The Rock Doc — Bringing a new apple to stores everywhere


When I was young my family ate a lot of Red Delicious apples. Some came out of my trusty lunchbox at school, some were straight from the refrigerator at home. The apples were big and eye-catching, but in my opinion they left something to be desired in their eating qualities. Still, they gave us a reasonably economical and convenient fruit choice, and we were glad to have them.

These days there are lots of options in the stores when it comes to apples, from the traditional varieties like Red Delicious, Jonathan and McIntosh to newer varieties like Honeycrisp and Jazz. Depending on how sweet or tart you like your eating apples, and how firm or how crisp you prefer them, there are a range of options available in many grocery stores.

Where do all these varieties come from? The answer is that there are horticulturalists always at work doing the labor necessary to breed better apples that span a wide gamut of qualities. These days that means scientific breeding done at agricultural research and extension centers.

Recently I met with Prof. Kate Evans of Washington State University. Evans breeds apples for the growing conditions of central Washington State, a powerhouse region of the country for apple production. She very kindly brought samples of one of her new apples, currently known by its patent name as “WA-38.”

Naturally I jumped right in by taking a bite of the new apple. I would describe WA-38 as juicy, firm and crisp. It’s tarter than Honeycrisp, which in my world is a good thing. Its texture is different, too.

“It stays crisp in the mouth longer than Honeycrisp,” Evans said. “Texture is a tough quality to describe, but that’s one way of putting it.”

The WA-38 apple is the result of traditional breeding.

“We did use some DNA-informed selection,” Evans said, “but it’s not a GM product.”

The apple resulted from crossing Honeycrisp with an apple called Enterprise. The first step was taken in 1997 when researchers collected pollen from Honeycrisp and pollinated flowers of Enterprise. During that growing season, the flowers ultimately became fruit with seeds embedded in them.

“All the seeds are like siblings in terms of the degree of relatedness they have,” Evans said. “So there is variation in the genetics from seed to seed, and therefore in the properties of the tree and fruit those seeds will ultimately yield.”

Researchers like Evans take seeds, chill them to imitate winter conditions, and then germinate them in the greenhouse. Young seedlings then grow up.

“Right now I have 24,000 seedlings growing in the orchard,” said Evans. “We keep an eye on them all, taking samples from the ones that catch the eye.”

Breeding apples is partly a matter of generating variation and then selecting the best plants at each stage of the cycle.

“It takes 5-6 years to go from the first seed of a new variety to having fruit-bearing trees of that type,” Evans told me. “In total, it takes around 18 years for the full variety development due to the several rounds of testing required before release.”

Horticulturalists can take a bud of the new apple tree and graft it onto a rootstock. That technique is called vegetative propagation and it dates back to ancient times. It allows growers to combine the best qualities of the rootstock variety, in terms of roots and trunk, with another apple, in terms of fruit actually yielded.

To be worth the effort of breeding, an apple has to have many good qualities. These days those include good storage properties because the apple industry wants fruit that it can sell 12 months per year. The apples also need to resist bruising, Evans told me.

Today, 16 years after the original cross of Honeycrisp and Enterprise, WSU is ready to move forward with the next step of ultimately bringing WA-38 to market. The university is looking for a licensee to manage the process of taking the variety to the industry and then to consumers.

Along the way a name for the new variety will be dreamed up.

“It will be catchy, something that will appeal to consumers in the grocery store,” Evans said.

Just for fun, I’m trying to think of suggestions. If you dream up something good, feel free to send it to me at epeters@wsu.edu. I’ll pass it along to the right folks.

Dr. E. Kirsten Peters, a native of the rural Northwest, was trained as a geologist at Princeton and Harvard. This column is a service of the College of Agricultural, Human and Natural Resource Sciences at Washington State University.