Climate change may benefit Down East Maine’s cranberry growers

MACHIAS, Maine — Climate change could prove to be — pardon the expression — a “berry” good thing for Down East Maine’s small-but-expanding cranberry industry as growers in Massachusetts and New Jersey are seeing their cranberry harvests undermined by warming temperatures.

Just as low-bush wild blueberry production is enhanced when plants on blueberry barrens are periodically burned off, cranberry vines thrive when exposed to cold weather. During summer, too much heat and sun can impact yield by scalding berries.

“Cranberries need so many hours of a chilling environment,” said Charles Armstrong, the Maine Extension Service’s cranberry specialist. “Being exposed to cold weather affects flowering. Without it, yields go way down. The warming that’s affecting cranberry growers in Massachusetts and New Jersey could prove to be a good thing for growers in Maine and New Brunswick.”

Compared to wild blueberry production, the cultivation of cranberries in Maine is a cottage industry. Armstrong said there are only about 30 growers statewide, with most clustered in and around Washington County. Cranberry bogs in Maine range in size from one acre to six, and collectively, in 2011, there were just over 200 acres in production.

Armstrong said Maine growers are coming off a mediocre 2011 harvest. He estimates last year’s yield at 23,663 barrels, with each barrel representing 100 pounds of the tart berries. That’s down from 29,142 barrels in 2010 but up significantly from 18,000 barrels 10 years ago, an indicator of the expansion of the industry.

“The last harvest was sort of boom or bust, a tale-of-two-cities situation,” he said. “There were two growers around Augusta who had bumper crops, with yields of about 261 barrels per acre. Other growers saw their yields down, in some cases because of a lot of pruning being done after the 2010 harvest, which is similar to burning blueberry plants. It’s sort of a mechanical haircut for the vines, and the cuttings are used to seed new vines.”

Armstrong said the 2011 harvest also was affected by the Passamaquoddy nation’s decision to take 19 acres of bogs out of production in Down East Maine.

The U.S. Department of Agriculture estimates the 2011 cranberry harvest nationally to be 7.5 million barrels, which makes Maine’s 23,600 barrels nominal. Wisconsin’s harvest was estimated at 4.3 million barrels, followed by 2.1 million for Massachusetts and 540,000 for New Jersey.

Armstrong said prices paid for Maine’s 2011 harvest were “not stellar.” Like many agricultural endeavors, a “good year” financially, he said, means breaking even. Cranberries harvested “wet” in flooded bogs for commercial processing brought about 40 cents a pound, while dried berries, which have a longer shelf life, were bringing $1.75 to $2 a pound last fall. Armstrong estimates that wet harvest accounted for about 20,000 barrels, compared with 4,000 for the dry harvest.

Armstrong predicts cranberry yields in Maine will increase as growers to the south see temperatures continue to warm.

“Because of our location, we should see increases in production,” he said. “Due to climate change, there are some dire predictions for the rest of the country. New Jersey and Massachusetts growers are hugely afraid that it will be warm enough there that cranberries won’t meet their chilling requirement.”

The recent arrival of an Asian fruit fly doesn’t have cranberry producers as worried as blueberry producers. Armstrong said fewer of the pests have shown up in traps used to monitor cranberry bogs than have been seen in insect traps set in blueberry barrens.

“They’ve shown up in other regions, like Michigan and British Columbia, but it looks as if the skin on cranberries, compared to blueberries, is so tough that it repels these flys,” Armstrong said. “We’ll do more trapping this season to see what’s happening.”