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Want to Learn More about Mosquitoes and Ticks?
Want to learn more about mosquitoes and ticks? UC Davis doctoral student and medical entomologist...
UC Davis doctoral student and medical entomologist CC Edwards dragging for ticks at Bodega Bay.
Mixed up too much of a pesticide? Now what?
You bought a pesticide product that needs to be mixed with water before applying. Did you...
UC ANR publishes first-ever manual on olive production for oil
Growers, UC Cooperative Extension researchers offer guidance on producing high-quality olives
Facing a deluge of lower-price products from Europe, the California olive oil industry is doubling down on its clear-cut competitive edge: the consistent and bona fide quality of its oil.
“Olive Production Manual for Oil,” a new book published by University of California Agriculture and Natural Resources, aims to help California olive growers maximize that advantage.
“It's a tough market to compete in, but I think the way to win for California is to compete on quality,” said book co-editor Selina Wang, a UC Cooperative Extension specialist in the UC Davis Department of Food Science and Technology. “The quality of California olive oil is unmatched, but you can't make good quality olive oil with bad fruit, so the goal is to get more fruit from the trees – and for the fruits to be high-quality fruit.”
The 273-page manual, available for purchase online, is the first of its kind in the U.S. While some parts of the book are specific to California (which grows nearly all of the olives for domestically produced olive oil), most of the material would be useful to producers in other states, Wang noted.
“Through our conversations with growers, it became clear to us that a manual like this – not a scientific publication but a manual that is easy to follow, written in language that is accessible, and with pictures and illustrations – would be really helpful to the growers,” she said.
Growth of California olive oil industry necessitated creation of manual
Aside from a book focused predominantly on table olives and another on organic olive production (by UCCE farm advisor emeritus Paul Vossen), there was no one-stop, comprehensive resource on the bookshelf for oil olive growers. The need for such a manual had become more acute as oil olives replaced table olives in California orchards during the last 20 years.
Whereas harvesting by hand was historically cost-prohibitive, the introduction of super-high-density planting systems in 1999 made oil olive production more economically feasible. Mechanical pruning and harvesting of new cultivars (Arbequina, Arbosana and Koroneiki) – specifically bred for these densely planted orchards – led to the rapid expansion of oil olives in the state. According to a U.S. Department of Agriculture report, California olive oil production jumped from 2 million pounds in 2006 to an average of 21 million pounds in 2021–23.
With about 37,000 acres of oil olives planted across California, the Olive Oil Commission of California saw the need to support the production of this manual. Championed by Dan Flynn, founder and executive director emeritus of the UC Davis Olive Center, Wang and co-editor Louise Ferguson outlined the contents of the book. They then sought out a mix of growers and industry professionals and UCCE advisors and specialists to write its chapters.
“Most of the information is data-based, from people who are working with the olives,” said Ferguson, a UC Cooperative Extension pomologist at UC Davis. “This is the first data-based olive oil production manual we've had.”
Manual infused with firsthand insights, practical recommendations
Hard-earned experience taught growers a valuable lesson that is conveyed in the book – the need to hand-prune. While mechanical pruning helps control the size of the trees, some hand-pruning is still required to allow light to filter to the leaves. Failing to do so leads to a dramatic decrease in yield.
“That happened in many of the orchards that were inexperienced in these new cultivars and new super-high-density planting systems,” Ferguson said.
She added that other key topics in the manual include irrigation management in a water-constrained state, nitrogen management, harvest timing and orchard site selection. Choosing a good spot for planting is crucial in this era of extreme climate volatility, Ferguson noted, as olive trees are significantly affected by temperature shocks in spring (fruit set) and fall (harvest).
For Wang, another overarching theme in the manual is the importance of testing. Testing the soil, water and leaves provides critical data that growers can use to adjust their inputs and production practices for optimal profitability.
