Abrupt rapid freeze damaged trees across Central Washington

By DAN WHEAT

Capital Press

Pacific Northwest cherry crops have grown larger over the past five years from increased plantings, but last November's freeze will keep the 2011 crop from setting a record.

The record crop was 20.5 million, 20-pound boxes in 2009, but this year's crop probably will be in the 12 million to 16 million-box range because of damage from the rapid freeze, said B.J. Thurlby, president of the Washington State Fruit Commission and Northwest Cherry Growers in Yakima.

"Growers are seeing some significant browning in tissue behind buds, which usually indicates no fruit," Thurlby said, adding the extent of damage won't be known until bloom in April and May.

"If a grower loses 10 percent of his buds at the start that's a scary deal," Thurlby said. "He still has spring frost and weather to get through."

Temperatures plunged from about 50 degrees to below zero within a week just before Thanksgiving throughout tree-fruit-growing regions of Central Washington.

It was 2 degrees below zero on Nov. 23 and 4 degrees below on Nov. 24 at the Washington State University Tree Fruit Research and Extension Center in Wenatchee. They were the first below zero readings in November at the center since recordings began there in the early 1930s.

Tim Smith, WSU tree fruit specialist, has said the damage was caused by the rapid drop from higher temperatures, which left trees no time to acclimate.

He expects damage to cherry trees and possibly other stone fruit trees like peaches, nectarines and apricots. Pears and apples are more freeze resistant. Young trees are more susceptible than old and tree trunks can be damaged more than buds because buds become winter hardy sooner than trunks, Smith has said.

So far damage appears greater in Benton City and other parts of southern central Washington than in Wenatchee, Thurlby said.

"I think everyone has a little bit of it," he said.

Denny Hayden, a grower near Pasco, said he sees quite a bit of discoloration in spurs behind green buds but that if spring comes on slowly there may be good recovery. Rapid warming would mean more damage, he said.

Cameron Lewis, an East Wenatchee grower, said he's put twigs in water and bloomed out the buds, showing mixed results of damage and no damage.

The Northwest produced 14.1 million boxes of cherries in 2010 in 89 days, which made for better sales and grower returns than the 20.5 million boxes within 45 days the year before.