Pacific Nut Producer Magazine

Tag: UC Davis

  • UC Davis Opens Resnick Center for Agricultural Innovation

    The University of California, Davis, celebrated the grand opening of the Resnick Center for Agricultural Innovation.

    Made possible by philanthropic support, including a lead transformative gift from Lynda and Stewart Resnick, through their foundation in 2022, the new center is housed within the UC Davis College of Agricultural and Environmental Sciences. The center builds on the university’s longstanding global leadership in agriculture with a focus on translating research into real-world impact.

    “This center represents the best of UC Davis, uniting our strengths in agriculture, engineering and environmental sciences to address challenges facing communities across California and around the world,” said Chancellor Gary S. May. “We are deeply grateful to Lynda and Stewart for their partnership and support, which expand research opportunities and drive solutions that will shape the future of agriculture.”

    Students, faculty, staff, donors and industry partners joined university leaders May 19 to celebrate the opening with a ribbon-cutting ceremony, open house and tours.

    “Lynda and I have always believed that growing more food with fewer resources is one of the most important things we can do,” said Stewart Resnick, chairman of The Wonderful Company. “UC Davis is the leading ag university in the country, and we all have a stake in giving them everything they need to continue leading on this important work. This center will train the next generation, drive practical solutions, and get this urgently needed progress to growers and communities around the world.”

    The Resnick Center reflects a broader commitment from the couple and their foundation, whose $50 million gift to UC Davis in 2022 included $40 million for the facility and $10 million to establish the Resnick Agricultural Innovation Research Fund, advancing research into sustainable uses for agricultural byproducts. Stewart Resnick also serves on the Chancellor’s Board of Advisors, underscoring the Resnicks’ longstanding commitment to the university and its mission.

    The 34,000-square-foot facility includes hands-on learning in an innovative and immersive environment that connects education to research and discovery. Experts across disciplines will work in labs equipped with robotics, sensors, data science and artificial intelligence — technologies transforming how agriculture is managed and scaled. Research efforts will focus on making agricultural systems more resilient, developing advanced technologies, maximizing sustainability through water and energy efficiencies, and expanding access to nutritious food.

    “The new Resnick Center strengthens our ability to integrate research, teaching and extension in ways that directly serve California and beyond,” said Ashley M. Stokes, dean of the College of Agricultural and Environmental Sciences. “It creates a dynamic environment where discovery, learning and community engagement come together — accelerating innovation, deepening partnerships with industry, and translating knowledge into real-world solutions. The design and flexibility of the space allow us to reimagine ideas and respond with agility to the evolving needs of our communities.”

    The center will incorporate specialized labs and equipment that bolster efforts to transform agricultural byproducts into useable materials. This work is supported by the annual competitive research grants funded by the Resnicks, through their foundation.

    Over the past three years, UC Davis researchers have explored how agricultural waste — including discarded hulls and shells from California’s iconic specialty crops like almonds, pistachios and pomegranates — can be repurposed as soil amendments, sustainable food products and low-cost industrial materials. The new facility will allow for widespread exploration of even more agricultural crops and potential uses.

    In addition to experiential learning opportunities, the facility houses The Wonderful Scholar Center, a student success hub that offers academic and career advising for more than 50 students who are attending UC Davis on a Wonderful Scholarship. With a commitment to supporting first-generation students, the Resnicks, their foundations and The Wonderful Company have awarded over 3,500 scholarships of up to $40,000, providing mentorship and tutoring support with dedicated coaches, and equipping students with the tools to succeed in college and beyond.

    “As a first-generation college student who grew up around agriculture, I came to UC Davis with a deep appreciation of what farming families are up against. The Wonderful Scholarship brought me here, and this center has shown me how research, innovation, and policy all have to work together to change the future of agriculture,” said Jose Gomez, Wonderful Scholar and second-year political science major. “What the Resnicks have built isn’t just a building. It’s a bridge across disciplines — driving research, innovation, and people forward. I intend to spend my life serving others and advancing solutions that strengthen our communities.”

