Up to 20% damage in almond orchards

A cold snap in the heart of California’s agriculture industry could be devastating to the almond crop and ultimately lead to higher prices. It follows three-straight nights of bitter-cold temperatures this week in the San Joaquin Valley — the hub of almond production — where temperatures sank to the low-20s overnight starting Tuesday. Almonds are in full bloom and vulnerable to frost damage that could wipe out future nuts on the trees. The weather forecast says more freezing temperatures could come this weekend.

The very cold air mass from western Canada brought the most frigid temperatures so far this winter and the coldest in years for some locations, the San Francisco/Monterey National Weather Service office said. The mercury dipped into the 20s and 30s in many areas and into single digits in some mountain locations before dawn. San Francisco International Airport was 36 (2.2 Celsius), breaking the record of 37 (2.7 Celsius) set on the date in 2011. Downtown Los Angeles was in the low 40s.

“I think it’s going to be significant, but we’re not going to know the extent of damage for some time,” said Bill Dietrich, who farms almonds in the Central Valley. “We’re at full bloom, which is not the most sensitive stage but it is a sensitive stage.”

Joe Del Bosque, owner of Del Bosque Farms on the west side of the San Joaquin Valley, said he’s concerned that there’s been damage to his cherry trees and his asparagus, but even more so to his almond crop. “They’re almost in full bloom so the whole crop is exposed and we’re pretty concerned,” Del Bosque said. He said temperatures dipped as low as 29 degrees (-1.6 Celsius) off and on for two hours at his 2,000-acre farm overnight. Damage won’t be apparent to any of his crop for at least a day or two, he said.

Another processor stated: “Packers have been out looking at orchards. It is really too early to make a good decision, but 20% to 25% damage seem to be the most popular numbers. Areas most effected seem to be Madera area and east of Modesto and Turlock. Actually, the whole growing region is effected to one degree or another. As I said, it is really too early to even make a good guess, but we need something to talk about. Regarding % of damage, the % of what? Packers are off the market waiting for more information. It will take a several day to really see the effects of this freeze. And, freeze risk really goes to about 15 April.”

Like most farmers,Joe Del Bosque is irrigating his orchards because water around the crops helps moderate temperatures. Almond orchards throughout the area were wearing icicles early Tuesday morning, as growers turned on their sprinklers to temper the cold weather’s impact on the blooms and young nuts. Sprinklers are the main weapon against damaging frost in almonds, according to UC Cooperative Extension Farm Adviser Luke Milliron. Although it varies with the kind of irrigation system in place, in-ground oscillating sprinklers can raise air temperatures in an orchard 3 to 4 degrees as the ice forms. Once the ice coats the flowers and nutlets, it prevents their temperature from dropping below 32 degrees, which is an unsafe level. Damage varies with the stage of the bloom. The pink buds are a bit hardier as they have a lot of sugar, which serves like an antifreeze, Milliron said. The young nuts are more susceptible to damage.

Jared Enos, a ranch manager for Carriere Farms in Glenn County, said the buds are safe to about 27 degrees and the blooms to about 28 degrees. But when the young nuts are formed, then can be damaged by temperatures of 31 to 32 degrees Interestingly the weather service website shows the “banana belt” in the foothills, with lows in Cohasset, Paradise and east Oroville all above freezing. Enos said the fight against the freeze begins well before the temperatures dip. The ground is soaked, as wet soil holds more heat from the sun. Then several hours before temperatures hit freezing, the pumps are turned on. Enos said Carriere turns them on at 37 degrees. That was about midnight to 1 a.m. Tuesday. Some ranches have temperature alarms, but Enos and one of his workers spent Sunday night and Monday night sleeping in one-hour increments and checking to see if it was cold enough to start the sprinklers.

The sprinklers run until the sun melts the ice off the trees. Some larger operations can’t pump enough water to protect their whole orchards, and hire helicopters to push warmer air from above — that banana belt elevation — down into the trees. Enos said he’d heard one operation had hired 18 helicopters for Tuesday morning.

If the crop is damaged, there could be a reduced supply available on the market and that could mean higher prices for consumers and food manufacturers. On Tuesday, the Blue Diamond Growers cooperative of more than 3,000 California almond growers warned that “all almond varieties are at significant risk of loss when overnight temperatures reach 28 degrees and below.”

The Blue Diamond Growers Coop President and CEO Mark Jansen praised President Trump’s “Tax Cut and Jobs Act” for providing tax relief for the 3,000 Blue Diamond family farms that do not have the clout to lobby government, like big agricultural companies.

Officials said there also is chance of damage to other crops, including deciduous tree fruit such as peaches, plums and nectarines as well as some citrus. Regardless, they said the extent of any damage may not be fully known for weeks or months since blossom damage to trees typically takes time to show up.

“Most likely there’s going to be some damage from the current weather situation we’re going through,” said Fresno County Farm Bureau CEO Ryan Jacobsen. “It’s just unknown how extensive it’s going to be.” Low temperatures were recorded as far north as Chico and down near Bakersfield in the state’s Cewntral Valley. Some almond growers took precautions by using wind machines or sprinklers to protect the blooms from frost and freezing.

The weather service recorded temperatures as low as 23 degrees Tuesday in some key growing counties and 25 degrees on Wednesday; upper-20s were common Thursday.

However, Friday morning brought some relief with cloud cover helping to keep temperatures out of the danger zone. However, the National Weather Service said a freeze watch remained in effect from Friday night through Saturday morning in parts of the Central Valley. “Sub-freezing temperatures are possible,” NWS warned, adding “these conditions could kill crops and other sensitive vegetation.” In terms of crops in California’s $45 billion agricultural industry, nuts (including almonds and walnuts) rank first in value and then grapes. The $6 billion nut business employs more than 100,000 people in the state.