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Withering weather

Warm temperatures threaten many Washington County crops, but grape growers are hopeful

Photo Credit: COURTESY PHOTO - Jim Witte spent last weekend pruning his vineyard, trying to finish the task before the buds break out weeks ahead of schedule. While many Washington County residents are happy to sneak outside for a little lunch-break sunshine or play weekend warrior without getting doused, the warm weather has blueberry farmers shaking in their boots.

They may be the hardest hit among many local farmers who are keeping a close eye on their crops due to the Portland area’s warmest winter ever recorded. February alone was an average 5.5 degrees warmer than usual.

Plants have awoken from their winter sleep about three weeks ahead of schedule, according to Oregon State University (OSU) scientists. For some crops, that could mean a longer growing season with larger fruit. For others it could mean devastation.

“The potential for damage is humongous,” said Ross Penhallegon, an OSU Extension horticulture agent, as frost is not unusual in March and April. “According to the plants, winter is over, but Mother Nature can mess that up for us.”

Other than farmers, most people don’t spend a lot of time pondering the complicated network of sunshine, rainfall, pest species, soil condition and other factors that produce the food we eat and the drinks we sip. But there’s nothing like rising temperatures and thirsty rain gauges to remind us that Washington County crops depend on a precariously balanced ecosystem. Change one factor and everything shifts.

Bullseye on blueberries

Legacy, one of the earliest-ripening blueberry varieties, has had blooms for three weeks, according to Wei Yang, an OSU Extension agent specializing in commercial blueberry production.

“You just don’t usually see blueberry blooms in mid-February,” Yang said.

One of the main concerns for blueberry farmers is the potential for frost. Once the plants wake up from the winter and come out of dormancy, they can no longer tolerate low temperatures.

Tight blossoms can tolerate cold to around 24 degrees Fahrenheit, but open blossoms can only tolerate weather that drops to 27 or 28 degrees before they’re killed, according to Yang.

Chances for frost in March and April are still high.

Farmers with early blossoms are starting to think about pollination problems as well. Certain kinds of bees don’t usually come out until late March but the flowers are ready for pollination now. In addition, there aren’t enough wild bees to pollinate Oregon’s commercial crops, Yang said, so farmers usually rent hives to help the process. But this is the time of year almond growers in southern California reserve the commercial beehives, so they’re not available right now for Oregon farmers.

In addition, the mild winter will likely spark a population boom of the Spotted Wing Drosophila, Yang said, a fruit fly that lays eggs in blueberries right before they’re ready to be picked. Consumers don’t want to eat blueberries with larva in them, Yang said. A regular cold winter would normally kill much of Drosophila population. Photo Credit: NEWS-TIMES PHOTO: DOUG BURKHARDT - Blooms on fruit trees are popping out all over town nearly a month earlier than usual.

These are big concerns in Oregon, where blueberries are the most profitable berry, according to 2012 data — the most recent available — gathered by the Oregon Department of Agriculture. With 2,000 acres, Washington County is second only to Marion County in blueberry production.

But more than a quarter of those acres are new, added since 2010, and aren’t yet set up with special frost-deterring irrigation systems like more established fields, Yang said.

Worries widespread

Blueberry farmers aren’t the only ones worrying. Orchardists could run into significant problems, said Penhallegon.

Penhallegon has already noticed blooms on prune and peach trees.

“Most crops are three weeks early, which gives us three more weeks to worry” about frost.

Galen Williams, who operates Bull Run Cider in Forest Grove with an accompanying nursery, said he and business partner Peter Mulligan had to hold a large portion of their tree orders this year. The pair grows, grafts and ships varieties of apple and pear trees ideal for making ciders all over the country.

Since trees have to be transplanted while they are dormant, Williams had to rush to fill orders and ran out of time for some. “It’s too warm to ship now,” Williams said. “The roots have been growing for a while.”

Williams isn’t too worried about his cider apple and pear orchard, though. “A lot of cider varieties bloom later, so hopefully we won’t hit any frost issues. I don’t think there’s a huge risk unless it gets really cold near the end of March.”

Peaches, apples and pears are among Helen Van Dyke’s long list of crops on her Hillsboro farm, where she’s used a variety of techniques to fend off frost — everything from sprinklers to burning sawdust in five-gallon buckets in her orchard.

Van Dyke has already noticed Brown Marmorated Stink Bugs lurking around her farm, another pest usually killed by a colder winter. The bug can cause widespread damage to orchards. “They’re around and I think they’re going to be a problem,” she said.

In her 60 years farming, Van Dyke has only seen trees bloom three to four weeks ahead of schedule a few times. “If it doesn’t freeze hard, everything might just be early.”

She remembers one year, they picked peaches nearly a month ahead of schedule, which didn’t pose many problems except that they weren’t prepared for harvesting so early.

Nicole Anderson, who specializes in commercial field crops for OSU Extension in Washington County, estimates wheat, clover and grass are about a month ahead of schedule and “could reach maturity early if it remains relatively dry.”

A season that continues to be dry could mean a need for increased irrigation — a potential problem for all crops in the region.

Clover, wheat and grass are often grown as dry-land crops without irrigation, but that depends on wet, cool springs and winters providing moisture during the early growing season. An early dry season could ruin that.Photo Credit: NEWS-TIMES PHOTO: DOUG BURKHARDT - While blooming trees are bringing beauty to the county in whats usually the doldrums of winter, the potential for freezing blossoms could be detrimental to this years fruit crops.

Grass seed, the county’s largest crop, Anderson said, could be affected by stem rust, a fungal disease that thrives in hot, dry conditions. The mild winter may have also helped out cereal leaf beetle populations, which consume wheat and oats.

“The best thing would be if it were to cool off for the next three weeks,” said Penhallegon. “But it doesn’t look like that’s going to happen.”

A few are lucky

Some farmers don’t have to worry at all. Hazelnuts, for example, are pollinated by wind and pollination has already finished this year. Hazelnut experts aren’t expecting trouble.

And some grape growers are even excited about the weather because long warm, dry seasons are conducive to a bumper crop of grapes.

That’s what happened last year, when an extended dry, warm season proved bountiful for Willamette Valley vineyards.

An early bud break combined with a spring frost could cause tissue damage, said Patty Skinkis, an OSU viticulture specialist, but without a hard frost it could get the season going earlier.

“Everyone is racing to get their pruning done before the bud break,” said Holly Witte, who operates Cornelius’ A Blooming Hill Vineyard & Winery with her husband, Jim. “It’s coming early this year.”

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