    “Today marks the beginning of a new era,” Chancellor May said. “The discoveries made inside this building will extend into farms, fields, and communities around the globe, shaping a more resilient and sustainable future for agriculture.” — Story by Courtney Tompkins, UC Davis

  • AI Tool to Help Farmers Measure Real-Time Crop Health from the Field

    Leaf Monitor, a new mobile tool backed by artificial intelligence and predictive modeling, could revolutionize how farmers monitor crops and make decisions by providing real-time nutrition and leaf trait information in the field.

    “Having this information is very valuable for the farmers,” said Alireza Pourreza, associate professor of Cooperative Extension and director of the Digital Agriculture Laboratory in the Department of Biological and Agricultural Engineering at the University of California, Davis. “In five seconds, they can have a sense of how much nutrition they have in a leaf.”

    Development of the AI model was funded by the U.S. Department of Agriculture’s National Institute of Food and Agriculture’s HiRes Vineyard Nutrition multistate project and its Animal and Plant Health Inspection Service, as well as the California Table Grape Commission.

    Maha Afifi, director of viticulture research at the California Table Grape Commission, said the tool could be a game changer for the table grape industry if it leads to faster decision-making about fertilizer use. The right amount typically leads to healthier vines that produce more grapes with optimal size, weight and color.

    “The evaluation of vine nutrient status is one of our top priorities,” Afifi said. “At the same time, exploring new technology tools like this project is a high priority for us because they will be important to the future of the table grape industry.”

    Field testing

    The Leaf Monitor tool uses a handheld spectrometer to measure leaf reflectance beyond the range of light visible to the human eye.

    Once a leaf is scanned, its spectral data is uploaded to a cloud-based machine learning system designed to predict leaf traits and nutrient content. This algorithm was developed and trained by the Digital Agriculture Laboratory over five years using a dataset of thousands of leaf samples collected from California’s specialty crops, primarily grapevines and almonds. The samples were chemically analyzed to determine nutrient levels and structural leaf traits, providing the data needed to build an accurate prediction model.

    “Nutrient deficiencies in plants often go unnoticed until late in the season, by which point the damage is already irreversible,” said graduate student Parastoo Farajpoor, who is running the project. “This is why early detection is essential. Spectrometry provides a rapid and reliable way to identify these deficiencies before visible symptoms appear.”

    After a recent demonstration, Bulleseye Farms Irrigation Manager Geoff Klein said the tool could help save money and improve yields. Bullseye grows walnuts, pistachios, tomatoes, corn, wheat, rice and sunflowers in Yolo and Solano counties.

    Tailored crop management

    Currently, farmers typically take leaf samples, dry them, grind them up and send the samples off to a lab for testing, which can take up to two weeks to return results. Bullseye samples leaf tissues about three times a year.

    “Right now, it doesn’t really make sense to go out and take tissues in every single corner just because it’s expensive,” Klein said. “It’d be really cool if I could just walk out there and test a couple of different places.”

    The Leaf Monitor tool helps farmers tailor management decisions to specific areas rather than an entire field. Calibrating fertilizer use to real-time data can prevent overuse and nitrogen runoff, a financial and environmental challenge that many growers face.

    “I feel like there’s a lot of times we do need to put less [fertilizer] on, where we end up putting more, because that’s what the nitrogen removal formula says,” Klein said. “But with this app we can use less because we know the actual conditions at the time. I think it opens a lot of doors in terms of getting data back in real time and also utilizing the level of control we have with the data.”

    The app can also aggregate the scans and map out spatial patterns over a large area.

    “What we know is every field has variability that is not necessarily visible to the farmer’s eye,” Pourreza said.

    The prototype Leaf Monitor tool is free and included in a set of tools that can be downloaded on the Digital Agriculture Laboratory website. A web-based version of the tool will follow while the team continues to feed new data into the algorithm to refine the predictions. On average, it achieves about 65% accuracy across all traits, with predictions for certain nutrients, such as nitrogen and phosphorus, performing better than the overall average. Users will need to pair it with a spectrometer.

    “We need to produce more food while using less resources so we need to have some kind of monitoring system to give us precise and accurate feedback on our management practice,” Pourreza said. “This technology is growing very fast.” — By Emily Dooley, UC Davis

  • Turning Food Scraps into Opportunities

    For every juicy tomato or crunchy almond California grows, there’s a pile of pulp, hulls or scraps that often goes to waste. A new online tool, created by University of California, Davis researchers, tracks those agricultural byproducts aiming to find innovative ways to put them to use.

