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Oregon State University Agricultural Research updates

Puffy sinuses, droopy feathers: A fowl cold?

An OSU professor with a specialty in chicken diseases has diagnosed the first case of the "chicken cold" in Oregon.

In the fall Masakazu Matsumoto, a professor in the School of Veterinary Medicine, who conducts research through OSU'S Agricultural Experiment Station, diagnosed the first known Oregon case of a disease called infectious coryza.

Illustration of a sick chicken.

Illustration: Tom Weeks

The disease mimics a human cold, infecting the chicken's upper respiratory tract. Its inflamed sinuses cause its face to swell up and makes breathing difficult. The disease can spread quickly through a commercial chicken operation.

Although it runs its course in a few days, the sick chicken's egg production can fall off by 50 percent during its illness, cutting profits.

The disease is common in warm-weather climates such as California and Central America, where insects are suspected of carrying the disease. But up until now, Oregon's colder climate has prevented the fragile bacteria from surviving this far north.

Or so Matsumoto thought until a woman from Eugene brought in a sick chicken to Dr. Stanley Snyder at OSU's veterinary diagnostic laboratory.

Matsumoto developed the first vaccines against infectious coryza in the 1960s. He immediately recognized the disease in the Eugene chicken.

Now he is asking backyard chicken growers to be on the alert for the disease in hopes of keeping it out of Oregon's $50-million-a-year egg production industry.

It costs only about 5 cents per chicken to vaccinate chickens against the disease, but the vaccine must be administered by injection. The labor costs of catching and injecting 120,000 chickens in a commercial growing operation add up, Matsumoto said. The cost can make the difference between profit and loss in a marginal operation.

Matsumoto urged owners of chickens to buy only vaccinated or disease-free stock from a reliable dealer. And if they do observe the disease, he invited them to call him to report it at 541-737-2901.

Clones promise to resist virus

Genetically altered clones of popular potato varieties could be the ticket for potato producers looking for built-in resistance to potato virus Y, notorious for taking a toll on potato yields.

Illustration of waving potatoes.

Illustration: Tom Weeks

Tests at OSU branch experiment stations show the clones, which could be released for grower use in five years, can save up to 40 percent of yields lost to virus disease.

"Even though our tests show the clones yield about 10 percent less than standard varieties, that's a lot better than a potential 40 percent loss," said Steve James, research agronomist at OSU's Central Oregon Research Center, headquartered at Madras. James is coordinating the virus project.

Perhaps more important than the impact on yields, according to James, is that the clones might allow growers to reduce pesticide use and spend less money on production.

Potato virus Y is primarily spread by aphids. "Currently, growers spend $100 to $200 per acre on insecticides to control the aphids," James said. "Growing PVY-resistant clones would reduce pesticide applications and put that money in growers' pockets."

At the Center's Powell Butte branch, James receives clones developed by former OSU microbiology researcher Bill Dougherty. James increases seed for research trials and screens the potatoes for agronomic characteristics. "We want clones with good yield, tuber size and tuber quality, in addition to having resistance to PVY," James said.

Research trials on clone yields, quality and virus resistance are also being run by OSU researchers Dan Hane, an agronomist at OSU's Hermiston Research and Extension Center, and Ken Rykbost, superintendent of OSU's Klamath Experiment Station.

Under scrutiny are genetically altered versions of Russet Burbank, Russet Norkotah and Shepody potato varieties.

Eleven genetically altered Norkotahs, two Shepodies and ten Russet Burbanks have been put through tests at the three OSU branch experiment stations and at a University of California facility at Tulelake, Calif.

Scientists eye case of the missing middle-aged trees

Imagine a world without adolescents. Not bad, you might say, but what about a world that doesn't even have many middle-aged residents?

A "belt" from eastern Oregon down into Nevada has a perplexing population of young and old juniper trees with little in between. While junipers can live to 1,600 years or older, 97 percent of the trees in the area are less than 100 years old.

Researchers at the Eastern Oregon Agricultural Research Center in Burns, operated by OSU and the U.S. Department of Agriculture's Agricultural Research Service, are tracking this population trend, trying to predict the consequences.

