Researchers hope to create orchards that use more mechanical picking, sorting
By DAN WHEAT
A four-year, $3.9 million federally funded program to improve production and marketing of sweet cherries is on track after its first year, the project leader says.
"I'm enthusiastic about what's been accomplished, coordinating research and outreach among 11 principal investigators across four states. We've collaborated well as a team and with industry," said Matt Whiting, project lead and stone fruit physiologist at Washington State University Irrigated Agriculture Research and Extension Center in Prosser, Wash.
The researchers from Washington, Oregon, California and Michigan met Nov. 18-19 at The Dalles and Hood River, Ore. They talked about the first year, toured orchards near The Dalles where cherry fruiting walls are being developed and discussed the work ahead.
One objective is to create highly efficient orchard systems amenable to mechanical pickers, field sorting and field packing. Trial blocks of upright fruiting offshoots -- called UFOs -- have been planted in private orchards near The Dalles, Yakima and Zillah, Wash., and near Lodi, Calif.
UFOs are cherry trees planted at an angle for the leader to grow horizontally and the limbs to grow vertically up trellises to form fruiting walls that are easier to harvest.
Tree survival and growth rates are being assessed, and the emphasis is on learning how to fill spaces between trees on trellises quickly, Whiting said. Good uniform upright growth is key, he said.
Fruit from such trees will be picked in the second year, mechanical harvesting will be tested and full commercial production should be reached in five years, Whiting said.
Yields, quality and costs will be analyzed to estimate grower returns, he said.
Picker Technologies, of Bellevue, Wash., and Qin Zhang, WSU biological systems engineer, are studying the best mechanical means for harvesting cherries including a single impact, sudden vibration and shaking trees. In the first year, they have identified ranges of energy necessary to get cherries to drop from trees, Whiting said.
Since most mechanical harvesting technologies result in stemless cherries, WSU geneticists are trying to understand the genetic basis for abscission, the release of the cherry from the stem, Whiting said. A long-term goal is breeding new varieties for clean abscission and superior fruit quality, he said.
So far, Skeena and Selah are two varieties with good abscission, he said. A growth regulator can be applied to Bing cherries two weeks before harvest to induce abscission, and mechanical shaking can be used to harvest regular Bing trees that do not form fruiting walls, he said.
Growers who attended the meeting were concerned cherries bred for release will be able to hold on in the wind, said Tracie Arnold, project communication director. That will be taken into account, she said.
A goal, she has said, is to reduce hand harvest labor, which makes up about 60 percent of production costs.
First-year consumer surveys continue to support what earlier surveys have shown -- consumers don't mind, or even prefer, cherries without stems and will pay the same price for them as for cherries with stems, Whiting said.
Michigan State University is studying whether biodegradable packaging extends shelf life of fruit from the normal two to three weeks after picking to upper-end four to five weeks or beyond, he said.