    The Byproduct Database, maintained by the AI Institute for Next Generation Food Systems, is an ongoing research project that includes a catalog of byproducts like fruit skins and nut shells, and potential ways to reuse them across different industries.

    Edward “Ned” Spang, principal investigator and associate professor with the Department of Food Science and Technology, said about one third of the food produced worldwide, doesn’t get eaten. The database consolidates information about food waste in one place, detailing what the various leftovers are made of and where they’re available in the state. Spang believes it could help guide decisions on reducing waste by potentially turning these materials into new products for food, cosmetics or pharmaceutical industries.

    “In the food production space, there’s a lot of edible material, or potentially valuable material, that’s been overlooked for a long time as waste,” Spang said. “So, the questions we are trying to understand include: ‘How much of this material is out there? What is it composed of? Where is it? When is it available?’”

    Tomatoes, almonds, pistachios and pomegranates

    The pilot phase of the database currently features four major crops: tomatoes, almonds, pistachios and pomegranates. As the research team continues to gather data, they will update the site to include other crops and byproducts, including wine grapes, stone fruits and citrus. In collaboration with Ilias Tagkopoulos with the Department of Computer Science, Spang is looking into developing and applying AI tools to expand the site faster and with less manual work.

    For pistachios, the website illustrates that the largest byproduct is the hull, which is often discarded, and that undersized pistachios could be a valuable resource if there was a market for it. The website helps outline the various byproducts for potential upcycling, where leftovers are transformed into new ingredients. Local companies are already developing new products using materials such as brewers’ spent grain (a byproduct of beer production), okara (a fibrous byproduct from soymilk production) and grape pomace (leftovers from winemaking).

    Researchers are looking at where food gets lost in the field and at the processing plant. With tomatoes, some get damaged on the vine, others get tossed out for not meeting quality standards. Spang said those leftovers, or side streams, are opportunities for upcycling.

    “It’s a material that’s already been cultivated, harvested and processed, so anything you do that’s economically productive means that all the resources embedded in that material, like fertilizer, water and energy, were not wasted in vain,” said Spang, who also directs the Robert Mondavi Institute of Wine and Food Science. “It is a real win-win opportunity.”

    Finding new uses

    The skin and pulp of a tomato contain lycopene, an antioxidant known for its health benefits. Users of the website can visualize where these leftover tomato parts, and its valuable lycopene, are found, helping to imagine new ways to make use of this healthy compound.

    “We expect our primary user to be entrepreneurs who are looking for new business models in upcycling, or who might have an advanced extraction technology to derive value from some of these overlooked materials,” Spang explained. “But producers and growers would also benefit as new revenue streams deliver value up and down the food supply chain.”

    The database will soon include cost estimates and economic variables to help users make more informed decisions. This will allow them to assess factors like how much lycopene is in a byproduct, its value per milligram and the costs associated with extracting it.

    New space for agricultural innovation on campus

    The research project is funded by a grant from the Resnick Agricultural Innovation Research Fund, created by a $50 million gift by Lynda and Stewart Resnick, co-owners of The Wonderful Company. Part of that donation also establishes the Resnick Center for Agricultural Innovation, currently under construction on campus, that will include a large space for biomass staging and extraction, a process to pull valuable compounds from fruits, vegetables and grain residues.

    Food waste happens, but this work is helping build a food system that wastes less and supports sustainability, which Spang hopes will excite everyone.

    “We have to be a little more creative with our food system,” he said. “We can make our current food system more productive by investigating novel upcycling ideas and processing systems that create more revenue for producers and hopefully deliver more value to consumers as well.” — By Tiffany Dobbyn, College of Agricultural and Environmental Sciences, UC Davis, tadobbyn@ucdavis.edu

  • California Walnut & Ag Industry Leader Jonathan Field Passes

    California’s agriculture industry is mourning the loss of Jonathan W. Field who served as Manager of the California Tree Fruit Agreement for over a decade, led the Walnut Bargaining Association and served as the Compliance Officer for the California and Arizona Leafy Greens Marketing Agreements and the California Cantaloupe Advisory Board.