Man standing next to a large old tree.

OSU researcher Rick Miller checks out an eastern Oregon juniper tree several hundred years old. Photo: Lynn Ketchum

Just as the baby boom in the United States can be traced to changes in the economy and post-World War II marriages, the spread of these young junipers has historical underpinnings.

It's not that trees more than 100 years old are dying particularly fast. The population shift is due to a rapid spread of young junipers, explains Rick Miller, an OSU range scientist. He's traced the beginnings of the juniper spread to the 1870s.

"About 100 years ago growing conditions were ideal and the area had been overgrazed by an influx of cattle, sheep and horses that came with homesteaders. Junipers were also cut for fence posts and other building materials," said Miller.

"So, what you see today are the larger, older trees in the fire-safe rimrock areas," he continued, "and the trees that began to quickly propagate during the 10-15 year intensive grazing period that began in the 1870s."

Miller said grazing affects juniper growth indirectly. Animals eat most of the vegetation between the trees so when there is a fire, there is less burnable material to carry the fire across the range from tree to tree.

This "natural fire suppression" allowed many more junipers to live than in the centuries before grazing, according to the scientist.

"Most of this we can deduce from grazing and fire records, but we are still looking at a relatively small time span in the 10,000-year history of the western juniper belt that runs from John Day down to northwestern Nevada," said Miller.

"Looking at the rings of core samples from 1,300-year-old junipers gives us more information," Miller said. "For instance, we can look at fire and precipitation cycles and see that big fires are usually preceded by two to three years of good growth climate."

Tony Svejcar, an ARS researcher at the station, says the difficult part of his and Miller's work is "coming up with a management plan for thousands of acres, based on our smaller plot experiments and observations."

Two of the management tools the researchers have identified are cutting junipers and prescribed burning of sections of rangeland.

"Management experiments do yield dramatic changes," Svejcar said. "An uncut range plot might yield only 100 pounds of forage, while the cut plot produces 1,000 pounds per acre.

"When junipers don't dominate the plot, there is less erosion and more plant and animal diversity," he added.

Mixed approach best for blight control

A mix of "good" bacteria and chemicals looks like the best bet to control fire blight, a disease that kills pear and apple trees in a single season.

OSU plant pathologist Ken Johnson said experiments with two kinds of commercially available bacterial strains showed each is about 60 percent effective as a biological control of fire blight.

Apples hanging on a branch.

Fire blight attacks apple trees like this one. Photo: Bob Rost

Johnson wants to do better. So he is studying mixes of beneficial bacterial strains and genetically modified bacteria under a competitive grant he and colleagues Virginia Stockwell and Joyce Loper won from the U.S. Department of Agriculture. He is also experimenting with combinations of biological and chemical control.

Johnson said he had about 60 percent effective control in tests with the commercially available biological control agents Blight Ban A506 and Blight Ban C9-1, both of which contain beneficial bacteria.

"Neither treatment is as good as (the antibiotic) streptomycin used to be, but the fire blight pathogen has become resistant to streptomycin," Johnson said.

The bacterial treatments work by crowding out the "bad" bacteria (the pathogens) on the fruit tree flowers.

"If we crowd out the pathogen, honeybees won't be able to spread the disease throughout the tree or to other trees," Johnson said. "By using biological controls, we can reduce the amount of chemicals needed and we can improve control."

In orchard tests, combinations of biological control agents and the antibiotics streptomycin or oxytetracycline gave nearly complete fire blight control.

Fire blight disease damaged several orchards last year near Hood River, Ore., and in Washington state.

Study assesses value of El Niño forecasts

If weather forecasters could predict El Niño events with perfect accuracy, farmers in the United States could save $323 million a year in crop losses associated with the unusual ocean warming that is El Niño.

But even if farmers used the current less-than-perfect El Niño forecasting system when planting their crops, they could save $250 million annually.

Those are among the findings of a research group that includes Richard Adams, a professor of agricultural and resource economics at Oregon State University.

Adams is a principal author of a research paper, titled "The Value of Improved ENSO prediction to U.S. Agriculture," that will appear in June in Climatic Change, an academic journal. ENSO stands for El Niño Southern Oscillation.

