Big fan saves fragile blooms at Sunbury area orchard
RESLER - With fruit trees bursting into bloom under the warm April sun, Ken Dries has hope he won't have to use another item he's recently planted in his fields.
The new wind machine towering over the fields at Dries Orchards Inc., is designed to prevent cold air, which can be detrimental to the fragile blooms of fruit trees, from settling in the valleys of the orchard.
One frost-bearing cold snap could freeze the tiny pink and white flowers on his trees, costing him tens of thousands of dollars in crop damage, he said.
The wind machine is designed to help the temperatures remain consistently above the 32 degree mark.
"If it's clear and no wind, and they're calling for dips in the low 30s, we'll be watching," said Dries.
When calm, cloudless nights occur, unbound warm air escapes upward into the sky. Cold air, which is heavier, slides down hillsides and pools in valleys. As a result, the temperatures in Dries' upper and lower orchards can be as much as 8 degrees apart.
The wind machine combats this pooling effect by circulating cold air out of the valley, mixing it with warmer air stagnating 30 feet higher.
The machine, which looks like a windmill, stands 35 feet above rows of 3-year-old peach and nectarine trees and 2-year-old apple trees. Its 25 foot blades run on a 10 cylinder propane-fueled motor. The fan rotates in a full horizontal circle and can provide wind for 12 acres.
Arriving in mid-March, a crane stood the stem of the wind machine onto a four-foot thick cement base. The blades and motor were then attached. The cost of the wind machine was approximately $33,000, and one 500 gallon tank of propane lasts three nights.
"If we save one crop, that pays for it," said Dries.
The wind machines are designed to last at least as long as the life of the trees below them, which can be more than 30 years.
This machine is the second of its type in Dries's arsenal. The first, purchased approximately 10 years ago, went unused for three years. During years four and five, frosts caused by nighttime temperature dips were staved off, resulting in no damage.
"It's definitely saved the crops for us," said Dries.
Previously, Dries used a number of other techniques in the fight against frost, such as the "Frost Dragon," which he describes as "a big fan and propane burner that you hook up to a trailer and drive around."
Because temperatures tend to dip after midnight, Dries and his employees would circle the fields with the "Frost Dragon" from 1 a.m. until sunrise. The heat effects would last for 12 minutes, allowing him to cover a 12 acre area.
Dries also uses an overhead irrigation spray system to prevent frost on his strawberries. With this type of system, heat is generated through the freezing process of water, warming blooms to prevent damage.
Previously, a large-scale overhead irrigation spray system was used on fruit trees, but Dries found this type of system to be too taxing with the amount of maintenance it required.
With the new turbine, once freezing weather is detected, he only needs to flip a switch for all-night temperature control.
"If they call for a cool frosty night, we will be out here," said Dries.
Even with this year's steady warm afternoons, Dries has already seen the effects of a sudden dip in temperatures: damage to his sweet cherry blossoms located beyond the effects of his new wind machine.
Fortunately, the damage has been minimal, and other later-blooming trees have been spared.
"The other crops look good so far," Dries said.
With three weeks to go until the unofficial frost all-clear May 20, Dries is prepared to spring his wind machine into action.