WYOMING — With unseasonably cold temperatures over the past week, farmers have had to take unusual measures to ensure their crops’ survival.
“We were most worried about our peaches but we’re pretty optimistic that most of them will make it through,” said Mike Fennemore, a fourth-generation farmer at Fifer Orchards.
The first scare came last Wednesday morning when the temperature dipped into the mid-20s and frost began to form on the peach trees.
“Most of the time they will survive through a frost or two but we didn’t want to take any chances,” Mr. Fennemore said.
The helicopters over Fifer Orchards raised the ground temperature by 3 degrees by taking advantage of a rare temperature inversion — a warm layer of air above the cold air closest to the ground. The helicopter propellers push down the warm air, lessening the extent of frost damage. (Submitted Photo/Bobby Fifer)
So the heads of Fifer Orchards in Wyoming gathered and decided they needed to employ frost control.
One method is using a helicopter to stir up still air and to push warm air down to the trees.
Stirring up the air is important because still air is much more likely to allow for frost than wind, but generating warm air is a lot less reliable.
Generating warm air relies on the formation of a temperature inversion layer. Typically, air temperature decreases as elevation increases but in the case of temperature inversion, warmer air hangs above the cold air.
The helicopter propellers are able to push down the warm air from the inversion layer raising the ground temperature by about 3 degrees. It may seem like a small amount, but 3 degrees can be the difference between a healthy tree and a damaged one.
“The colder it is, the less acres you can do with one ship,” said Bobby Fifer, who deployed two helicopters on Wednesday. “It takes as long as it takes for the outside temperature to get safely back above 28 so we started frost control when the temp hit 28.”
He estimated that the two helicopters were able to raise the temperature about 3 degrees on a total of 100 acres of trees.
“It doesn’t always work,” Mr. Fifer said. “ We really can only pray and try to control what we can.”
Mr. Fennemore said the helicopters were on standby over the weekend too as the weather forecast for Saturday night into Sunday morning projected temperatures to dip into the mid-20s again.
“We really dodged a bullet Sunday morning,” Mr. Fennemore said. “The lowest temperature we recorded was 31 degrees and the wind was blowing between 10 and 12 miles per hour so we didn’t get the frost we had been worried about.”
Since frost usually isn’t a problem this late in the season, and if frost control had been needed over the weekend, it only would be the fourth time it’s been used in the past 22 years.
Before Wednesday, the last time helicopter frost control was used was in 2004 or 2005.
Dealing with frost this season came as somewhat of a surprise not just because of the unseasonably cold temperatures but also because the peach trees started to bloom in mid-March — two full weeks before they usually do. By the time the frost hit, the trees already were in post-bloom, the period when the petals begin to fall off.
Despite Wednesday’s frost and the weekend scare, Mr. Fennemore expects to have a full harvest of peaches this summer and said the other crops grown at the orchard were unfazed by the cold, so regular quality and quantities are expected.
But some downstate orchards don’t expect to be as fortunate as Fifer. Bennett Orchards of Frankford and T.S. Smith and Sons Farm of Bridgeville experienced lows of around 23 degrees last week, according to WBOC meteorology.
Charlie Smith, co-owner of T.S. Smith and Sons said the frost most likely caused some damage to its 60 acres of peaches but the extent can’t be determined until temperatures warm up.
“We had the frost last week and we’ve had colder than usual temperatures almost every night since,” he said. “We may know how we fared by the end of the week so we’ll have to wait it out, but now it’s too early to say what kind of damage we’re looking at.”
Peaches that were severely damaged by the frost will remain tiny, turn black and fall off the trees in the coming days and weeks. Once farmers see the number of peaches that have fallen, a determination of this year’s yield can be made.
Last week, Fifer Orchards deployed two helicopters over its 100 acres of peach trees to prevent frost damage. (Submitted Photo/Bobby Fifer)