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LinkedInPosts Tagged: Louise Ferguson
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.
NIFA funds $3.8 million project to find climate-resilient pistachio trees
Growers invited to participate in study by sharing their experiences
A multi-state team led by Patrick J. Brown has been awarded nearly $3.8 million over the next four years for a project to improve pistachio production as the industry faces warmer winters and scarcer water.
“We are at this unique point in history where we can do this,” said Brown, an associate professor in the UC Davis Department of Plant Sciences.
The project aims to ensure the industry can thrive in coming decades despite the challenges faced. Growers are invited to participate in the study, sharing what they already are trying in their own fields or supporting any aspect of the project. To discuss the possibilities, contact Brown at pjbrown@ucdavis.edu or (530) 752-4288.
The project includes research to ensure pollination, experiments to calculate irrigation needs amid water shortages, creating tools to improve public breeding programs, developing more efficient harvesting equipment, and economic analyses to ensure future pistachio cultivation is economically rewarding. Researchers hope to offer a guide for growers deciding whether to plant new orchards or remove existing ones.
“The success of California's pistachio industry, which is the top producer of the nuts in the world, has always relied on a strong collaboration between UC researchers and pistachio growers,” said project participant Florent Trouillas, a UC Cooperative Extension specialist in the UC Davis Department of Plant Pathology. “Research efforts must continue to address enduring and new challenges, improve sustainability and ensure the profitability of pistachio farming.”
The tasty, green nuts have blossomed into a $5.2-billion industry in California, thanks to their greater tolerance of dry lands and salty soils. The project aims to further improve their climate resilience by finding a rootstock that can thrive despite growing water scarcity and declining water quality projected over the next half-century. With millions of genetically distinct pistachio trees growing in the state, "we already have out there what may be the industry's next great rootstock," Brown said. "It's probably in some grower's field already. We just have to find it."
Researchers seek to pair that new rootstock with high-yielding scions – the producing part of the tree grafted onto the rootstock – to develop new combinations that can thrive in the different conditions across the state.
Trouble with “boy meets girl”
Pistachios, like many other tree crops, have male and female trees, and they require hundreds of hours of wintertime temperatures below 45 degrees Fahrenheit for the trees to flower in the spring. Wind blows the pollen from male flowers to female flowers, creating nuts.
Complicating the timing: Boy flowers and girl flowers generally require different amounts of winter cold to bloom. After a sufficiently cold winter, boys and girls flower together. But if the winter is warm, most of them will flower at different times, reducing pollination.
That happened in the winter of 2014-15, which saw unusually warm winter temperatures. The following fall, farmers harvested only half their expected crop, losing more than $1 billion, Brown said. Climate change is expected to provoke progressively warmer winters in the future, on average.
An additional complication: The boy scions come from a single variety, or cultivar, and the girl scions come from another single cultivar. "In California part of the problem is that we have been relying on a single male and single female cultivar," Brown explained.
A key part of this project will be to test new scions that can pollinate efficiently despite warmer winters. “We now have additional male and female scions released in the last 10 to 15 years, but we need more information on their chill requirements,” Brown said.
Growing importance of pistachio sector
With nearly 520,000 acres planted in California in 2021, pistachios are the fastest-growing tree nut crop in the state. Growers have doubled their plantings over the past decade, due to pistachios' drought tolerance and higher gross returns compared to other nuts, experts report. California dominates the industry, growing 99 percent of the nation's crop and nearly 60 percent of the world's crop, employing people in 47,000 full-time-equivalent jobs and creating $5.2-billion of total economic impact in 2020, according to American Pistachio Growers.
Brown's team is part of a wider effort at UC Davis to support the sector's growth and adaptation to climate change. Other department members participating in the project include co-directors Louise Ferguson, a UC Cooperative Extension pomologist, and Richard W. Michelmore, a distinguished professor and director of the UC Davis Genome Center. Also participating are Giulia Marino, a UC Cooperative Extension specialist; and Grey Monroe, an assistant professor.
Other UC Davis participants include Trouillas and Brittney Goodrich, a UC Cooperative Extension specialist in the Department of Agricultural and Resource Economics. The project also includes researchers from UC Merced, New Mexico State University and Purdue University.
The four-year project was among nearly $70 million in Specialty Crop Research Initiative grants awarded this fall by the National Institute of Food and Agriculture. The Department of Plant Sciences landed three of the 25 grants.
Read the NIFA grant summary.
Para botanas las aceitunas son de lo mejor
Las aceitunas de mesa siempre han sido un alimento básico en la charola de las botanas de mi familia en el otoño, por lo tanto tomé nota tras escuchar la triste noticia: el costo de la mano de obra está acabando con la industria de las aceitunas de mesa. Los productores de aceitunas de mesa gastan más de la mitad de su ingreso bruto en el pago de la cosecha a mano de sus cultivos.
“Es una ecuación que no tiene sentido”, dice Dennis Burreson, productor y director de investigación del Comité de Aceitunas de California. “No podemos sobrevivir si estamos gastando más de la mitad de nuestro ingreso en mano de obra".
La cosecha mecánica es muy común en un sinnúmero de cultivos, incluyendo el las aceitunas para elaborar aceite de oliva. Pero ¿qué hace que sea tan difícil cosechar mecánicamente las aceitunas de mesa?
Éstas se magullan fácilmente y una vez magulladas no se curan bien. Además, las aceitunas de mesa se cosechan cuando no están maduras, a diferencia de las aceitunas para aceite de oliva que se coechan ya maduras; por lo tanto, se necesita más fuerza para desprenderlas del árbol. Y luego hay que pensar en las copas de los árboles: los olivos que producen aceitunas de mesa tienden a ser ralos, lo cual complica la recolección mecánica, mientras que los olivos para elaborar aceite, son muy densos.
