Research slices to problem's core
Physiologist works to overcome difficulties with high-profit Honeycrisp apple
By DAN WHEAT
If there's a problem child among apple varieties, it's the Honeycrisp.
It's a pain to grow and a headache to store. But growers and warehouses put up with it because when things go right it makes a lot of money.
Enter Ines Hanrahan. You can think of her as the Honeycrisp nanny. Maybe she can't correct Honeycrisp's behavior, but she wants to help growers and warehouse managers cope with it.
Hanrahan has an agricultural engineering degree from Humboldt University of Berlin, in her native Germany. She came to Peters Orchards in Wapato, Wash., 10 years ago on an internship, married neighboring orchardist Mark Hanrahan and got her doctorate in tree fruit postharvest physiology from Washington State University. She joined the Yakima office of the Washington Tree Fruit Research Commission five years ago and took on Honeycrisp.
Hanrahan, 35, conducted tests verifying research and a Honeycrisp storage regimen put forth by Jim Mattheis, research leader at the USDA Agriculture Research Service Tree Fruit Research Laboratory in Wenatchee. Last year, several warehouses successfully used Mattheis' plan. They stored Honeycrisp beyond Christmas, when normally they try to sell out of it.
Hanrahan is uniquely qualified to tackle problems of production and postharvest, Mattheis said.
"She has an ag background, is a tree fruit farmer and a scientist," he said. "If I had to be a farmer, I'd go bankrupt in a second. She has that practical experience in production and is a scientist."
The Mattheis regimen is to hold the fruit for one week after harvest at 50 degrees and then drop it to 36 degrees while keeping carbon dioxide at 1 percent and oxygen at 2 percent. By doing that, it can store for nine months.
Most varieties go immediately into cold storage, but Honeycrisp is chill sensitive and develops a soft scald or skin browning if it goes directly to a low temperature, Hanrahan said. However, the 50 degrees can cause bitter pit, so it only works on the best lots that have had the right nutrient management.
Too much carbon dioxide causes internal browning. Honeycrisp stays firm and crisp so it can be stored at 2 and 2.5 percent oxygen, higher levels than for most apples.
"Low oxygen puts apples in hibernation. You want them barely breathing," Hanrahan said.
Honeycrisp originated in the University of Minnesota's apple breeding program in 1974. It was released in 1991. For a long time it was believed to be a cross between a Macoun and Honeygold. Only recently was it discovered to be a cross between Keepsake and an unknown variety from the breeding program that's been lost, Hanrahan said.
Problem children can be even more problematic if one of the parents is unknown.
"It's a problem if you don't know the parent," Hanrahan said. "It's hard to track down why it's doing what it's doing."
Five or six years ago, Honeycrisp took off with consumers. They love its juicy texture, exceptional crispness and well-balanced flavor. The apple's University of Minnesota patent expired in 2008 and planting exploded in Washington state.
Honeycrisp fetches $45 to $50 per box wholesale, compared with $15 to $25 for other varieties.
In 2008, Washington shipped 1.8 million, 40-pound boxes of Honeycrisp. The crop is estimated at 3 million boxes this year. It could hit 7.5 million boxes in the next two to three years because of new plant-ings, estimated at 9 million trees through 2009, Hanrahan said.
"Some of the best growers in the state evaluated it early on and decided not to grow it because of all of its problems," Hanrahan said. "Now they kick themselves because they didn't know it would be so popular."
Now Mattheis and Hanrahan are focusing on how to determine the best Honeycrisp for storage. They suspect crop load and picking dates are key factors and are testing fruit grown with the same horticultural practices but from early, late and hot locations. They believe the best Honeycrisp for storage should have some remaining starch.
Could Honeycrisp's problems stem, at least in part, from not really liking its adopted home of Washington?
"We probably have some areas in the state better suited to grow it than others," Hanrahan said. "Because it was bred in Minnesota, it's adapted to cooler climates and that is the crux of the problem. It doesn't like it too hot, especially in the fall. It seems to do better in higher elevations."
Current home: Wapato, Wash.
Education: Agricultural engineering degree, Humboldt University, Berlin, Germany in 1999. Doctorate in tree fruit postharvest physiology, Washington State University in 2005.
Occupation: Researcher at Washington Tree Fruit Research Commission
Family: Husband Mark Hanrahan is a Wapato orchardist.
Quote: "I did not grow up on a farm, but had a grandmother who always had a big garden. I spent a lot of time with her. Every season on a farm is different and you constantly have to adjust. It never gets boring."