- Author: Saoimanu Sope
A new avocado, one that complements the widely known ‘Hass,' will hit the world market soon. The ‘Luna UCR' variety (trademarked and patent pending) has several characteristics that should be of interest to both growers and consumers, said Mary Lu Arpaia, University of California Cooperative Extension subtropical horticulture specialist based at UC Riverside.
From the grower perspective, the tree is about half the size of the leading variety while producing approximately the same yield per tree as ‘Hass,' meaning that growers could plant more trees per acre, therefore increasing yield. It also makes harvesting easier and safer.
Another advantage is the flowering behavior of the tree. Avocado trees are categorized into either Type A or Type B flower types. It is generally accepted that you need both flower types in a planting to maximize productivity. The ‘Hass' is an “A” flower type and ‘Luna UCR' is a Type “B.”
This is a potential boost for growers since the current varieties that are “B” flower types ripen green and generally receive lower prices for the grower. Similar to ‘Hass,' however, the ‘Luna UCR' colors as it ripens.
“Hopefully, it will receive similar returns to the ‘Hass' once it is an established variety,” Arpaia added.
Fruit breeding is a long-term process that she has navigated by building upon the work of her predecessors. Of course, Arpaia has had strong support from colleagues as well, including Eric Focht, a UC Riverside staff researcher and co-inventor of ‘Luna UCR.'
“We had been looking at ‘Luna UCR' for some time and it was always a very good eating fruit,” Focht said. “After the 2003 release of ‘GEM' (registered and patented as ‘3-29-5', 2003) and ‘Harvest' (patented as ‘N4(-)5', 2003) varieties, ‘Luna UCR' was always the top contender for a next release due to the small, narrow growth habit, “B” flower type and the fruit quality.”
“It's a very nice-looking fruit as well and seemed to be a pretty consistent bearer from year to year.”
A glimpse at how it all started
In spring 1996, Arpaia took over the UC Avocado Breeding Program following Guy Witney who led the program from 1992 to 1995, and Bob Bergh whose initial efforts in the 1950s were foundational in the inception of ‘Luna UCR.'
Arpaia recalls the first trials in the early 2000s of ‘Luna UCR,' which were tested alongside other promising selections from the Bergh program. “There were a lot of varieties that didn't perform well, some of which had poor storage life, an important trait that we need if we are going to get the fruit to consumers across the country,” said Arpaia.
The original seed and selection were planted at the Bob Lamb Ranch in Camarillo, and originally advanced trials of the ‘Luna UCR' variety were planted in four locations: UC Lindcove Research and Extension Center in Tulare County, UC South Coast Research and Extension Center in Orange County, a privately owned farm in San Diego County and another one in Ventura County.
The RECs are among the nine hubs operated by UC Agriculture and Natural Resources to support research and educate the public on regional agricultural and natural resource challenges.
ANR Research and Extension Centers become vital
Unfortunately, the 2017 Thomas Fire burned the avocado trees in Ventura, said Arpaia. After a change in management, the trial located in San Diego County was also terminated, leaving the two trials at Lindcove and South Coast REC.
“South Coast REC has a long history of supporting research and extension activities of high value crops important to California, including avocados,” said Darren Haver, director of the South Coast REC, which was often used to show growers the new varieties that were being developed.
“Many of the REC staff have worked with the avocado-breeding program researchers for more than two decades and continue to work closely with them to ensure the success of new avocado varieties, including ‘Luna UCR',” he added.
In addition to the support provided by South Coast and Lindcove RECs, Arpaia said that UC Kearney Agricultural Research and Extension Center in Fresno County – another UC ANR facility – made it possible for her team to conduct critical postharvest and sensory research, and consumer testing of the fruit, which included up to six-week trials of fruit ratings for storage life and taste.
“UC ANR has played an important role in our ability to not only identify ‘Luna UCR', but in preparing it for the world market, too,” she said.
Preparing to share with the world
Since 2015, Focht had been collecting data for the patent application. Now that he and Arpaia have successfully patented and trademarked ‘Luna UCR,' they are preparing to expand production by engaging interested growers with the commercial partner, Green Motion who is based in Spain.
“Green Motion contracted for 1,000 trees to be generated by Brokaw Nursery and those trees are currently being distributed, with earliest field plantings likely taking place in fall,” explained Focht.
Focht also said that Mission Produce, based in Oxnard, CA has contracted to graft over a small number of “B” flower type pollinizer trees to the new ‘Luna UCR' variety, possibly making way for a small number of avocados to be available the following year.
Once planted, the avocado trees will come into “full” production in about five years.
- Author: Tiffany Dobbyn, UC Davis
Researchers identify key markers to help professional retail buyers choose authentic products
Avocado oil has become a popular choice for many people in recent years because of its heart-healthy benefits and versatility in cooking. However, not all avocado oil products on store shelves are created equal. Some products are labeled as “pure” avocado oil when they contain other oils or additives. No enforceable standards defining the chemical and physical characteristics of avocado oil exist yet.
