After a late frost last year killed three-quarters of Knight Orchards’ apple crop, brothers Jeremy and Joshua Knight were willing to invest some money to save some of the crop if it happens again.
The Knights bought a new 30-foot-tall wind machine to circulate air on cold spring nights and protect vulnerable apple buds and fragile blossoms from frost in their town of Ballston orchards.
The wind machine works by pulling warmer air, which rises on a chilly night, down toward the ground, hopefully boosting the temperature of the lower air enough to prevent frost in the 10- to 15-acre range of a machine. It runs on gasoline or diesel and has two large blades.
“Come bloom time, if we start to go below 32 degrees when we’re in bloom, we’ll start it up,” Jeremy Knight said of the machine.
Last year, warm days in late March and early April spurred the apple trees to bud about a month earlier than usual, and then freezing temperatures for four nights in a row wiped many of them out.
In the Capital Region, the only apple orchards with the machines are Knight and DeVoe’s Rainbow Apple Orchards of Halfmoon, Knight said. Orchards in the Hudson Valley and the Champlain Valley also have them.
But more farmers may invest the money soon, said Larry DeVoe, whose family has used the machines for more than 50 years.
“After last year, there’ll be a lot of them.”
A change in weather is tough on farmers, who can lose thousands of dollars worth of fruit in a couple of cold nights.
However, there are limitations on the machines.
Knight’s one machine will save only some of the apple crop if there’s a repeat of last year, since the family has 75 acres of apple orchards. And with one operational machine last year, DeVoe’s still lost 90 percent of its apple crop to frost.
There are some cases where a wind machine can’t combat the cold.
“If you have a real hard freeze where it goes into the low 20s, it isn’t really going to help you,” Knight said. The farmers can light brush fires around the orchards to create more warm air for the giant fans to circulate.
Or they can hire a helicopter to circulate the air, if they have an extra $2,000 to spend per hour.
“Usually it’s just been, ‘keep our fingers crossed,’ ” Knight said. “We’ve decided to be a little bit more active now.”
Paying for themselves
The machines can quickly pay for themselves if they save several acres of apple blossoms from frost, said Knight, who figures he could recoup the roughly $30,000 he paid for his machine in one frosty night.
Wind machines are old hat now for DeVoe’s. Larry DeVoe recalls his father, Merritt, purchasing the first one in 1959 or 1960, after the family heard the machines were used with success in California and Florida citrus crops.
DeVoe’s was the first apple orchard in the Northeast to have a wind machine, Larry DeVoe said.
It has two machines now, though one of them broke down at a critical moment last year, the second night that they had to run it.
“Those old motors, they just can’t take the damn ethanol,” DeVoe said. His son, Craig, has converted that wind machine to run on propane this year.
“The wind machines work real well over the years,” Larry DeVoe said. “Most of the time, you can get a crop through.”
They usually raise the temperature on the ground by 3 to 4 degrees, and sometimes just 1 degree.
“There’s times when 1 degree is the difference between a crop and no crop.”
Apple trees are susceptible to frost from the time a cluster of buds forms through full blossom, DeVoe said.
“You can get damage as soon as there’s pink showing.”