Friday, March 29, 2013/lk
The recent up-and-down weather patterns in Hood River valley yet will not pose any significant impact to developing orchard fruit.
“It was a fairly mild February and things are moving along pretty good,” said horticulturist Steve Castagnoli. “The buds are primed and ready.”
Some freezing temperatures are a minor threat to the buds, but the greater concern for growers is wind combined with cold, he said.
“We had some periods of warm days (this month) and that really got things moving and then last week the cooler weather kind of stopped everything, but it’s not really out of the ordinary,” said Castagnoli, who is with Oregon State University Extension Service in Hood River.
“Our weather in the spring is so variable — it’s part of the mix,” Castagnoli said. “I think at this point we are on track for kind of a normal crop.”
The pear and apple buds “are at a stage where they can kind of sit without any significant harm,” he said. “From here until after bloom it’s more a case of the fruit development, the cells expanding or not actively dividing.
“There are a lot of other things that go into forming the bloom and fruit set, but none of that is being affected by the weather at this time.”
He said the buds are still “relatively hardy,” and that weather forecasts give him optimism.
“We haven’t seen any forecasts for the kind of conditions that would be concerning,” he said.
He cautioned that frost damage and protection are ac concern every year for growers.
“Of course, in the spring you never know what you will get,” he said.
Despite mid-March snowfall in the upper valley, Castagnoli said he is not aware of any active frost protection measures having been taken.
Temperatures dipped as low as 24 in Parkdale in early and mid-March, but in recent weeks the lowest temperatures at the Hood River Experiment Station were 28 degrees on March 9 and 30 degrees on morning of March 19.
Castagnoli said Parkdale is typically a week or two behind the lower valley. As buds have become more developed, thus open to the elements, the more susceptible they become, he explained.
Thus, the slightly delayed upper valley buds “probably have a few degrees more of a buffer than down in the lower valley,” he said.
A “worst-case scenario” would be a cold front that moved in with sustained temperatures of low 20s, according to Castagnoli.
“Because if you have wind and cold temperatures the growers can’t do anything about protecting them,” he said.
“Growers depend on inversion conditions with warmer air that they can mix with their fans down where the buds are.
“If the wind is moving it will blow the warm air out,” he said.