Unusual Weather Could Be Problematic for California Olive Crop

A warm winter followed by several spring cold snaps have led to fewer olive trees blooming in central California.

By Daniel Dawson
Jun. 11, 2018 10:27 UTC

Some unusu­ally hot win­ter days, cou­pled with a recent spring freeze, have affected how olive trees are bloom­ing so far this year in California.

This has led some olive pro­duc­ers to have an increas­ingly pes­simistic out­look on this year’s yield, which, accord­ing to an unof­fi­cial esti­mate from the California Olive Oil Council, may be 25 to 35 per­cent lower than last year.

It’s like the trees are con­fused as to when it is spring. It’s also resulted in a lower bloom than expected over­all.- Phil Asquith, Ojai Olive Oil

Overall we’re a lit­tle on the pes­simistic side. The bloom, on the whole, has been pretty poor, many orchards actu­ally have a very light, to next to no bloom at all,” Dani Lightle, a coop­er­a­tive exten­sion orchard sys­tems advi­sor for Glenn County, told the agri­cul­tural news site Agnet. There’s an orchard here or there that looks pretty good, but on the whole, it is a lit­tle bit dis­mal.”

Part of the decrease has been attrib­uted to many of the state’s olive grow­ers enter­ing an off year after a good har­vest last year. However, both farm­ers and sci­en­tists agree that the erratic weather pat­terns have been a fac­tor as well.

I think the frost was prob­a­bly one fac­tor,” Lightle told Olive Oil Times. In this area, bloom was poor in both Glenn and Tehama coun­ties in most orchards that I observed.”

Steve Sibbett is a farm advi­sor emer­i­tus at the University of California at Davis. He said that while he has not been actively fol­low­ing the weather effects on 2018 crops, tem­per­a­ture fluc­tu­a­tions in the late win­ter and spring neg­a­tively affect olive tree blooms.

Late win­ter and early spring frost dam­age devel­op­ing fruit buds,” he told Olive Oil Times. Such an event occurred this past February fol­low­ing a warm­ing spell that encour­aged growth to begin. How much dam­age, if any, is unknown to me and is likely vari­able due to area.”

Phil Asquith of Ojai Olive Oil, which is located near Santa Barbara in south­ern California, said that he noticed the impact tem­per­a­ture fluc­tu­a­tions had on his olive trees. He said that the fluc­tu­at­ing tem­per­a­tures had caused some trees to bloom nearly two months ear­lier than oth­ers.

Something has affected the bloom here, and we’re see­ing a strange phe­nom­e­non. Some of our trees bloomed nor­mally, and some about six weeks later,” he told Olive Oil Times. It’s never been in batches like that, usu­ally all at once. It’s like the trees are con­fused as to when it is spring. It’s also resulted in a lower bloom than expected over­all.”

This year’s tem­per­a­ture fluc­tu­a­tions are sim­i­lar to what hap­pened in 2006, which was one of the low­est crop sizes for olive grow­ers in the past quar­ter-cen­tury, accord­ing to Lightle. However, she said it is still too early to tell if the unusual weather pat­terns this year will dam­age the crop to the same extent.

We actu­ally saw a sim­i­lar sit­u­a­tion around 2006 where there was unsea­son­ably warm weather fol­lowed by an extended freeze period, sim­i­lar to actu­ally what we saw this spring,” she said.

Louise Ferguson, the direc­tor of the Fruit and Nut Information Center at UC Davis, said that California’s cli­mate is chang­ing and that tem­per­a­ture fluc­tu­a­tions dur­ing the spring and autumn are likely to con­tinue tak­ing place.

Yes, there will be more tem­per­a­ture fluc­tu­a­tion, [such as a] late warm fall with sud­den freezes,” Ferguson told Olive Oil Times. And erratic warm­ing fol­lowed by cold in the spring will dam­age early bloom and fruit set.”

Ferguson also said that there was very lit­tle that farm­ers can do to mit­i­gate the effects tem­per­a­ture fluc­tu­a­tions other than to plant cli­mate appro­pri­ate cul­ti­vars and not to irri­gate trees too late into the fall.

Richard Meisler of San Miguel Olive Farm agrees that grow­ing the appro­pri­ate vari­etals for each region of California can mit­i­gate the dam­age caused by these cli­mate fluc­tu­a­tions. His olive trees are located in west­ern-cen­tral California, which has a unique micro­cli­mate, and he has not noticed a lower bloom than nor­mal.

San Miguel weather is warmer and colder than sur­round­ing areas. We call it a micro­cli­mate,” he told Olive Oil Times. Our trees are the proper vari­etals for the Central Coast cli­mate. They can tol­er­ate below freez­ing tem­per­a­tures to a degree.”

Meisler also pointed out that each part of the state has a slightly dif­fer­ent cli­mate. Therefore, there is no sin­gle vari­etal or set of strate­gies that can be applied uni­formly.

On a farm in Paso Robles, 10 miles from San Miguel, the cli­mate is just a lit­tle dif­fer­ent,” he said. “[This year, their] olives are larger than ours, and their trees are loaded. Mother Nature tells the story,” Meisler said.

The California Olive Council will have a board meet­ing on June 12. One of the top­ics that may be dis­cussed is the dam­age caused by this year’s unpre­dictable weather and what impact it may have on the over­all olive yields.


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