    Field, 77, of Lincoln, California, passed away peacefully August 5, 2025, surrounded by his loving family.

    Field’s passion for agriculture began at age six when he received his first sheep on Christmas morning. A lifelong 4-H member, he spent nine months in Kenya, Africa with the 4-H and Peace Corps, teaching crop rotation and agricultural best practices. He always maintained his own sheep and cattle, fulfilling his lifelong dream of farming.

    He attended California Polytechnic State University, San Luis Obispo where he earned an undergraduate degree in Agricultural Business and then a master’s degree in Agricultural Economics from University of California, Davis.

    Field’s professional journey as part of California’s agricultural industry was as expansive as it was impactful. He began his career with California Agricultural Statistics Service and then as an economist for the California Department of Food and Agriculture (CDFA) where he worked on programs for iceberg lettuce, fresh tomatoes, carrots, celery, potatoes, cling peaches and processing pears. While at CDFA, Field wrote the first Marketing Agreement program and was the economist assigned to the first Commission laws created in California.

    In 1981, Field became Assistant Manager for the California Tree Fruit Agreement (CTFA), a conglomerate of marketing order programs representing California-grown peaches, plums, nectarines and pears. He became Manager in 1987, serving until 2000 where he championed growers, strengthened industry standards and left a lasting mark on California’s tree fruit sector. Importantly, he was integrally involved in the litigation which went successfully to the U.S. Supreme Court upholding the legality of mandatory commodity programs.

    “During the 1990s, the California Tree Fruit Agreement was extremely fortunate to have Jonathan Field as its Manager,” said Melvin Enns, a tree fruit grower-shipper who served on the CTFA Board for many years.  “Jon was well-versed in the intricacies of government regulations. He formed a diverse team of experts in the areas of merchandising, export development, communications and grower relations to create programs that complied with these directives. And, together with the 1500+ growers of California peaches, pears, plums, and nectarines, Jonathan and his team built a federal and state marketing order that was the envy of tree fruit growers in every other state.”

    Not only did Field leave a lasting impression on the California fruit industry, but he championed several causes impacting California agriculture in general. Working with a group of marketing order and commission managers (who are now retired) including:  Bruce Obbink, California Table Grape Commission; Dennis Balant, California Walnut Board; Rich Peterson, California Prune Board; Terry Stark, California Raisin Advisory Board, and Dave Riggs, California Strawberry Commission, Field was instrumental in founding the Alliance for Food and Farming, the Agricultural Issues Forum, the Minor Crop Farmer Alliance, the California Specialty Crop Council and the Buy California Marketing Agreement, or “California Grown”.

    After leaving CTFA, Field formed Paradigm Consulting Company where he worked for several organizations including as Executive Director of the Walnut Bargaining Association, a cooperative of California walnut growers.

    “Jon Field was a true representative for our industry,” said Donald Norene, Chairman of the Walnut Bargaining Association (now known as the Walnut Alliance of California.). “He was committed to empowering walnut growers with the financial information necessary to successfully negotiate a fair return for their walnut crop and his analysis was highly regarded by bankers, growers and handlers.”

    In 2007, Field began working as the first Compliance Officer for the newly formed California Leafy Greens Marketing Agreement (LGMA) and its sister organization the Arizona Leafy Greens Marketing Agreement to help ensure leafy greens growers are following stringent food safety practices. In 2012, he began performing these same functions as the Compliance Officer for the California Cantaloupe Advisory Board. Field finally retired in 2023.

    “I had known Jon for many years prior to bringing him on at the LGMA as our very first Compliance Officer,” said Scott Horsfall, former president and CEO of the California LGMA. “He was the perfect person for this role with his strong background in working with CDFA, his knowledge of marketing orders and agreements and his strong desire to help the agricultural industry through challenges. He will be missed.”

    Jon is survived by his wife, Christine, of 52 years; and children Erin, Jonathan and Heather; seven grandchildren, sister, Shirley and many nieces, nephews and cousins.  The family will provide more information about a Celebration of Life at a later date.