Researchers at the University of California, Davis, analyzed samples of 36 private label avocado oil products and graded them based on quality and purity. Private label products are made by a third-party processor and sold under a grocery store or retailer brand label. Their findings, published in the journal Food Control, show that 31% of the samples tested were pure, and 36% were of advertised quality. Quality refers to whether the oil is fresh or has gone bad due to aging, heat or light exposure. For purity, researchers measured fatty acids, sterols and other components that differentiate avocado oil from other oils.
The study included oils purchased from 19 retailers in the U.S. and Canada with various price points. They found that lower-priced oils were more likely to be tainted with other oils.
“We found that low-cost products indicate a higher probability for adulteration, but high cost didn't guarantee purity or quality,” said Selina Wang, associate professor of Cooperative Extension in the Department of Food Science and Technology. She and Hilary Green, a postdoctoral researcher at UC Davis, co-authored the paper.
Researchers also identified certain chemical markers in avocado oil that professional retail buyers can use to make more informed decisions when it comes to choosing suppliers. This way, consumers can feel confident about the products they buy.
This is the second comprehensive study conducted by UC Davis researchers on the quality of avocado oil sold in the U.S. The first study released in 2020 found that many of the test samples were of poor quality, mislabeled or adulterated with other oils.
“This study demonstrates that although progress is being made in standard development since our first market study in 2020, there are still issues with purity in avocado oil and these issues extend significantly into private label oils,” Wang said.
Avocado oil standards
Since the release of the first UC Davis study, Wang said there's been a coordinated effort by researchers, industry leaders and government agencies to establish enforceable standards. The Avocado Oil Expert Group was formed in collaboration with the American Oil Chemists' Society to discuss potential standards and future research projects.
Wang's research group has been studying how natural factors like different types of avocados, harvest times, geographic origins and processing methods could affect the chemical composition of avocado oil. They want to create standards that will accommodate natural variations while detecting any adulterations.
Wang hopes that the study's findings will contribute to the establishment of standards that benefit both consumers and avocado oil producers who want to compete in a fair market.
“I'm very optimistic for the future of the avocado oil industry,” Wang said. “It's a high-value product with high consumer demand, similar to what I saw with olive oil 10 years ago. Olive oil quality and purity have improved significantly, which is where I see avocado oil going, if we can establish fair standards and eliminate fraudulent products.”
- Author: Lauren E. Parker, USDA Climate Hub
- Author: Tapan Pathak, UC Cooperative Extension specialist
CalAgroClimate web tools help farmers prepare for frost events
A cold snap damaged almond blossoms across the Central Valley, resulting in more than $44 million in crop insurance claimsin late February 2018. A multi-day frost event wiped out roughly 75% of California's citrus crop and severely damaged avocados in January 2007. Frost can damage crops, impact growers' bottom lines and drive up food prices for consumers. With advance notice, farmers may be able to use heaters, wind machines, irrigation and other tactics to lessen some of the impacts of cold weather, such as damaging near-ripe citrus fruit or killing the bloom in almonds.
CalAgroClimate is a new farmer-focused website that can help growers anticipate weather-related risks and make plans for taking defensive action. Growers and crop consultants can use CalAgroClimate's crop and location-specific tools and resources to help prepare for upcoming frost events. The website's tools can also support on-farm decisions for managing heat, crop development and pests.
Future holds less frost
The risk of frost damage to crops and the need to prepare for that risk is top-of-mind for many farmers today, but will it always be so? To examine what climate change might mean for future frost risk, researchers at UC Davis, UC ANR and the USDA California Climate Hub conducted a study examining the incidence of temperatures below multiple “frost thresholds” during the months of critical development phases for three frost-sensitive California crops: almonds, avocados and navel oranges.
The researchers found that even during the coldest winters and springs, the incidence of frost exposure declined under projected mid-21st century climate conditions by more than 50% for almonds and oranges, and by more than 75% for avocados. While farmers in 2050 will not find frost risk to completely be a worry of climates past, they will not have to contend with the same frost concerns that farmers face today.
Few aspects of climate change are considered “positives,” and although the warming winters and springs that result in reduced frost temperatures could also come with increased pest pressure, reduced chill accumulation and other challenges, the reduction in frost exposure is a silver lining.
However, until this frost-free future arrives, growers still need to be prepared to protect their orchards from frost. To assess frost risk for the next seven days for your location, check out the new interactive Frost Advisory Tool at CalAgroClimate.org.
- Author: Ben Faber
If you see significant leaf drop in your groves due to excessive heat, the following actions are recommended:
- As soon as possible, whitewash branches exposed to the sun with special attention paid to branches on the west and south sides of the tree.
