By Seth Truscott, College of Agricultural, Human & Natural Resource Sciences
From the Skagit to the Palouse, observers with Washington State University are noticing that some agricultural crops are several weeks ahead of schedule—thanks to an unseasonably warm winter.
“It hasn’t been very winter-like so far,” said Nic Loyd, a meteorologist for AgWeatherNet based at the WSU Irrigated Agriculture Research and Extension Center in Prosser. AgWeatherNet operates 160 automated weather stations in Washington and Oregon. Loyd collects the weather data to help farmers make informed decisions.
“December was warmer than normal, January was warmer than normal,” Loyd said. The greatest anomalies are in the mountains, where there have been few chances for snow: “When it’s been wet, it’s been warm,” he said.
In December, AgWeatherNet measured temperatures in the Washington cities of Mount Vernon, Wenatchee, the Tri-Cities, Walla Walla, Moses Lake, Prosser and Moxee. Mean temperatures for the month averaged 3.6 degrees higher than historic averages. Temperatures in Prosser, the only location where results were available for January, averaged 1.3 degrees higher that month.
Out of the cold
In western Washington’s Skagit County, a warm snap in February jump-started fruit and flower crops. Meanwhile, in central Washington, tree fruit bud development is about 2½ weeks ahead of schedule, said Lee Kalcsits, assistant professor of tree fruit physiology at the WSU Tree Fruit Research and Extension Center in Wenatchee. Washington grape growers are also facing early budding and development of vines.
“Warmer temperatures and early budbreak increase the risk of frost damage for growers,” said Kalcsits. “It could be an issue if temperatures become cold again.”
“The big message for growers is, you can’t farm by the calendar,” said Stephen Guy, a WSU Extension agronomist in Pullman. “You’ve got to farm by the temperature.”
As Guy puts it, plants don’t care whether it’s winter or spring. Temperature, not day length, is what drives plant development.
In winter, plants go dormant and harden, developing an increased tolerance for cold.
“That reaches a bottom point and starts back up again,” he said. “We’re pretty much out of that now.”
Rising temperatures bring plants out of their winter hardness and get them ready to flower. That puts crops like tree fruits and grapes at risk of a spring frost.
“Plants are the most vulnerable to freezing when they flower,” Guy said. “We get freezing temperatures clear into June. The pollination process is very cold-sensitive.”
AgWeatherNet reports that above-normal temperatures and below-normal precipitation are expected for 2015, based on reports by the National Weather Service’s Climate Prediction Center.
Weather alerts and WSU Extension help
To help farmers with early crop development, AgWeatherNet offers email alerts for frosts and other adverse weather. It can also help growers schedule irrigation and use water more effectively.
“Hopefully, we can give them time enough to take action,” Loyd said. “There could be some cold days in early March, whether we like it or not.”
To sign up for AgWeatherNet alerts, start an account at http://www.weather.wsu.edu.
WSU Extension agents are available to answer questions about winter weather and agriculture. Learn more at http://cahnrs.wsu.edu/extension.
Nic Loyd, WSU AgWeatherNet meteorologist, 509-786-9357, firstname.lastname@example.org
Lee Kalcsits, WSU assistant professor of tree fruit physiology, 509-663-8181, email@example.com
Stephen Guy, WSU Extension agronomist, 509-335-5831, sguy@wsu