PARMA, Idaho — Researchers are seeing signs that a four-day stretch of record low temperatures in November caused damage to the state’s fruit crop.
Researchers at the University of Idaho’s Parma experiment station have seen extensive damage in some buds forced to break early in the laboratory.
“There is a definite injury to the bud structure itself,” said Mike Kiester, a research assistant with the station’s pomology program. “You’re going to see some damage this year.”
“Normally, you’re going to have a nice, beautiful green bud structure all the way through when you dice it,” Kiester said. “This year, there’s just a brown tint in there that’s off.”
Some fruit likely sustained severe damage, though the damage varies by location and fruit type, said Parma researcher Essie Fallahi, who heads the university’s pomology program.
“What the percentage of the damage is is really hard to say at this point,” Fallahi said. “We are definitely going to have a crop but how much of a crop, we don’t know yet.”
He said the extent of the damage won’t be known until May or June.
Apples look OK, but peaches and cherries are a different story, Kiester said.
“We’re not worried as much about them,” he said of apples, “but peaches and cherries definitely have some problems.”
Some table and wine grapes in the Parma station’s fruit orchard also sustained significant damage, said research assistant Tom Elias, president of the Snake River Table Grape Association.
Chad Henggeler, field manager for Henggeler Packing Co. in Fruitland, said the company is highly concerned about its cherries but its apples, peaches and plums look OK.
Henggeler is also concerned about the impact the November cold had on the company’s 30,000 1-year-old apple rootstock.
“Some varieties look better than others but we may have to prune them back significantly and regrow last year’s growth,” he said
Several daily low temperature records were set in mid-November across the Treasure Valley in Southwestern Idaho, where the majority of the state’s fruit crop is grown.
The mercury dropped to minus 5 at Parma and the low hovered near zero for four days.
The problem for fruit in the region was caused by the suddenness of the temperature drop, before fruit trees had a chance to build cold hardiness and go into dormancy, Fallahi said.
The temperatures were “way too cold because the trees were not acclimated; they were not in dormancy,” he said.
Most fruit trees require a certain number of hours between 32 and 45 degrees to go into proper dormancy, Fallahi said, but the region didn’t come close to meeting those needs last November.
“We were working out in shirt sleeves and then ... whoosh, the temperature just went down,” Elias said.
Henggeler said fruit growers in the area can’t remember a similar year when temperatures dropped so quickly so early.
“It’s something that long-time fruit growers around here can’t ever remember seeing,” he said. “We’re kind of in unchartered territory.”