As cold temperatures swept through California in the past two weeks, growers knew action was needed. They rushed to irrigate and turn on sprinklers, since that slows the loss of heat from the orchard.
“When you look at these different techniques to mitigate frost, all it’s really helping you do is try to mitigate one to two degrees,” said David Doll, a UC Cooperative Farm Advisor for nut crops, who is based in Merced. “This was one of those storms where we saw the blob forming a week out...it allowed us to accurately forecast and apply different strategies to mitigate the damage.”
Doll and his colleagues were monitoring the weather pattern’s progress since it formed to the north in Canada, and posting advice for growers at The Almond Doctor blog. Growers also had their eyes on the forecast.
“We ran water nonstop for a week and a half prior to that, because we saw it coming,” said Don Cameron, vice president and general manager of Terranova, by phone this week. “When it gets that cold, it's hard to save your almonds.”
While irrigating can help protect some trees, Cameron said he heard of temperatures that were past help in some almond-growing regions of the state: 19 to 22 degrees at the coldest, with others at 30 and 32 degrees.
Jake Wenger, who grows almonds and walnuts near Modesto, agreed that some crops were beyond help.
“In Oakdale I heard it got down to 19. There's no crop protection in the world for that,” Wenger said.
In Fresno County, the low temperatures were extraordinary, hitting the high teens, said Ryan Jacobsen, executive director of the Fresno County Farm Bureau.
“Monday, Tuesday, and Friday nights were the three main events,” he said .”They were all three under the freezing point, the question is how low they got in that canopy there.”
The low temperatures during the freeze week can be seen in the map above from the federal NOAA weather authorities. Temperatures hit the 20s throughout the state’s almond-growing areas.
Damage Estimates, Hail, & Pollination Concerns
How bad the damage is remains to be seen, but growers and others say the early indications aren’t encouraging.
“Very few areas escaped damage in the state,” Cameron said.
Doll said damage estimates are hard to make at this juncture because it’s only been a few days, and because damage isn’t even--it’s spotty, with pockets of damage around an orchard, a county, or the state itself.
Mother Nature has not let up on growers since the hard frosts.
Following the frost came golf-ball-sized hail, Wenger said.
“It's making for an interesting bloom season, that's for sure,” he said. “Heard about some orchards in stockton, where there are no blooms left, they're just stripped off, they're done.”
Still in the forecast at the beginning of March are several days of rain.
While rain is needed, it presents more challenges for growers who will need to spray fungicide to prevent damage from disease that thrives in moisture, and it also may put a damper on bee flights.
Bees have already had fewer warm hours to fly and pollinate than is ideal, according to Billy Synk of Project Apis m., which studies bees and helps growers get the most out of pollinators.
“The bloom is fairly short, what growers call a flash bloom,” Synk said. “Typically the whole almond bloom lasts 4-6 weeks, encapsulating all the different varieties. Everything's reduced in a year that's a flash bloom--everything's in four weeks.”Synk’s advice to growers is to make sure that fungicide applications don’t make things worse for bees.
“Fungicide can be applied at night with no toxicity to bees,” Synk said. “Avoid tank mixing, don't spray any pesticide during the day, and don't spray any insecticides at all. Only spray fungicides in the evening.”
Help for Growers
“FSA staff are standing by at their local county offices prepared to help growers assess their damage and find out what programs and resources are available to help them at this time,” said Aubrey Bettencourt, executive director for USDA's Farm Service Agency in California.“If you have crops insured, call your insurance agent and get a claim filed,” Bettencourt said. “Your next call needs to be in to FSA, where we have a host of programs, whether it's loans or financial or technical assistance for growers to recover from the freeze.”
Resources for growers from the FSA can be found at the bottom of this post, in an image that can be downloaded for reference.
Insurance company outreach means that growers may hear from their insurer before they even sit down to call: that was the experience of Don Cameron, who has some acres insured.
Ceres Imaging may be able to assist growers filing claims when it comes time to estimate damage. A major almond grower customer of Ceres has used aerial imagery can detect variations in trees later in the season that correlate with bloom damage from frost.
Not Over Yet
There’s also still hope that damage may not be as bad as feared.
“Both almonds and tree fruits, you may not have as big of an adjustment as you think. You just don't know,” said Jacobsen.
“It's definitely worrisome but there's been years when you had bad weather, and had colder weather, and a very short bloom and you end up with a fantastic crop,” said Wenger. “You've got some years when you've got a two-week bloom and no one has a good crop.”
Then there’s a benefit for the growers left standing, of higher potential prices with scarce almond supply, Cameron said.
“Whoever has some crop is going to make some money, no doubt,” Cameron said. “That's the upside.”
David Doll offers growers a warning as well before they look ahead to the rest of the season: the freezes may not be done, and the trees are getting more sensitive.
“We still have another five to six weeks of susceptibility to frost,” Doll said. “It's important for people to stay on their toes...during pink bud and full bloom you're around 26 to 27 degrees as your critical temp. As you get further from dormancy that goes up to 28, 29 depending on your variety.”
“We still have five weeks to go and next week it looks like we're going to get another cold snap. People need to stay vigilant.”
FSA Resources Notice below, and downloadable at this link.