  • New Map to Crack the Code of Pistachio Genetics

    California produces 99% of the nation’s pistachios, generating nearly $3 billion in economic value in the state. But pistachios have been slightly understudied in part because of the lack of a high-quality map of their DNA. University of California, Davis, researchers have now generated the most comprehensive genome sequence of the pistachio, allowing plant breeders to create better — perhaps more nutritious — varieties. They’ve also detailed how pistachio nuts develop, which will help farmers manage their crop more sustainably.

    New Phytologist published the study on March 20th.

    Scientists have sequenced the DNA of pistachios before, but co-corresponding author J. Grey Monroe, an assistant professor with the Department of Plant Sciences, said this new genetic map is vastly more detailed and accurate.

    “The improvement in accuracy of the new reference genome is like going from a hand-drawn map of a landscape to a satellite image from Google Earth,” he said.

    Monroe and the research team sequenced the genome of the Kerman cultivar, the most common pistachio variety grown in California.

    Climate change challenges pistachio yields

    Pistachio trees are resilient to drought and salinity, but they require cold winters to flower properly. As climate change brings warmer winters, growers need new pistachio varieties that can thrive in higher temperatures. Warm winters, combined with the dissipation of fogs that cool California’s Central Valley, have caused significant losses for pistachio growers.

    Given that establishing a pistachio tree requires a commitment of up to 50 years, researchers said California growers are understandably concerned about the impacts of climate change on their crops.

    A nutty development

    The study also identifies four key stages of nut growth from flower to harvest, providing a complete physiological assessment, including shell hardening and kernel growth.

    “Knowing how the nut changes through development will help farmers make better decisions, like when to water their trees, leading to more sustainable pistachio production,” said co-corresponding author Bárbara Blanco-Ulate, an associate professor with the Department of Plant Sciences.

    A more accurate assessment of its development could also help provide growers better strategies for harvest and avoid issues such as insect damage and fungal infections.

    Blanco-Ulate said it was important to also detail not just the physical changes of the pistachios, but also the genetic and molecular drivers of those characteristics. The genomic sequence includes precedent-setting information on how different genes behave in nuts over the growing season.

    Nutritious nut

    Pistachios have always been a nutritious food, but researchers have now discovered the genes and pathways that influence their nutritional value. This includes insights into how protein and unsaturated fatty acids accumulate, which is crucial for both their shelf life and dietary benefits.

    “We’re getting information about how all these nutritional characteristics are gained in pistachios and how we can improve that from a management perspective,” said Blanco-Ulate.

    This understanding could help scientists breed more nutritional pistachios in the future.

    The first authors of the paper are Jaclyn Adaskaveg and Chaehee Lee of UC Davis. Other UC Davis authors include Yiduo Wei, Fangyi Wang, Saskia D. Mesquida-Pesci, Matthew Davis, Louis Ferguson, Giulia Marino, Patrick J. Brown, Georgia Drakakaki, Selina Wang and Filipa S. Grilo.

    Research was funded by the California Pistachio Research Board, the U.S. Department of Agriculture’s National Institute of Food and Agriculture and the Foundation for Food and Agricultural Research. — By Amy Quinton, UC Davis

  • Dairy and Almond Groups Partner on Healthy Soils Research

    UC Davis researchers are evaluating the use of pelletized compost made from dairy manure and almond tree twigs, to create safe, pathogen-free, value-added amendments to boost soil health.

    Building healthy soils has tremendous benefits. Increasing the amount of organic matter within the soil can improve water retention and protection, reduce erosion, sequester carbon, and improve crop yields. Increasing water scarcity and severe drought conditions make boosting soil resilience an even greater priority for California. Researchers are exploring how the environmental benefits of healthy soils initiatives can extend even further when readily available agricultural resources are used in regenerative ways.

    A team of UC Davis researchers, led by Dr. Ruihong Zhang, has recycled dairy manure and almond twig waste into a nutrient-rich, safe, organic soil amendment. The new product was created and applied, and its effects continue to be studied. The idea is that the woody material can capture nutrients in the manure and slowly release them, as needed, into the soil. Because the product is also pelletized, it can be applied to croplands and orchards with standard farm equipment. Ultimately, the researchers hope to create a new model for using recycled agricultural resources to sequester carbon and provide benefits to the soil, crops, and the environment.