Although the term El Niño has become synonymous with a series of strong Pacific storms of the type that swamped Southern California this past winter, those storms are just one of El Niño's effects.

The name actually refers to ocean warming of designated areas off the Pacific coasts of Ecuador and Peru. If the 5-month average surface temperature in these tropical Pacific regions is warmer by 0.5 degrees C between October to December, then that is classified as an El Niño event.

But ENSO also refers to the opposite event: If the average surface temperature in the same area and time period is 0.5 degrees C colder, then the year is classified an El Viejo, or below-normal ocean temperature year.

Being able to predict whether an upcoming winter would bring El Niño or El Viejo conditions would allow farmers to plan crops that would better withstand the unusual climatic year.

Scientists already have improved their forecasting of such ocean warming or cooling events up to 18 months in advance through a system of temperature monitoring equipment established in the southern Pacific Ocean.

Farmers already are making use of this network. For example, strawberry farmers in California prepared for last winter's El Niño event by planting their crops on higher, well-drained fields in anticipation of lowland flooding.

Adams' study focuses on a 40-year period between 1947?1986. Nine of those were El Niño years, when the water temperature was warmer than average.

The water temperature was colder than average for 12 of those years. By studying crop yields for the nine most valuable crops in the United States, and putting them into a computer model, Adams and the other researchers were able to estimate both the crop yields and the economic effects of the changes in those yields.

Hops fight cancer in cellular studies

Can beer help you fight cancer?

OSU scientists aren't saying that. But they have done studies with mouse and human cells in which compounds in hops, cone-shaped flowers used to flavor and preserve beer, seemed to work against the disease. The researchers reported their findings recently at the annual meeting of the international Society of Toxicology.

The compounds under study are called flavonoids.

Man holding a hops flower.

A hop flower raised on one of OSU's experimental farms. Photo: Dennis Hinkamp

"We knew flavonoids from other plants had these types of effects so we decided to test hop flavonoids for anti-cancer activity," said Donald Buhler, an agricultural chemist with OSU's Agricultural Experiment Station.

"We treated human breast, colon and ovarian cells that were cancerous with concentrations (of flavonoids) that were not harmful to normal cells and found that some of the hop flavonoids were toxic to cancer cells," said Buhler.

The substance in the hop flavonoids most toxic to cancer cells is named xanthohumol.

The OSU research team conducted two related experiments. In one, some flavonoids in hops helped inhibit an enzyme, commonly called cytochrome P450, that can activate the cancer process.

In another experiment, some of the flavonoids helped enhance the impact of a class of enzymes, called quinone reductase, that can detoxify cancer-causing substances that have been activated.

"It's a little early in the game to start jumping to conclusions," said Buhler. "We're planning additional studies with mice that could provide more telling results."

The researcher said the hop flavonoids are in beer. The level depends partly on the brewing process used.

"I wouldn't encourage people to drink more," he said. "Obviously there's a down side to drinking. But these results are really interesting. If these things really prove to be beneficial it might be possible to find a way to get them to people in capsules or some other concentrated form."

Members of the OSU research team, besides Buhler, are: Max Deinzer, Rosita Rodriguez, Cristobal Miranda, Fred Stevens, Marilyn Henderson, Lalith Aponoso and Angela Sharps. The researchers are from OSU's departments of Agricultural Chemistry, Biochemistry and Biophysics, Chemistry, and from the university's College of Pharmacy.

Eastern Oregon study considers range's role in global warming

Questions about global warming keep rolling through our national psyche like tumbleweeds. Now scientists at the Eastern Oregon Agricultural Research Center at Burns, operated by Oregon State University and the U.S. Department of Agriculture's Agricultural Research Service, say some of the answers are out on the range.

Rangelands, including grasslands, cover about half of the earth's land and account for a third of all plant life. But we don't know how they fit into the global climate change puzzle, says Tony Svejcar, an ARS scientist at the center.

Man kneeling and looking at crop.

