Tunnels the key for success of strawberries in winter

Sunday, March 15, 2009 3:00 AM  |  Printer friendly version | E-mail to a friend | By Emily Ford

eford@salisburypost.com

How would you like to bite into a fresh Patterson Farm strawberry on Christmas Eve?

Or dip one into chocolate on Valentine's Day?

Local strawberries, typically only a springtime treat, could show up in grocery stores next winter if Patterson Farm and N.C. State University win a grant to put high tunnels on the Rowan County farm.

High tunnels, all the rage in Europe, could extend Rowan County's strawberry season from eight weeks to about six months.

"Tunnels could equalize the playing field," said Doug Patterson, who farms with brother Randall and competes against much longer growing seasons in California and Florida.

For three years, experimental high tunnels at Piedmont Research Station near Salisbury have worked better than expected, nearly tripling the number of berries harvested from one plant, operations manager Andy Myers said. Myers gives the fruit away to groups that feed the hungry.

Now, scientists want to put the tunnels into real production and see what consumers will pay for locally grown, premium berries in the dead of winter.

They chose Patterson Farm.

"We got a fantastic partner," said Dr. Jeremy Pattison, N.C. State's new strawberry breeder and geneticist at the N.C. Research Campus in Kannapolis. "They have the marketing savvy and production savvy. They can prove its utility."

The team will learn on May 29 if it has won a grant from the N.C. Tobacco Trust Fund to cover one acre of Patterson Farm with high tunnels. The 150-feet-long, greenhouse-like structures with rounded tops covered with polyethylene plastic cost about $40,000 per acre.

Patterson Farm will determine if it's cost effective for North Carolina farmers to invest in such expensive technology.

Although Patterson Farm is known for pick-your-own strawberries, their tunnel-grown berries would be carefully monitored and picked only by employees.

"It's definitely going to be more labor intensive," Doug Patterson said.

While growers can leave strawberry fields alone for weeks at a time, they must tend to tunnels daily, raising and lowering huge flaps that adjust the temperature and moisture inside.

"After we agreed to do it, we looked at each other and said, what have we gotten ourselves into?" Patterson said.

But Pattison believes tunnels are worth the extra work.

They help berries resist disease and keep rain off the fruit, which can rot if it gets wet.

On a 40-degree day, a closed tunnel can reach 70 degrees with just the heat of the sun. Tunnels at the Research Station have protected blossoms and berries in single-digit temperatures.

"This can be a winner," Pattison said. "This has the potential."

Dr. Jim Ballington and Dr. Barclay Poling, small fruit specialists for N.C. State, started the tunnel project with Myers and Joanne Mowery at the Piedmont Research Station.

"We've had good successes and good failures," Myers said. "Sometimes you learn more from the failures."

This month's unusual snowfall caused one of the failures.

The team had seven or eight ripe berries on each plant when forecasters called for six inches of heavy snow.

Fearing the tunnels would collapse under the weight, Myers reluctantly pulled off the plastic, exposing the fruit to the elements.

Researchers hoped the snow and an additional layer of ice from an irrigation system would insulate the plants. But when the temperature fell to 11 degrees, most of the fruit and flowers froze.

"Andy did the right thing. It was a setback, but better it happens to us than growers," Pattison said. "We already have some good ideas to try for next year."

They should have new fruit by early April.

"This was some pretty extreme weather," Pattison said. "I'm actually happy that we have this in the data set."

Ultimately, the goal is to put tunnel-grown strawberries on grocery store shelves. Pattison will meet with high-end grocers to discuss what they would pay for the fruit, considering the popular local food movement.

A grower in South Carolina has used tunnels for five years. He earned $18 per gallon for tunnel-grown strawberries last Christmas, compared to about $10 per gallon for field-grown berries, Myers said.

"Something's working or he still wouldn't be doing it," Pattison said.

Despite setbacks like snow in March, Pattison said he's optimistic about the future of strawberries in North Carolina.

"There are a lot of challenges out there," he said. "But my true passion is to provide rubber-meets-the-road solutions to these guys to keep them competitive and sustainable, and keep them on the farms for generations to come."