In the Northwest, blueberry buds have started to plump up, but cold snaps could kill them. To prevent losses to their crops, blueberry farmers are waging war on the frost. Their battles involve intensive crop monitoring and all night vigils.
At Olsen Brothers Ranches outside of Prosser, Washington, there is a retro-looking frost alarm that sings to wake workers when frost bites at night.
A skeleton crew rattles out with the first alarms to drive around the pitch-black fields.
“Cold spots move around on us,” says Keith Oliver, who oversees hundreds of acres of valuable fruit at the farm. And 800 pickers.
“We have hundreds of thermometers scattered throughout the farms,” Oliver notes. “And people are driving around at night looking at those things after the frost alarms go off. And we have to just keep watching and jumping around and trying to stay one step ahead of it.”
“With our organic blueberries right now, we spend the most money per acre growing them and we can make the most money per acre selling them,” he says. “If things go right.”
Timing the battle
Sometimes the frost alarms go off as early as 9 p.m. That means already-worked and tired crews have to head back to the farm for an all-night battle.
On a really bad, cold night workers find the coldest spots, then scramble to start irrigation sprinklers. Then they start waking up even more workers -- phone-tree style. Soon giant wind machines will sputter to life and workers will light up hundreds of propane heaters.
All that usually saves some blueberry buds. But some years all this work doesn’t pay in the end -- if one night is too cold for too long.
Timing the battle cry for the cold war each night is key. If you wake workers up and turn everything on too soon, Oliver says it’s like “burning money.” Thousands of dollars per hour.
If you start the fight too late, you risk major crop-drag.
New science and better tech
Washington State University scientists are amassing data by freezing cut branches from the fields every week in a lab. Then cutting open each bud and seeing what survives different temps. Other Northwest crops already have these precise cold-hardy models.
But the Northwest’s blueberry boom has outrun science. WSU scientist Gwen Hoheisel says it will take 10 more years of data to make a useful real-time model for farmers.
If Oliver and other Washington farmers win the frost war, they’ll likely harvest more than $100 million worth of blueberries this summer.
Source: NWNews