most of the country. “We’re still in the process of helping those interested in switching to trellising,” she said.
Supporting growers
Maury Wills, of Wills Family Orchard near Adel, is the current president of the Iowa Specialty Crop Growers Association. He credits Slack for being a responsive resource for growers who have questions, including about pest management.
Wills, who grows apples in organic and conventional systems, said he was initially uncertain about the benefits of trellising, considering it "less natural." However, as he has experimented with growing dwarf trees on trellis systems, he has found "there are many aspects of the high-density systems that appeal to me, including less climbing on ladders and the improved effectiveness of sprays, due in part to a narrower canopy.”
Benji Deal of Deal’s Orchard is treasurer for the specialty crop growers association and recently attended one of Slack’s field days. “Our family business has benefited from Iowa State’s support for apple growers for generations. Suzanne is helping carry on that work, and we have appreciated her extensive knowledge on growing apples for the Midwest, including how to manage fire blight, a big problem in this region of high humidity.”
Funding for Iowa State’s orchard and related research and support for the industry has primarily come from USDA’s multi-state Hatch program, “Improving Economic and Environmental Sustainability in Tree-fruit Production Through Changes in Rootstock Use” (NC140), support from recent “seed” funding from the College of Agriculture and Life Sciences and a specialty crop block grant from the State of Iowa.
Contacts
Suzanne Slack, Department of Horticulture, 515-294-0035, slacksuz@iastate.edu
Ann Y. Robinson, Agriculture and Life Sciences Communications, 515-294-3066, ayr@iastate.edu