- Author: Michael Hsu
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>- Author: Jeannette E. Warnert
The writers heard about innovations in olive oil production that have allowed California producers to minimize labor costs and maximize yield and quality by establishing super-high-density orchards. Farm manager Joe Armstrong led a farm tour, explaining amendments that had to be added to the soil before planting, the configuration of the trees in hedgerows and an irrigation system that permits application of water to the trees exactly when it is needed.
A graduate of California Polytechnic State University, San Luis Obispo, Armstrong said he choose a career in agriculture precisely because of the new technologies that make the field more efficient and productive.
"That's why I have a passion for farming," Armstrong said.
Ranch owner Chris Steele, who has farmed in Capay Valley his entire life, recognized how such innovations are brought to the farm.
"We couldn't do this without the UC system," he said.
UC Cooperative Extension advisors and specialists have worked alongside farmers to adapt the new super-high-density orchard systems. The idea was conceived in Spain and introduced into California in the 1990s. Successful use of high-density olive farming requires careful variety selection; finessed pruning, fertilization and irrigation practices; and understanding the cost-and-return for adept decision-making. This month, UCCE scientists released a new cost-and-return study specifically for farmers to use when planning new olive orchards under the super-high-density planting configuration.
- Author: Pat Bailey
The award was presented to the Aggie inventors during the finals of the three-day global iGEM (International Genetically Engineered Machines) competition in Boston. The competition, this year featuring 245 teams from Asia, Europe, Latin America and North America, challenges student teams to design and build biological systems or machines and present their inventions in the international competition.
The students had spent several months designing and building the palm-sized biosensor, which they dubbed OliView. The biosensor is equipped to quickly and easily evaluate the chemical profile of oil, providing producers, distributors, retailers and ultimately consumers with an effective, inexpensive way to ensure olive oil quality.
Verifying olive oil quality is a concern for consumers – many of whom are willing to pay higher prices for the health benefits and flavor of true, extra-virgin olive oil. And honest olive oil producers want to prevent other producers from passing off sub-par olive oil as the real deal, while retailers, distributors and producers want a quick, easy way to ensure olive oil quality.
In addition helping detect fraudulent olive oil, the students' new biosensor will also monitor for good oil that may have gone rancid with age.
The team of undergraduate students included Lucas Murray, Brian Tamsut, James Lucas, Sarah Ritz, Aaron Cohen and Simon Staley, with Yeonju Song serving as the “shadow” or alternate team member. You can tune into Aaron Cohen's recent Nov. 6 Science Friday interview during a discussion of synthetic biology.
The full story and a brief video about the new olive-oil biosensor and this stellar team of young inventors are available at: http://news.ucdavis.edu/search/news_detail.lasso?id=11076.
Reports on olive-oil quality are available at the web site of the UC Davis Olive Center at: http://olivecenter.ucdavis.edu/research/reports.
- Author: Karen Giovannini
Paul Vossen started the UCCE taste panel in 1998 receiving recognition from the International Olive Council in 2001 as the first IOC taste panel outside the Mediterranean Region. Since that time, the taste panel has been used extensively to evaluate the flavor characteristics of oils for irrigation, pest control, and cultivar typology research.
Established in 1915, the AOCS Laboratory Proficiency Program (LPP) is the worlds most extensive and respected collaborative proficiency program for oil and fat related commodities, oilseeds, oilseed meals and edible fats. Over 500 chemists in 40 nations participate.
By participating in LPP, the UCCE Sonoma Olive Oil Taste Panel is guaranteeing peak performance. They used AOCS methods for analysis of the samples and then compare their results with a large cross-section of other laboratories utilizing the same methods and samples. Regular analysis helps maintain quality control and accuracy.
Participants in AOCS tasting panels program subscribe to receive samples of specified product, olive oil in this case, then analyze them using designated methods. The top analysts receive first-place. Honorable Mention is awarded when warranted.
Paul Vossen is the Farm Advisor forSonoma & Marin Counties specializing in Specialty Crops and Olives, visit his Olives page to learn more or visit Specialty Crops and view a video.
/span>- Author: Betty Homer
In April, I read about how McEvoy Ranch located in Petaluma, California, and known for their estate-quality extra-virgin olive oil, was hosting special events and tours this spring and summer at the property, which is usually closed to the public. Needless to say, I had to go. I signed up for the May bird-watching tour, which gave attendees an opportunity to stroll through various parts of the ranch (the actual ranch is approximately 550 acres, most of which is being farmed and not accessible by the public). Although I enjoy observing birds in and out of the garden, this was my first official bird-watching tour ever.
The varied topography of the Ranch consisting of rolling hills, valleys, and numerous ponds, and beautiful and diverse gardens, attract a wide array of birds. On the tour, we observed a barn owl in its box, hummingbirds, various songbirds, some brilliantly-colored orioles which resembled Meyer lemons with wings, and two very impressive and imposing vultures sunning themselves atop tall trees. In between bird-watching, we got to visit the olive orchards and gardens on the property. Wherever I go, my perennial favorite is the edible garden, so I was delighted to visit two of their gardens where ornamental flowers were/are integrated with edible plants and espaliered fruit trees (see pictures below). Albeit beautiful, these gardens are not simply for display. The Ranch uses the fruit from their citrus trees and the lavender from their lavender berm, to produce various products which they sell.
Tours and events at the Ranch continue throughout the summer and vary in both price and theme. The last I read, there will be, at minimum, orchard walks and olive mill tours, a jam-making workshop, a wreath-making workshop, a guided walk through owner, Nan McEvoy’s private sculpture garden, and a cooking demonstration and garden tour with the Ranch’s head chef. For more information, see http://www.mcevoyranch.com/.