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Warm winter has fruit growers poised for action

The Rogue Valley's balmy mid-February days have set local peach and pear orchards on course for the earliest bloom on record.

Persistent spring-like temperatures in the middle of winter have triggered budding, leafing and blossoms on plants and trees, which is sure to keep commercial pear and peach growers fending off frost for the next two months.

Oregon State University horticulturist Rick Hilton, who works at the Southern Oregon Research and Extension Center on Hanley Road, said the average date for Bartlett pears to reach full bloom during the past 25 years has been April 6. The earliest date of full bloom occurred March 23, 1992, and the latest was April 21, 2011.

"Right now, depending on how you're calculating, we're two weeks early as of last week," Hilton said. "By the end of this week, we may be three weeks ahead; two weeks is a lot, actually."

Peaches mature earlier than pears, putting that crop at greater risk.

"This is the earliest we've ever protected,"  said veteran orchardist Ron Meyer, who grows 100 acres of pears and eight acres of peaches, along with a handful of apricots. "Sunday night, we turned on the fans for the peaches and put a few heaters around the apricots. The apricots can stand 27 degrees, and peaches should stand 24 (degrees), but that's pretty cold. We held ours to 27 (degrees)."

Pears are at an early enough stage, he said, that frost protection hasn't been necessary yet. But that could change very soon with local lows expected to hover in the 20s for several nights starting Saturday.

"Normally, our worst freezes come about the last two weeks of April," Meyer said. "But we'll be quite vulnerable all the way through April this year. It's much better to have it cold now than two weeks from now. In 1972, we had our worst frost ever on March 10, so this is a little scary. Pears are pretty tough, but at that tender stage when petals are falling, peaches have to be held at 29 degrees, and then for only half an hour. When pears are at that tender stage, you have to hold 32 degrees."

Hilton said a longer frost protection period means higher costs for growers.

"Frost control is very expensive," Hilton said. "We're not generally using smudge pots anymore, and diesel is a little cheaper this year, but it's still expensive."

Wind machines, which push warmer air to the ground and displace colder air, are the standard frost-control weapon.

"Growers are fairly adept at frost control, but when there is earlier bloom, you have the potential for more nights of frost control. People living near an orchard better get used to wind machines coming on at 4 or 5 in the morning."

Backyard fruit trees owners won't find traditional frost-protection methods practical, but there are affordable alternatives.

"I've talked to people who used old-fashion Christmas lights that give off heat," he said. "If people have one or two peach trees in the backyard, a few strings of Christmas lights might get them through."

City dwellers with backyard fruit trees have another advantage, Hilton said.

"They're generally warmer in an urban setting, where the trees are nearer to a house than in the countryside," he said. "The coldest orchards are usually 4 or 5 degrees colder than the readings at the airport."

Trees are more susceptible to disease during prolonged cold, as well.

Pseudomonas, commonly called blossom blast, is more prevalent when frost damages a tree, allowing bacteria living on the surface to enter the tree.

Unlike most people, Meyer is a big fan of the fog. "When we have fog in the lower valley, the air above it is warmer," he said. "It helps us stay cooler. We just don't have enough of those days."

With few historical parallels, Meyer isn't sure what to expect over the next two months.

"This is extraordinary," he said. "What happens after this? Who knows? But we'll be prepared for the worst."

Reach reporter Greg Stiles at 541-776-4463 or business@mailtribune.com. Follow him on Twitter at www.twitter.com/GregMTBusiness, on Facebook at https://www.facebook.com/greg.stiles.31, and read his blog at www.mailtribune.com/Economic Edge.