Extending the cherry season

Kiona (PC 8007-2) was recently released by Washington State University. It matures a little before Tieton.

The Dalles in Oregon is a unique tree fruit production area in that its orchardists grow cherries and very little else.

"We grow cherries, and that’s about all we grow," Oregon State University Extension educator Lynn Long, said during the annual Cherry Institute meeting in Yakima, Washington, in January. The Dalles, in the Mid-Columbia region, has about 8,500 acres of cherries, and fewer than 200 acres each of apples and pears. Most growers have at least 200 acres of cherries, and a couple have as many as 1,500 acres.

"I don’t know of any other industry in the United States, or any place around the world, that has this type of production scheme," Long said.

But this almost exclusive focus on cherries means that growers have to find ways to spread out the harvest period by having orchards at different elevations and planting different cherry varieties. Most growers have at least six varieties, and some more, Long said.

In the last few years, Oregon’s Mid-Columbia region has had more rain near harvest than neighboring Washington has, so growers have become more interested in crack-resistant varieties, such as Attika and Regina.

Long has been evaluating cherry varieties and rootstocks for the past 15 years and manages a variety trial with more than 50 varieties and selections from around the world. He offered the following observations:

Chelan: Long considers Chelan to be the best early variety in the Pacific Northwest. "If you grow it right, you can sell it," he said. "It’s not a big cherry and it could use more flavor, but it’s a cherry I think will be around for a long time to come."

Tieton: Many of the Tieton trees planted in the Mid-Columbia region are on Mahaleb rootstocks, and growers are starting to see some problems because Tieton is not very productive. In addition, in 2006, there was a lot of doubling, "and the flavor is not all that great," he added.

Kiona (PC 8007-2): Long has had this variety from Washington State University, Prosser, in test plots for a couple of years and said he likes the variety. It matures perhaps a day or two before Tieton but gains sugars early, somewhat like Brooks. Even before it colors up, the internal quality might be good enough to put on the market if consumers will buy a cherry that’s not the typical red, Long said. One of the concerns about Kiona is that in the test block it suffered severe frost damage while other varieties withstood the frost well. He recommends planting the variety on a productive rootstock, such as Gisela.

SPC 136: Long has been impressed with this selection from the Summerland breeding program in British Columbia, Canada, which has not yet been released. It ripens about the same time as Tieton or a couple of days later. It has excellent flavor and good fruit size and seems to store well. He recommends planting it on a productive rootstock such as Krymsk or Gisela.

Benton: This is proving to be a high-quality cherry with excellent flavor. When many varieties in his test plots had extensive doubling in 2006, Benton had much less. However, it appears to be much more prone to frost damage than other varieties. It blooms late—four or five days after the Bing. Long ­recommends a Gisela rootstock.

Cowiche (PC 7903-2): This variety was recently released by WSU, but Long has been tracking it for a number of years. "If you harvest it before it’s ripe, it’s a very sour cherry," he said. "If you wait until it’s ripe, it has a good balance of acid and sweetness. That’s exactly what consumers are looking for—a cherry that has high acids and sugars." However, it tends to develop pitting, but Long said it might be a case of figuring out when is the best time to harvest the cherry.

Attika: This variety is widely grown in Europe, and several new plantings have been made in The Dalles recently. "Those growers who’ve had plantings for several years have done very well in selling Attika and shipping overseas," Long reported. It is resistant to cracking. In the wet season of 2005, there was about 5 percent cracking in Attika compared with about 40 percent in Skeena in the same blocks at the same time. It blooms late, and one of the concerns that growers have had with the variety is susceptibility to frost damage. However, it came through frost in The Dalles with less damage than Benton or Kiona. Long said the variety ships well. One cherry producer in The Dalles reported that its Attika and Regina cherries arrived in the United Kingdom with fewer defects than Lapins. Sweetheart developed the most defects during shipping.

Selah: WSU released this variety at the same time as Benton. Growers are just starting to plant it, and there is still much to find out about the variety, Long said, though his initial impressions are good. It is moderately productive and matures about the same time as Lapins, but doesn’t produce fruit in clusters like Lapins. It produces large fruit and its susceptibility to cracking is about the same as Bing’s.

Lapins: Lapins is the second most important cherry variety in the region, accounting for 17 percent of total production. However, it is prone to wind damage when grown in the Mid-Columbia, so packouts are low. In 2006, because of pitting problems over a number of years, buyers for Oregon Cherry Growers refused to take Lapins as a fresh variety, Long reported. Alternative markets had to be found for the variety, and growers received much lower prices.

Long said Dr. Juan Pablo Zaffoli, a researcher at the Catholic University in Santiago, Chile, has said he feels that U.S. cherry growers pick their Lapins and Sweetheart too late and that is one reason for the pitting. Zaffoli also thinks it is related to crop load and an improper leaf-to-fruit ratio. The more balanced the crop load, the less pitting there is. Long recommends growers prune both Lapins and Sweetheart very hard, as they are productive varieties and can overset even on Mazzard rootstocks. "Let’s prune them hard, and hopefully we can reduce the amount of pitting we’re getting with both these varieties," he said.

Skeena: This variety produces high-quality cherries with a strong flavor. "I don’t think it’s the best flavor in the world, but it’s strong," Long commented. It is susceptible to cracking and it matures late, so young trees especially are susceptible to heat. He does not recommend that growers train Skeena to a central leader- or spindle type-system because the fruit is too exposed. A multileader ­system, such as the Spanish Bush or Kym Green Bush, protects the fruit better.

Regina: Regina is being widely planted in The Dalles. It is resistant to cracking and has generated good returns for growers, with no adjustments. "I think one of the reasons growers have shied away from Regina, especially in Washington, is because of its low productivity, particularly on Mazzard," Long said. He recommends G.6 or G.12 as a rootstock. Because it blooms very late, Sam, Schneiders, Starks Gold, Hedelfingen, or Attika are recommended as pollinizers.

Sweetheart: This is the best late variety available, in Long’s opinion. The Summerland breeding program has released three varieties that mature even later than Sweetheart—Staccato, Sovereign, and Sentennial—but they are not likely to be made available to U.S. growers in the near future, he said. He has had Sovereign in test plots since 1996 and likes it better than Staccato. It has better flavor, is less prone to mildew, and responds better to August heat. Sweetheart should be harvested at the light mahogany stage and should be pruned hard to keep the leaf-to-fruit ratio in balance to avoid pitting.

Asked about Santina, an early variety that matures about the same time as Tieton, Long said he felt there were better alternatives. "It’s a very bland-tasting cherry—worse than Tieton," he said. He’s seen high rates of cracking with Santina, also. "I think both Kiona and SPC 136 have better potential than Santina."