Researcher Tony Svejcar with plants in global warming study. Photo: Dennis Hinkamp

"The role of oceans and forests in the global carbon cycle has been studied, but rangelands have received relatively little attention," said Svejcar. "Scientists have been unable to account for a substantial amount of the earth's carbon. Rangelands (including grasslands) may hold the key."

You probably know the global warming scenario: Humans and other animals produce carbon dioxide, plant life consumes it, and the balance of this equation apparently is changing.

There seems to be a carbon dioxide increase in the atmosphere due to an arising world population that burns fossil fuels, and other factors. Researchers don't know exactly what this means for long-term climate change but many believe our atmosphere is warming.

There also are suggestions that the world's climate may change as a result of increasing CO2 whether there is significant warming or not. The timing of precipitation is one of the climate factors that could change.

About 35 miles west of Burns, Svejcar and other scientists are taking part in a national attempt to learn more about the rangeland-carbon dioxide relationship and about how precipitation timing affects plant life on rangelands.

Their experiments involve space-age instrumentation and sheds that look kind of like picnic pavilions.

A device called "the Bowen ratio/energy balance unit" looks sophisticated with its digital readout and solar power panels. But it makes a fairly simple, though precise, measurement.

"It measures the difference between the carbon dioxide content of the air at two different levels-one just above the plants and the other about three feet above the canopy (of rangeland plants)," explained ARS scientist Raymond Angell.

"It can detect concentration changes as small as one part per million," Angell said. "This can tell us whether CO2 is being drawn into the plant life or being released into the atmosphere. There are 11 more of these devices around western rangelands at ARS facilities."

Angell notes that this large-scale measurement is supplemented by small-scale, one-meter plastic chambers that can be placed over individual plants.

On the low-tech end are the five sheds that look like picnic shelters. They're open on the sides and fitted with sprinklers.

Svejcar explains that the five 20- by 40-meter sheds simulate different precipitation patterns. Each shed has three different rainfall environments, one with more rain in winter, one with more in spring and the third representing an average distribution based on rainfall records.

"As a control, we're tracking an uncovered plot just outside the shed," said Svejcar.

The experiment measures plant growth, distribution and diversity under these different rainfall conditions.

Svejcar explains that one theory about global climate change is that fluctuations are becoming more pronounced.

"The climate in the high desert has always been variable," he said. "This area has an annual average rainfall of 11.5 inches. But in 1993 we recorded a record high of 21.6, and the very next year recorded a record low of 5.6 inches.

"What we may see in the future is not necessarily a reduction in rainfall but altered rainfall patterns," Svejcar speculated. "Rainfall patterns have shifted in the past and no doubt will in the future."

OSU range scientist Rick Miller is leading the study of plant composition, such as increases and decreases in grasses and shrubs under various conditions. "We're also looking at plant physiology-for example, how different conditions affect photosynthesis," said Miller.

"Forests certainly receive the lion's share of public attention," said Svejcar, "but the arid lands may also be critical to the global climate picture. These experiments may help give us a better idea of how critical they are."

Yeast rips rot

Normally, there are a few hundred yeast cells on a pear. They can help naturally heal injuries and protect the fruit from rot.

A million yeast cells would do the job a lot better.

So goes the thinking of Oregon State University scientists working on natural, biological controls to thwart the rot that takes a $3 million toll on the pear industry each year in the Pacific Northwest.

"We're looking at an integrated control program for the rot, and yeasts could play a big part," said David Sugar, a plant pathologist at OSU's Southern Oregon Research and Extension Center.

"Most rots start at tiny injuries in the fruit during harvest and handling. If we can get beneficial yeast cells on the fruit before harvest and injury, they might protect the fruit."

Sugar said untreated pears have several hundred yeast cells per fruit. With yeast sprays, he and OSU graduate student Jesse Benbow have been able to boost that number to a million cells per fruit.

More good news: The cells survived at least three weeks in hot, summer heat-long enough to reduce incidences of rot.

Yeast sprays can't completely prevent rot. Sugar said producers will also have to use high-carbon dioxide storage of the pears and other techniques.

"Our research shows the combination of high carbon dioxide and low oxygen also keeps rot from developing," he said.