We’re getting close. Washington growers will plant the first commercial trees for the much-anticipated Cosmic Crisp apple in the spring.
To keep up with the excitement, organizers of this month’s Washington State Tree Fruit Association annual meeting in Wenatchee are dedicating nearly an entire session to the WA 38 apple, sold under the trade name Cosmic Crisp, the latest variety released by the Washington State University breeding program.
“It’s one of the first real releases from the WSU breeding program, so we really wanted people to get a lot of information about it so they can make informed decisions,” said Sam Godwin, a Tonasket, Washington, grower and chair of the annual meeting planning committee.
Topics for the Cosmic Crisp session, which is scheduled for Dec. 5, will include recommended horticultural techniques, licensing and marketing.
In addition to the convention, researchers have been holding well-attended field days to share the latest information on growing and storing the variety, while nurseries are ramping up propagation to make their first deliveries later this winter.
“The timing is important because a lot of people are making decisions about whether to get involved with the new variety,” Godwin said.
Still, the education will be ongoing as field trials continue to yield more results, orchardist Dave Allan told a group of fellow growers at a September field day near Prosser, Washington. Grade standards are a work in progress, too.
“We are trying a number of different systems, and some of them are going to work well and some are not,” said Allan, who ran some of the trial blocks at Allan Brothers’ orchards. “And we’re in the process of discovery.”
Count him in as a booster though. He predicts the apple will become one of Washington’s most successful. “I think we all agree with that,” he said. “If we’re wrong we’re all going to have to go to dumb school, but we’ll all get there together. But I think it’s going to be successful.” •
More Cosmic Crisp tips
Growers continue to glean tips and advice about growing the Cosmic Crisp as they prepare to plant the first commercial trees next spring.
Researchers held two field days in mid-September to give growers a glimpse of Washington State University’s newest apple on trees at harvest time. The visits followed similar field days in April shortly after bloom.
The Cosmic Crisp, or WA 38, was developed by the university’s apple breeding program and, in the United States, will be grown exclusively by Washington growers for 10 years.
Growers will start the first commercial plantings in 2017 with more to follow in the coming years.
Here are several points researchers made during three Washington field days in Prosser, Quincy and Wenatchee:
—Don’t thin Cosmic trees until you have a full crop after three years or so.
The tree tends to thin itself down to single pieces of fruit with few doubles and virtually no triples, while fruit helps control the growth of the vigorous variety.
Karen Lewis, a Washington State University regional extension specialist, said she learned the hard way with a hand-held string thinner at the Roza trial orchard in Prosser. “I over thinned because I didn’t understand that this variety, this cultivar, tends to thin itself down pretty easy,” she said.
—Avoid Manchurian crab apple pollinizers.
They share an allele in common with Cosmic Crisp, making them 50 percent incompatible. Researchers are searching for recommended pollinators specific to the Cosmic, but until then they advise using multiple sources, including Whitney crab and Snowdrift crab, and commercial varieties such as Granny Smith, Red Delicious, Golden Delicious or Winter Banana. Plant a pollinizer tree every 30 feet in every row.
—Cooling and shade is recommended but not essential.
The test blocks at Sunrise and Roza research orchards have no shading or overhead cooling and researchers are finding few sunburn problems. Commercial growers Stemilt Growers and Allan Brothers have used overhead cooling in their test blocks, which are several years older than the university’s blocks.
—Cosmic Crisp apples color well but sometimes develop green spot (shown above) in the stem bowl and shoulder during the summer heat.
“It’s an issue we don’t fully understand,” said Tom Auvil, a research horticulturist with the Washington State Tree Fruit Research Commission. They noticed the green speckling on fruit from the tops of the tree and on the larger fruit at Sunrise.
The blemishes often look somewhat like bitter pit but don’t reach as deep into the flesh of the fruit. However, green spot usually colors over and fruit color in general improves by the end of the season and even after harvest in storage.
“We dwell a lot on it because it is the only problem we see,” Auvil said. Buckskin color from heat stress also goes away, while none of the minor coloring concerns seem to affect the texture or taste of the fruit.
—Researchers have seen stem punctures, especially with fruit size 72 count and larger. That’s the same threshold where they notice an uptick in bruising, as well, Auvil said.
Consider clipping the stems that protrude from the stem bowl. It is frequently the longer stems on smaller fruit that create stem punctures on the big fruit, whose stems are often well contained within the stem bowl.
—Auvil recommended the following rootstocks for Cosmic Crisp propagation: Mark, Budagovsky 9, Geneva 41, G.11, G.935, and Malling 9-337. Bud 9 and Mark should be planted closer together than M.9, while G.11 does not like sandy soil.
—When planting young trees, Auvil recommends cutting feathers back to four to six buds and cutting the terminal 1 foot from the top of the central leader, “and then leave it alone until we have fruit.” Maintenance pruning on a strong bull sucker is good as long as it is only on the two or three strongest upright shoots, he said.
—Stay tuned for a six-scale starch chart to help plan harvest timing. Researchers are working on it, said Ines Hanrahan, project manager for the Washington State Tree Fruit Research Commission.
—The Cosmic Crisp stores well, with or without MCP, showing none of the common storage disorders, such as internal browning, chilling injuries, superficial scald, bitter pit and late sunburn development.
Cosmics tied with Honeycrisps in taste tests throughout the year until the last tasting in the spring, when tasters reported that Cosmics had better flavor, Hanrahan said. It also resists bruising.
—The Cosmic will split if left on the trees too long during harvest, which usually lasts about two weeks.
Harvest too late and risk up to 15 percent split. “Timely picking is still important,” Hanrahan said. “It’s not all magic.”
—Stefano Musacchi, WSU horticulturist and endowed chair in tree fruit physiology and management, suggested growers renew prune with short limbs to keep a narrow canopy and encourage fruit close to the trunk. However, when you need to remove one branch, leave a stub of at least 2 inches or it will dry out.
– by Ross Courtney