    The partnership was a natural fit, as the Central Valley is home to many neighboring dairy farms and almond orchards, which have a long history of collaboration. Dairies are already major consumers of almond co-products, including hulls (used as a highly nutritious feed ingredient) and shells (used as a bedding material). With a goal of achieving zero waste by 2025, the California almond community has been actively investigating a wide variety of ways to utilize woody biomass, including twigs, pruned branches, and tree removals. Meanwhile, the dairy community has been exploring ways to expand use of manure nutrients across California’s diverse agricultural landscape.

    “Creating valuable manure-based soil amendments is an area that the dairy sector has been focusing on, but there are some challenges,” said Denise Mullinax, Executive Director of the California Dairy Research Foundation (CDRF). “We know that farmers want a soil amendment with a consistent and reliable nutrient profile. It also needs to be easy to transport and apply. That’s why we are thrilled to support this team of esteemed researchers and to partner with the almond industry on this project. Together, we’re piloting a new avenue to enhance the benefits of both manure and woody biomass.”

    The initial project was funded by the California Department of Food and Agriculture (CDFA)’s Healthy Soils Program. As the project scope grew, the researchers were awarded additional funding from the demonstration category of CDFA’s Alternative Manure Management Program. With supplemental support from the CDRF and the Almond Board of California, the research project developed to include a team of more than 20 individuals—including researchers, farmers, and industry collaborators—contributing throughout a three-year timeframe. The project includes two seasons of creating soil amendments and applying them to the orchard, and three years of studying effects on soil health, emissions, tree health, and crop yield, while ensuring food safety.

    Using composted manure from Wickstrom Dairies, the study will shine a light for future research on expanding and improving manure utilization. Like many California dairies, the farm uses a separator system to remove solids from liquid manure streams. The solids are then sun dried in rows that are turned over periodically, as a form of composting. Dried manure solids are traditionally used for bedding or are applied to dairy forage fields. For this study, a portion of the finer manure solids were co-composted with twigs from almond production and then ran through a pelletizer. Pelletizing the compost is intended to provide a more consistent blend, while creating an easy-to-use product. The pelletized compost product has now been applied to the pilot orchard for two consecutive seasons. Four treatments were used to examine differences in manure-only verses manure-twig and pelletized versus non-pelletized compost products.

    “We look forward to seeing the final results,” said Mullinax. “Dr. Zhang and her team are demonstrating that it’s possible to make a pelletized product that is safe and easy to use, while fully assessing the environmental benefits. It’s projects like this that will pave the way for implementing advanced nutrient management on a larger scale, greatly enhancing soil health and further improving water conservation and protection.”

    The research team highlighted the project by providing a virtual field day, and they plan to host another outreach event this fall. Research is scheduled to conclude in March 2022. However, longer-term effects on soil health will continue to be studied. And the final report will only be the beginning of more learnings to come.

    Potential research areas to be explored next include applications on different kinds of crops, comparing a pelletized versus granulated product, and using varying types of dairy manure solids (from different types of separators, settling basins, and lagoon solids). Additionally, the use of infrared technology versus composting will be explored prior to pelletization or granulation. All options will also need to be assessed for cost-effectiveness and potential scalability.

    The manure-twig project is part of a broader, collaborative effort to expand manure’s role in healthy soils. California dairy farmers will continue to work with researchers, state officials, and other agricultural professionals to find more ways to maximize manure’s role in building healthy soils and protecting our air, water, and climate. The possibilities for sustainable solutions are bright when farmers and scientists come together to make new use of existing resources and technologies.

    California dairy farmers will continue partnering to help make an underutilized resource an important part of a healthy-soil future.

    — By Dairy Cares

  • Whole Orchard Recycling Benefits and Incentives

    Almond Board of California — Exciting research shows that conducting Whole Orchard Recycling (WOR) in almonds can increase crop yields in subsequent orchards, provide long-term benefits to soil health (such as improved water retention and nutrient levels) and increase carbon sequestration.

    Conducted by researchers from the University of California (UC) Davis and UC Agricultural and Natural Resources, with funding in part by the Almond Board of California (ABC), this study identifies significant advantages to practicing WOR, the breadth of which are detailed in a report published in the journal PLOS ONE.

