The dating and mating game: how apple breeding at UMN works

After 114 years of apple success, the University of Minnesota breeding program discusses breeding logistics, the 100-year anniversary of the Haralson and new apple varieties.


Image by Courtesy of the University of Minnesota

“Triumph” is the newest apple breed the University has created.

by Lara Boudinot

The apple breeding program at the University of Minnesota has been a long-standing tradition that has brought the University much-deserved attention across the country. As apple season reaches its peak this October and new varieties begin to hit the shelves, it is time to understand what apple breeding is all about.

What exactly is apple breeding and how does it work?

James Luby, a professor in the Horticultural Science Department and the director of apple breeding research at the University since 1982, described the process as “the dating and mating game for plants.”

“Basically, through hybridization, we create new varieties,” David Bedford, senior research fellow in apple breeding, said. “In the case of apples, we take the pollen from one tree and place it on the flower of another tree.”

This process produces fruit with seeds that are then planted again as the offspring of the original two hybridized trees. However, each seed produces a different tree with more or fewer traits from each of the parent trees.

Think of it like human offspring, Bedford said. “The seeds are the tickets to the future for us.”

When the seeds are planted and the trees grow, each tree is tested for pre-selected characteristics to see if any of the traits are good enough to be marketable, said Maria Hartnett, a fourth-year student in horticulture science and an intern in the apple breeding program.

With an abundance of characteristics possible, how do the breeders choose which are most important?

“For an apple variety to be popular, it has to provide a wonderful eating experience for people,” Luby said.

Texture and taste are the main two, but disease resistance and the ability to handle cold are other traits the program selects for, Hartnett said.

Bedford said there are about 20 different characteristics they evaluate apples for and about 5,000 trees are planted each year. Out of the 5,000 offspring trees, about 10 are selected to go through further testing.

After years of testing, the tree that produces the best-fit apples is chosen to be cloned through grafting, a process in which pieces of the desired tree are snipped and placed on another tree’s root system to grow repeatedly in nurseries for future production of the new apple, Luby said.

Luby said apple breeding at the University started in 1878 but was off and on again until 1908 when it moved to its current location in the Horticultural Research Center.

From 1908 to today, the University has introduced 28 apple varieties, Bedford said.

One example, the Haralson, was introduced 100 years ago, according to Minnesota Hardy.

“Haralson was the number one apple in the state for 70-80 years,” Bedford said. “It was hearty and lived through the winter … it was the apple of its time.”

Honeycrisp takes the lead

“Although the Haralson was a Minnesota favorite, the Honeycrisp put our program on the map internationally. It was a big move forward for us as a program and for the consumer,” Bedford said. “I always say there are two categories for the consumer: before Honeycrisp and after Honeycrisp.”

Honeycrisp was a huge advance in crunchiness and juiciness, Luby said. It is now the third most-grown apple in the U.S.

“Once we found Honeycrisp it became the benchmark for what an apple should be,” Bedford said.

The recent push to combine horticultural sciences, agronomy and plant pathology into a single department could result in the apple breeding program changing. Both apple breeders and farmers are hopeful the change in the department will not impact their breeding program.

“Breeding is just trial and error, so being able to take the time to do that is really important,” Hartnett said. “Having the patience and trusting that what you’re breeding could be something potentially beneficial to the market is also needed.”

Bill Hein, a local apple farmer and owner of Straight River Farms in Faribault, Minnesota, has been growing only Minnesota apple varieties for 20 years.

“I think the breeding program has been important for apple development and the University,” Hein said. “I mean, there are Honeycrisp planted all over the world.”

Although the program is currently known for its success with Honeycrisp, the new varieties of apples produced could combine Honeycrisp traits with other characteristics for the consumer.

A new variety, a Triumph

The Triumph is a cross of Honeycrisp with Liberty from Cornell University, which produces a juicy, dense and firm apple with a tarter flavor than Honeycrisp, Luby said.

The Triumph will be a great option for those wanting to grow apples organically, Luby said.

“Its special trait is its resistance to the most common disease that apple growers see, apple scab, which is the most common reason apple growers spray trees,” Bedford said.

Bedford said the Triumph was released in 2020 to nurseries, but it could take a few years for the apple to hit the market in a significant way because it takes several years for trees to grow apples.

There will be a new apple released in spring 2023, but Bedford could not say much about it except that it has a “Honeycrisp texture with almost a fruity tropical flavor” and that it is “a beautiful red apple.”

Favorite apples of apple breeders, growers and caretakers

“I like SweeTango, it’s got a unique sweet sweetness and it stays firm,” Hein said.

Luby agreed, saying SweeTango is his favorite due to the flavor.

Hartnett said that although Honeycrisp is a classic, SnowSweet is her favorite with its crispiness and freshness.

“Honeycrisp was the original and is still the standard for texture. I think SweeTango is my favorite flavor,” Bedford said. “It’s a little more intense than the other ones, and I have to say First Kiss is my favorite for juiciness.”

As apple season closes, it is time to run to the farmers market or the Minnesota Landscape Arboretum’s Apple House to grab some Minnesota apples and keep an eye out for the Triumph.