Moving Pears To High-Density

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Manifest Density

To understand why Clark Seavert, an Oregon State University (OSU) agricultural economist, is advocating the planting of much more densely spaced pear orchards in the Pacific Northwest, it’s best to back up a few years. In 2004, Seavert and a wide range of tree fruit industry people were meeting to discuss how to make the business more profitable for growers.

Out of that meeting came the Washington Tree Fruit Research Commission initiative, “The Technology Roadmap For Tree Fruit Production.” It was based on a simple, though bold, premise, especially in light of the fact that 2009 is already here: “For the U.S. tree fruit industry to compete globally, we must reduce the cost of production of its highest quality fruit 30% by the year 2010.”

Though Seavert was not instrumental in developing the Roadmap, he feels that the goal has been met, largely through the use of platforms, chemical and mechanical thinners, and better crop protection products. He also says it became abundantly clear that there was no way such a goal could be reached without reining in labor costs. That meant that traditional orchards, with large trees that required a lot of ladder use, were out. Growers were going to need orchards that could utilize platforms and, perhaps some day soon, robots. “We need orchard designs that will take full advantage of technology,” he says. “The future of the tree fruit industry is going to have to incorporate these new technologies.”

Fruiting Walls




Today, OSU Extension horticultural research technician Janet Turner and her colleagues are growing shorter trees — 8 to 11 feet tall, compared with the traditional 16-footers — that are three times closer together. Instead of the usual 300 trees per acre, there are more than 900. And they are grown more like a vineyard than a traditional orchard, with the trees grown flat against wire frames, hence the term “fruiting walls.”

The idea behind the intensified orchard design is not simply to increase yields; in fact, Seavert wishes growers would stop being so hung up on yields. The Technology Roadmap’s premise is not based on quantity, but on the highest quality fruit, or target fruit. “We need to get away from the idea that we need 80 to 90 bins per acre,” he says. “You only need 40 bins to the acre at 90% target fruit.”

Seavert emphasizes that “target fruit” doesn’t necessarily mean large fruit. It usually does, because a lot of buyers favor large fruit. But the key to that last sentence is that’s what the buyer wants. In other words, the customer is always right. “What if you’re growing for a neighborhood school? Your target fruit is smaller fruit,” he says.

Competitive Orchard System

For a grower to define his target fruit, he must know exactly how much money he’s making on a per-box basis, says Seavert. For most growers, that means getting their pack-out reports and examining them to determine on a block-by-block basis where the greatest profit lies. “Where are you making your money? We talked to a Utah grower who thought he wasn’t growing target fruit, but he was making money,” he says, then adds an economist’s punch line: “You’ll never go broke making a profit.”

Because of the cost of labor, most pear growers will find that means planting orchards more densely, with newer varieties on smaller trees. Seavert and his colleagues came up with the theory, called the Competitive Orchard System (COS), after analyzing the economic impacts of renewing orchards to accommodate newer technologies as well as other factors involving labor costs, such as the rising minimum wage rate. “A COS is about evaluation and management of established orchard blocks and establishing new blocks to be efficient and profitable,” he says. “Growers make at least a 15% return on their investment by growing 90% of their fruit as target fruit, which generates a profit over and above the production, harvest, packing, and marketing costs.”

To help growers achieve those aims, OSU is growing several varieties of dwarf pear rootstocks, says Turner, who is managing the trials. “Opportunities to grow a smaller pear tree that begins producing fruit in the third or fourth year have been thwarted by a lack of dwarfing, precocious rootstocks,” she says. “Therefore, we are testing rootstocks from around the world, as well as domestic clones, to find characteristics to create a more efficient orchard system.”  

David Eddy is editor of American/Western Fruit Grower, a Meister Media Worldwide publication.

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