Visite una típica huerta de aceitunas de mesa y podrá ver el problema. Es muy difícil para un agitador mecánico hacer caer la fruta de un árbol que sólo se bambolea, especialmente cuando ya es difícil desprender la fruta. Además, los troncos de los olivos se ponen nudosos con la edad (igual que nosotros), y si una máquina frota la corteza el árbol, se puede exponer el árbol a enfermedades.
Científicos e ingenieros han tratado por décadas de crear un cosechador mecánico viable. Al igual que con los primeros intentos, unas cuantas versiones diseñadas y probadas a mediados de los años 90 no dieron resultado porque no recolectaban ni recogían suficiente fruta de alta calidad. Pero los esfuerzos más recientes se muestran más prometedores.
Las dos tecnologías principales de cosecha son “cabezas recolectoras en contacto con el dosel” (se parece a un enorme cepillo para el cabello) y el agitadoes del tronco. La cosechadora de cabezales puede usarse en huertas que se han podado en hileras, y también en huertas de alta densidad, diseñadas por Ferguson y su equipo, que son similares a las huertas de olivos para aceite. La tecnología del agitador del tronco puede usarse en huertas de alta densidad pero no en las huertas convencionales.
Y he aquí la buena noticia en torno a la calidad de la fruta, la pieza del rompecabezas que ahora hace que sea muy prometedora la recolección mecánica de la aceituna de mesa: incluso hasta los más entrenados degustadores no pudieron distinguir la diferencia entre las aceitunas de mesa cosechadas mecánicamente las que se cosecharon manualmente.
“Es un avance enorme porque la calidad de la fruta siempre ha sido el punto de contención”, dice Ferguson. “Jean-Xavier Guinard (científico sensorial en el departamento de Ciencia y Tecnología de Alimentos de UC Davis) trabajó con un grupo de expertos entrenados para detectar hasta el más mínimo defecto en la textura, sabor y aroma. Ellos prácticamente no encontraron diferencias entre las aceitunas cosechadas manualmente y la cosechadas de manera mecánica”.
Se planean más pruebas de sabor tanto con expertos como con grupos de consumidores. Mientras tanto, varios productores están decididos a dar el primer paso. Burreson, por ejemplo, plantó 120 acres de aceitunas de mesa en setos de alta densidad que Ferguson ayudó a diseñar. Y en unos cinco años, sus aceitunas estarán listas para ser cosechadas.
Por lo tanto, si usted disfruta de las aceitunas de mesa, cruce los dedos , pero de manera literal ya que es difícil mantener los dedos cruzados cuando se comen aceitunas a la vieja usanza: colocando una en cada dedo de las manos.
Preparado por Diane Nelson
Adaptado al español por Norma De la Vega
Keeping olives on the table
![3505 Plate 01 03[1]](http://ucanr.org/blogs/food/blogfiles/5202.jpg "3505 Plate 01 03[1]")
“That’s a ridiculous equation,” says Dennis Burreson of Orland, grower and chairman of the research committee of the California Olive Committee. “We can’t survive if we’re spending more than half our gross returns on labor.”
“I think mechanical harvesting will soon revolutionize the table olive industry,” said Ferguson, pomologist with the UC Davis Department of Plant Sciences and director of the UC Davis Fruit & Nut Research and Information Center.
Mechanical harvesters are commonplace for countless commodities, including olive oil olives. What is it about table olives that make them so hard to mechanically pick?
They bruise easily, for one thing, and bruised olives don’t cure well. Plus, table olives are harvested while still immature – unlike the more mature olive oil olives – so it takes more force to knock them off the tree. And then there is the tree canopy: Table olives trees tend to be wispy, less accommodating to mechanical harvesting than the high-density hedgerows you see in olive oil orchards.
Visit a typical table olive orchard and you will see the problem. It’s hard for a mechanical shaker to clean fruit off a tree that just sways, especially when that fruit is hard to dislodge in the first place. Plus, olive tree trunks get knobby with age (like the rest of us). If a machine rubs the bark off those knobs, it opens the tree to disease.
Scientists and engineers have been trying for decades to come up with a viable mechanical harvester. As with earlier attempts, a few versions designed and tested in the mid-90s didn’t pan out because they didn’t remove and capture enough high-quality fruit. But more recent efforts are showing great promise.
The two leading picking technologies are “canopy contact harvesting heads” (it resembles a huge hair brush) and trunk shakers. The canopy contact harvester can be used in existing orchards when they are pruned into a hedgerow and can also be used in the new high-density orchard Ferguson and her team designed, modeled after olive oil orchards. The trunk-shaking technology can be used in new high-density orchards but not in conventional orchards.
And here is the good news on fruit quality, the piece of the puzzle that now makes mechanical harvesting so promising: Even trained testers couldn’t tell the difference between manually and mechanically harvested table olives.
“That’s huge because fruit quality had always been a sticking point,” Ferguson says. “Jean-Xavier Guinard (sensory scientist with the UC Davis Food Science and Technology) worked with an expert panel trained to detect even the slightest defect in texture, taste, aroma – the works. They detected virtually no different between olives that were manually and mechanically harvested.”
More taste tests with both expert and consumer panels are in the works. In the meantime, several growers have decided to take the plunge. Burreson, for example, has planted 120 acres of table olives in the high-density hedgerows Ferguson helped design. In about five years, his olives will be ready for harvest.
So keep your fingers crossed as you enjoy your table olives, figuratively if not literally. It’s hard to keep your fingers crossed if eat them the old-school way, one at a time off each finger and thumb.
