Apples growing in the summer time at the Fairbanks Experiment Farm.
High tunnels for apple research erected at the Fairbanks Experiment Farm in 2007 have succumbed over the past two winters to heavy snow load.
"Research doesn't always produce positive results," said SNRAS Dean and AFES Director Carol Lewis. "We learned this type of extremely large hoop house is not sustainable through our winters."
The caved-in facilities, which have drawn the spotlight from local media, will be cleaned up by June 1. The work must go out for bid, as per university regulations. It was nearly impossible to keep the snow removed from the structures because they were so high. "Even a cherry picker could not reach them," Lewis explained.
The tunnels were originally a project of UAF Cooperative Extension Service. The lead researcher, forestry specialist Bob Wheeler, who died in 2009, had requested space at the farm to place the tunnels. Upon Wheeler's passing, CES asked SNRAS Professor Meriam Karlsson to oversee the project, assisted by CES's Kendra Calhoun, research technician.
This excerpt from a 2009 CES news release explains the project:
The apple varieties tested are those known to grow in colder climates. Their names won’t be recognizable to most:
Arctic Red, Carroll, Ukalskoje and Golden Uralian, among others. The varieties were grafted onto rootstock of the Ranetka crabapple, which is known for its ability to withstand cold winters.
The continuing project is evaluating trees grown inside and outside of the high tunnels.
Two weather stations and 10 micro-stations record environmental conditions hourly, including the soil and air temperatures inside and outside the tunnels, as well as soil moisture, wind speed and solar radiation.
According to Calhoun, Wheeler did not expect much fruit until three years into the
project. He was surprised when the trees fruited in their second year and delighted with the growth this year, she said.
Although the data for this year is not complete, Calhoun said it’s clear that trees inside
the tunnel are blossoming and fruiting more than two weeks earlier than the other trees.
“The tunnels, obviously, are helping,” she said.
The end walls of the greenhouses are erected in mid-October to help preserve the heat
inside the high tunnels. During winters, temperatures inside the greenhouse averaged 10-15 degrees higher than the outside temperatures, but soil temperatures were as much as 20 degrees colder inside, the result of the snow outside insulating the ground, she said.
Despite the colder soil temperatures, 80 percent of the trees grown inside the high
tunnels survived both winters. Sixty-eight percent of the outside trees survived the first winter.
After January 2009 temperatures dipped to nearly 50 below zero, only 45 percent of the
outside trees survived the second winter.
Apple trees that died the first year were replaced with new seedlings the following year,
except for the Asian pear, plum and cherry trees, of which none survived.
A variety of berries were planted inside and outside the tunnels, including red and black
currants, nagoonberry and honey berry. The berries outside the tunnels had a higher survival overall than those planted within, which was not too surprising, according to Calhoun.
The project is funded by a grant from the Western Sustainable Agriculture Research and Education Program.
Funding for the project expired two years ago but the apple trees have continued to grow and produce fruit. The covers will be removed and the apples allowed to grow outdoors.
Further reading:
Fruit Tree and Berry Crop Trial Program for Alaskan Native Rural Communities in Interior Alaska, UAF Cooperative Extension Service
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