Good Fruit Grower

May 15

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34 MAY 15, 2015 GOOD FRUIT GROWER F or a few years now, there's been a movement of sorts to change tart cherries from a tree fruit to a berry. A few growers have followed the movement, and some tart cherries have been successfully harvested with over-the-row berry harvesters also used with raspberries, blueberries, haskaps, and saskatoons. About 15 years ago, Dr. Bob Bors began the work of breeding bush-size tart cherry trees and harvesting them with a berry harvester on the northern Canadian prairie at the University of Saskatchewan. He has several vari- eties that are now commercially available, and growers there are adding cherries to make a trio of fruit—tart cherries, saskatoons, and haskaps—harvestable by the same machine in three separate seasons. Then, less than a decade ago, work began at Michigan State University, when Dr. Ron Perry located several growers willing to plunge ahead and experiment with planting, pruning, and harvesting Montmorency tart cherries from trees sized and shaped to fit into the throat of a berry harvester. About the same time, Dr. Brent Black began work with high-density tart cherry systems at Utah State University. Utah doesn't have a large fruit indus- try, but about half the industry is devoted to desert production of Montmorency tart cherries like those grown in Michigan, Washington, Oregon, New York, and Wisconsin. Black credits a tart cherry research symposium orga- nized by Dr. Jim Flore at Michigan State University with turning his attention toward high-density tart cherries. Black spoke to tart cherry growers during the Northwest Michigan Orchard and Vineyard Show in Traverse City in January. Most of them were dismayed to find they knew nothing about this researcher or his work, which could affect their region where half of the nation's tart cherries are grown. High density Black wants to bring to tart cherries the same advan- tages that apple growers obtained when they moved to high-density plantings. He envisions growing tart cher- ries in a continuous hedge, like blueberries, but thinner, like a fruiting wall. "The tree has to fit existing harvesters," he said. The blueberry harvester he works with has catching plates at the bottom where fruit drops after being shaken from the bushes by a rotating spindle with fingers that are agitated by a cam drive. The trees enter a tunnel that is 7.3 feet tall and 3.7 feet wide. The shaker height can be adjusted by about two feet, so at the highest setting, the tunnel is 10.5 feet high, with trunk space of 3.1 feet at the bottom. With a shorter trunk, the tree height would have to be shortened so the tree is about 8.5 feet tall. One setback to his work came when Blueberry Equipment Inc. (BEI) ceased manufacturing opera- tions last year. Over-the-row work is based on a similar machine built under the Korvan name by Oxbo. Advantages Some of the reasons Black sees for moving this direction include: —Equivalent or higher yields. Tart cherry orchards now need lots of alley space around trees to move the trunk shakers and catching frames. Alleys can be nar- rowed and trees planted closer together. Trees can be shorter, but less open space is needed at the bottom of the tree. In his test plots, he has planted trees 4, 6, 8, and 10 feet apart in rows 13 feet apart. "Thirteen feet is too far," he said. "We'll need alleys maybe 10 feet, or even closer." Utah growers shoot for higher yields than growers elsewhere, wanting around 10,000 pounds per acre. Last year, with yields at that level in his test plantings, the cherry volume overwhelmed the berry harvester, something that needs to be addressed, Black said. —Higher quality. Tart cherries tend to bear in an outer shell around an open center and need good light exposure to develop large fruit with high soluble solids and intense color. CHERRIES harvested as BERRIES A Utah researcher joins others who want to change how cherries are grown and harvested. by Richard Lehnert Cherries

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