DANA — Farmers know that when the cold sets in, the worst companion is a calm still night.
Wind blows warmer air down into orchards, enough in most cases to spare fragile apple buds vulnerable to a spring frost or freeze. If Mother Nature won't cooperate, a man-made wind machine is the next best answer, a wind machine salesman told apple farmers this week.
Dave Harmening, of Cascade Wind Machine Service, demonstrated an Orchard-Rite wind machine on Monday at Wayne Pace's farm across from Dana Elementary School. He cranked up the motor and the 19½-foot blade on a 35-foot steel tower started rotating, slowly at first, then faster and faster. It sounded like a very big helicopter.
"We know that this area needs wind machines if you're going to have high quality, high quantity fruit year in and year out," Harmening said, as some of the growers nodded ever so slightly.
They might be nodding more vigorously as the weeks go on.
Like last year and 2007, the winter of 2013 is shaping up unseasonably warm, posing the threat of early budding of the apple trees that produce a $24 million crop in Henderson County. Farmers who were able to freeze-protect last year did well because they had a crop when fellow growers, here and up and down the East Coast, did not. The price of apples soared.
Based in Washington state, Harmening has seen wind machines eliminate or greatly reduce freeze damage to orchards there. He travels all over selling them.
"In Fort Myers (Fla.) we had a hundred machines on Pine Island that came through after Hurricane Charlie without damage," he said. He has sold them for palm tree nurseries, like the one on Pine Island, orange groves, apple orchards and vegetable fields. He checked wind machines by satellite Sunday night that had been working to save the orange crop from a blast of frigid air that reached southern California.
"The hardest part for farmers is to trust them," he said.
If the machine is wired to an auto-start system, a thermostat based on a reading in the orchard kicks on the motor. As the wind blows, the temperature in the orchard rises, and the wind machine will automatically shut off.
"Look at your critical temperature chart," he replied when a farmer asked where to set the thermostat. "You start 3-4 degrees above whatever your critical temperature is," Harmening said. "Your buds could be 4 degrees colder (than the air temperature) if it's calm and it's clear." Plus, "you can have markings and damage to the fruit above the kill temperature. If you're raising fruit like Red Delicious we have growers that are starting 6 degrees higher than critical."
The wind "mixes the warm in, moves the air across the buds and keeps it from supercooling," he said. "It keeps that air from stagnating and getting colder and colder."
A wind machine that covers 10-12 acres costs $30,000, including the cost of pouring a pad of seven yards of concrete and heavy-duty bolts. Most farmers finance the machines as a lease-purchase, spreading the cost over five years and bringing the investment down to $600 per acre.
"You're letting five crops pay for it instead of one," Harmening said.
Operating cost? Fourteen gallons an hour for diesel, 8 gallons an hour for propane. About 80 percent of the machines sold are propane powered.
Pace has erected three Orchard-Rite machines, enough to cover his 25-acre orchard.
Tony Hill, who is Pace's cousin and farms some of the same land, used an older wind machine during the April 2012 freeze that killed most of the county's apple crop.
"I feel certain there wouldn't have been any if I didn't have it running," Hill said. "I'm putting up three more right now. I wish I could afford new ones like Wayne did ... I'm a firm believer in them. I've had them for years."
He estimated that the wind machine paid for itself and then some.
"I would be willing to bet it made me $20,000 and that's net," he said.