“You may spend a couple hundred dollars on the lab work, but it will pay off, for sure – you're going to increase the health and productivity of your trees,” Wang explained. “Oil olive growers are paid based on the oil content in their fruit; you not only want to have a lot of fruit on the trees, you want to make sure that your fruit are accumulating oil.”
California oil olive growers, practices continue to evolve
Wang and Ferguson hope their book will help California producers compete more effectively in the global marketplace. Currently, about 90% of the olive oil consumed in the U.S. is imported from Mediterranean countries, due primarily to the lower price point. In that region, producers tend to harvest riper olives that produce oil at a greater volume but lesser quality.
In contrast, California growers harvest earlier and produce oil that is higher quality (with more flavor and more antioxidants) and far exceeds accepted standards for “extra virgin olive oil.”
According to Wang, California olive oil mills have nearly maximized their efficiency, and the growth opportunity for the industry is in the orchards: to optimize practices to produce more fruit, and to plant more trees. Wang said the new manual can help on both fronts.
“Just like for other crops, focusing on quality – while increasing efficiency and productivity, and therefore profitability – is the name of the game,” she said.
Ferguson also stressed that knowledge continues to evolve and urged growers to reach out to the editors and chapter authors with their experiences.
“Most of the authors are in California and they're working,” she said. “So if you start to notice things that are different, or you want more information or something is not clear, the authors are available.”
The manual can be purchased at https://anrcatalog.ucanr.edu/Details.aspx?itemNo=3559.
/h3>/h3>/h3>/h3>Praying or Preying or Peering
Praying, preying, or peering? This female praying mantis, a Stagmomantis limbata, selects a...
A female praying mantis, Stagmomantis limbata, poses for a portrait in a Lantana patch in a Vacaville garden. (Photo by Kathy Keatley Garvey)
Water discussion on Sept. 29 flows from LA art exhibit
Communities in Los Angeles and around California face a variety of water challenges ranging from access to clean, affordable water to water supplies threatened by a changing climate.
The public is invited to a free event featuring a panel discussion of the past, present and future of Los Angeles water. The water discussion will be part of the closing reception for the art exhibit “What's On Tap: LA's Water Story…Source to Spigot” at El Tranquilo Gallery in Los Angeles on Sunday, Sept. 29.
“I hope that people come away understanding that our relationship to and stewardship of water in LA is not only a critical part of our past history, but essential to determining our region's future as well,” said Edith B. de Guzman, UC Cooperative Extension specialist for water equity and adaptation policy with UC Agriculture and Natural Resources and UCLA Luskin Center for Innovation.
The panel will be moderated by UCLA Public Policy Professor Megan Mullin. Panelists will include de Guzman; Amanda Begley, watershed senior program manager for TreePeople; Conner Everts, facilitator for the Environmental Water Caucus, executive director of the Southern California Watershed Alliance, and co-chair of the Desal Response Group; and Mark Gold, director of water scarcity solutions for the Natural Resources Defense Council.
The discussion will be followed by a blind water tasting. Participants will be able to taste how the flavors of three brands of bottled water compare with each other and Los Angeles Department of Water and Power tap water.
“Thus far, many people have chosen LADWP tap as their favorite compared to the bottled brands,” de Guzman said. “So another hope I have is that people will come away with greater appreciation and trust of tap water.”
The art exhibit, curated by Edith and Jolly de Guzman, highlights five distinct water themes that affect Southern California communities – local water, imported water, tap trust, human right to water and affordability.
The Zanja Madre, a Spanish-era aqueduct that moved water from the Los Angeles River to the pueblo of Los Angeles between 1781 and 1904, once ran past the gallery location.
The “What's On Tap: LA's Water Story…Source to Spigot” exhibit will be open from 11 a.m.-3 p.m. Friday through Sunday, Sept. 27-29, with the closing reception 3-6 p.m. on Sunday, at El Tranquilo Gallery, W-19 Olvera Street, Los Angeles 90012. The panel discussion will begin at 4 p.m. The reception will include live music by Shoshana Ben-Horin.