WSU Sweet Cherry Research Integral to Blossoming Industry
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Legend has it that the adolescent George Washington demonstrated
his honesty when he confessed to chopping down his father's lone
cherry tree. Today, one of his myriad namesakes, Washington State
University, is rectifying the Founding Father's youthful
indiscretion. WSU is demonstrating its commitment to state and
regional agriculture through research and marketing innovations in
support of the burgeoning sweet cherry industry - an industry for
which Washington is the nation's top-producing state.
Fondness for the fruit exhibited by Washington's dad hasn't
diminished over the centuries. In fact, acreage and production
rates of fresh cherries in the U.S. and the Pacific Northwest are
on the rise. U.S. cherry production was about 276,550 tons in 2004,
a 52 percent increase from 2002, according to the National
Agricultural Statistic Service.
A record crop in 2005 saw 12 million 20-pound boxes harvested in
Washington, Oregon, Idaho and Utah, according to the Northwest
Cherry Growers in Yakima. Part of this was due to increased
acreage, which, for example, has grown from about 25,000 acres in
Washington in 2000 to 30,000 acres in 2006.
With growth comes the need for labor, which already is in short
supply, according to the Washington Growers League. Because of
their small size and scattered distribution in trees, cherries are
known as the most labor-intensive fruit crop. But a sufficient pool
of future agricultural labor is doubtful, due to potential changes
in immigration reform and other issues.
Enter researcher Matt Whiting, WSU horticulturist at the
Irrigated Agriculture Research and Extension Center in Prosser.
Supported by a $40,000 grant from WSU's IMPACT (International
Marketing Program for Agricultural Commodities & Trade) Center,
he has worked with the Washington State Tree Fruit Research
Commission for three years to test a novel mechanical harvester
that could decrease the need for manual labor in the sweet cherry
industry. Preliminary testing has shown potential for the
mechanical harvester to reduce harvest costs by 80-90 percent.
Whiting's results were encouraging; 90 percent of the cherries were
removed from the trees and, of those, 88 percent were collected and
packaged. These levels are expected to increase if trees are
trained to be more accessible to the mechanical harvester - what
Whiting calls "matching biology with technology."
But there may be a glitch. The harvester results in cherries with
no stems. And that raises at least two questions: 1) does the shelf
life of stemless cherries meet or exceed that of cherries with
stems; and 2) will the public buy stemless cherries?
Hung up on stems?
Results so far show that 39 percent of consumers prefer the
stemless cherries. That figure is from a study of 200 consumers in
Calgary, Alberta, funded by the IMPACT grant and conducted by
IMPACT fellow Jill McCluskey, associate professor in the
School of Economic Sciences. The average price these customers were
willing to pay for stemless cherries was $3.47 per pound.
In order to mechanically harvest cherries, a plant bioregulator
must be sprayed on before harvest to loosen the stem-fruit
junction. But 57 percent of the Calgary consumers surveyed said
they are worried about the long-term effects of pesticides in
agricultural production. The plant bioregulator involved - ethylene
- is not a pesticide but a naturally occurring gaseous plant
hormone. But it still could affect consumer decisions to buy
stemless cherries, McCluskey said.
However, that could depend on how the information is presented. She
noted that pears also are treated with a ripening agent, and they
have not experienced a negative consumer reaction.
McCluskey plans to collect and interpret more data to more
accurately examine consumer response.
Meanwhile, new Ph.D. student Erick Smith is working with
Whiting to evaluate the shelf life and postharvest characteristics
of stemless cherries.
While others at WSU have done research pertinent to the shelf life
of cherries - for example, Eugene Kupferman in Wenatchee,
Michael Willett and Gary Apel in Yakima, and B. W.
Poovaiah in Pullman - there have been no similar investigations
for cherries without stems. Whiting's team will collaborate with
John Fellman, professor and scientist in Horticulture and
Landscape Architecture.
Improving varieties
Stems and shelf life are two factors that influence consumer
interest in sweet cherries. Others include cherry variety and
growing season.
While Bing cherries were the dominant variety 10 years ago, today's
growers are planting cherries that have been selected for being
either late bearing or early bearing in comparison to Bings,
Whiting said. He directs a sweet cherry variety breeding program
initiated two years ago with funding from the Washington Tree Fruit
Research Commission that evaluates, among other characteristics,
harvest timing for more than 70 varieties and experimental
selections.
Adding new varieties and planting at higher elevations has led to
an 11-week harvest, and longer consumer season, compared to the
traditional four-week harvest, said Roger Pepperl of Washington's
Stemilt Growers, the largest sweet cherry packing/shipping
organization in the world.
Rootstocks also are changing, Whiting said. Many new orchards
planted in Washington use new varieties grown on rootstocks that
induce fruiting within three years from planting, compared to five
years on the old rootstocks. The new rootstocks also reduce tree
size, which means more trees (and fruit) per acre and, most
important, easier and less-expensive harvesting.
WSU's support of the cherry industry doesn't end at production and
harvest. Pricing and marketing research also is a valuable
contribution. The total market value of fresh cherries in
Washington was $236 million in 2004.
Thomas Marsh and Thomas Wahl have developed a
straightforward model to predict the wholesale price of fresh sweet
cherries. The model is what economists know as an inverse demand
system.
"With help from IMPACT funding, we also identified key factors
important to cherry pricing," Marsh said. They found that the
amount of cherries produced in each state, as well as the amount
supplied to domestic and international markets, explained most of
the variation in the annual fresh cherry price for Washington,
Oregon, Utah and California.
The full paper discussing price influences, as well as the formula
developed to estimate cherry prices, can be obtained by contacting
Marsh at tl_marsh@wsu.edu.
In their study, the amount of cherries produced in each state had a
smaller effect on price compared to the quantities supplied to
foreign markets. In other words, if U.S. farmers produced more,
prices domestically would not necessarily go down much. But the
role of international markets can markedly affect cherry prices,
the study found.And the international influence is expected to
increase. Iran and Turkey are the top world producers of sweet
cherries, but they are not significant competition to the No. 3
United States - yet, according to Whiting. Because of their short
shelf life and the challenges of growing and packing, sweet
cherries mostly are consumed domestically. But as growing, handling
and shipping technologies improve, Whiting predicts these countries
and China will become strong competitors, especially because they
are closer to key export markets in the Far East.