- Trees that lose a significant portion of leaves cannot efficiently move water, therefore restrict irrigation amounts to ensure you avoid creating wet, soggy conditions that can lead to root rot. It's best to irrigate less frequently and with smaller amounts of water.
- Do not prune your trees — leave hanging leaves in place to protect the tree from sunburn. Once new tree growth has occurred (in the next 3 – 6 months), pruning can take place on living wood.
- Adjust fertilization as you would with a frost-damaged tree: reducing the amount of fertilizer until the tree is re-established. If you see signs of a particular nutrient deficiency, adjust fertilization accordingly.
For more information about managing heat in avocado groves, growers can view the following articles on the California avocado growers' website:
- Author: Mike Hsu
Partnership with Esperanza Education Center provides blueprint for other adult transition programs
For students at Esperanza Education Center, an adult transition program serving students with disabilities in south Orange County, there was something deeply satisfying about handpicking 2,000 pounds of avocados.
“There's a tangible, visual element where you're like, ‘Wow, I did that – I did it, I can see it, I can feel it in my bones and my muscles,'” said Ray Bueche, principal of the school in Mission Viejo, within the Saddleback Valley Unified School District. “There's a real sense of accomplishment that you're seeing in some of these students.”
Ranging in age from 18 to 22, the students are in an adult education program that helps advance their independent living skills and prepare them for meaningful work and careers. They are able to experience the thrill of the harvest – and a variety of other farming activities – through the school's innovative partnership with UC South Coast Research and Extension Center, a UC Agriculture and Natural Resources facility that supports researchers and delivers outreach and education programs.
Given UC ANR's emphasis on workforce development, Jason Suppes, a community education specialist at South Coast REC, contacted Bueche in 2019 about a potential collaboration. While Esperanza has many partnerships with retail stores and nonprofits that give students invaluable work experiences, none of them offer the farm environment that South Coast REC could provide.
“Part of developing [our students] is getting a wide range of opportunities in a variety of vocational areas,” Bueche explained. “Agriculture is one that's very hard for us to find.”
Program ‘wildly successful' from beginning
Unlike other job sites that bring the students in less frequently, South Coast REC committed to hosting the young people every week for three hours (COVID-19 measures permitting), with Suppes and colleague Tammy Majcherek leading them in planting, weeding, maintenance, harvesting and more.
“We can provide opportunities for students to learn skills that could help them potentially find employment in a garden center, in a nursery, at landscapers,” Suppes said. “The program was wildly successful out of the gate.”
Mike Seyler, an Esperanza teacher who accompanies the students to South Coast REC, has seen firsthand the positive impacts of the partnership. He said one student – who at first balked at the idea of being outside, getting dirty and performing physical labor – eventually grew to like the work and took great pride in pulling carrots from the ground and sharing them with his family.
“To physically actually ‘see' the work you did – they don't always get to do that,” Seyler said. “It was cool to see someone, who didn't necessarily like being outdoors, really enjoy it now.”
The change of pace – and place – was especially beneficial for one young woman at Esperanza. Bueche said the nature of the work and the setting helped the student grow socially, as she relished the teamwork and camaraderie needed to accomplish their goals on the farm.
“We really saw a different person come out through her experiences there – she felt more self-confident; she was more personable with people; she was talking more,” said Bueche, who added that she has leveraged the skills she gained into a paid work-based learning experience with a local retailer.
Students bring produce to school, community
All students benefit from Esperanza's partnership with South Coast REC, as surplus produce from the center's fields is donated to make healthy school lunches. In addition, students use REC-grown fruits and vegetables at their monthly pop-up restaurant, where they hone skills in preparing and serving a three-course meal.
Their peers, who harvested the produce, derive immense satisfaction from seeing the fruits of their labor go directly to the school.
“They're able to enjoy eating the stuff that they're working for,” Seyler said. “And then they see everyone else enjoying it, and I think that really translates well for these guys.”
The students also played a prominent role in an avocado sale last summer, for which they picked 2,000 pounds of produce, bagged the fruit in 10-pound bags and then distributed preorders to the public from a stand at South Coast REC. Proceeds from the event were used to purchase farm tools, shirts and other gear.
“It was an incredible success – everyone loved the avocados,” Bueche said. “The students loved it; the parents came out; community members supported it.”
Those successes illustrate the power of a strong partnership; the South Coast REC team, in fact, received the school's “Community Partner of the Year” Award for 2020-21, for persevering through the pandemic to deliver the beneficial programs for students.
Over the last two years, Suppes and Bueche – through a lot of creativity and some trial and error – have sketched a roadmap for growing productive relationships between similar organizations and adult transition programs. And after presenting those results to colleagues, other local school districts and nonprofits such as Goodwill and My Day Counts have contacted South Coast REC to provide similar experiences for community members.