    The study spanned over a decade and compared plots within a nine-year-old orchard where WOR took place with plots where trees had been burned and their ashes tilled into the soil. At ninth leaf, researchers also tested the impact of deficit irrigation mid-growing season by reducing the amount of water applied by 20% for some of the trees.

    When the results were placed side-by-side, the plots where WOR took place consistently bested the plots where old trees’ ashes were tilled into the soil. Among other benefits, researchers discovered a:

    • 19% increase in yields at ninth leaf and 15% increase in cumulative yield over five years, 
    •  30% increase in soil water holding capacity (water retention), and 
    • 17% increase in total soil nitrogen levels. 
      • To note: Subsequent research found that additional nitrogen is needed in the first year.

    “Almond growers have long been told that implementing practices to improve soil health will provide all these benefits, but until now there had been very little data demonstrating that a focus on feeding the soil with organic matter can make a meaningful difference in yield and crop quality,” said Gabriele Ludwig, Ph.D., director of Sustainability and Environmental Affairs for the Almond Board.

    Study shows significant yield increases
    Key among the multiple positive outcomes discovered by this WOR study is the potential for increased yields. This finding not only brings good news for a grower’s bottom line, but it also has positive implications on the industry’s effort to produce “more crop per drop,” an effort it is striving to achieve as part of its Almond Orchard 2025 Goal to reduce the amount of water used to grow a pound of almonds by an additional 20%.

    “The increased water holding soil capacity that occurs as a result of Whole Orchard Recycling means that trees are subject to fewer extremes in terms of water availability, as more water is held in the upper layer of the soil where the majority of the tree’s roots are, and where tree uptake takes place,” Ludwig explained.

    Research shows that WOR increased water retention in the soil by up to 30%. While Ludwig cautioned that this data does not lend itself to a recommendation that growers can use less water if they practice WOR, it does indicate that applied water is used more efficiently by trees in orchards where WOR has occurred.

    Amélie Gaudin, Ph.D., an associate professor of agroecology in the UC Davis Department of Plant Sciences and a co-author of the WOR research report, said that by allowing more water to penetrate and the remain in the soil, WOR also reduces potential irrigation-related losses caused by runoff or evapotranspiration.

    “In plots where WOR occurred, water was more likely to reach and be used by the trees, allowing for increased yields as trees experienced less short-term stress and therefore achieved greater water use efficiency,” Ludwig said.

    A hedge against deficit-induced tree stress
    This study also demonstrates that by increasing soil organic matter, WOR helps insulate orchards from negative impacts of deficit irrigation, which involves a delicate balance between stressing one’s trees just enough to prevent too much moisture and potential for disease in the orchards with not overstressing the trees to a point where their yields and overall health are compromised. According to the research, the deficit-irrigated trees in the WOR plots maintained higher stem water potential compared to the deficit-irrigated trees in the burn plots, indicating trees in the WOR plots were less water stressed.

    “We forget that trees can get stressed enough to shut down photosynthesis, whether that’s because they can’t keep up with water demand in the hot afternoons, for a day or two before irrigation, or during harvest,” Ludwig said. “So, when the upper layers of the soil can hold more water, the trees are better buffered from those stresses.” 

    Gaudin said that by improving water holding capacity, WOR also helps orchards retain nitrogen, one of almond trees’ most necessary nutrients. This has positive implications for groundwater quality in areas where nitrogen leeching is a concern. It also may contribute to yield increases as trees in the WOR plots were shown to have greater access to nitrogen for longer periods of time.

    Another supplementary benefit, Ludwig noted, is that over time, as microorganisms in the soil break down the woody biomass, both macro- and micronutrients contained within the wood are released for reuse by the next generation of trees. This allows growers to “recycle” those nutrients so that they may be used throughout the lifetime of their newly planted orchard.

    Next steps for researchers working on this WOR research, Gaudin said, include further study of carbon sequestration and its implication for greenhouse gases, gaining a better understanding of nitrogen retention, optimizing WOR in different soil conditions and the impacts of integrating WOR with other responsible growing practices such as cover crops or anaerobic soil disinfestation.

    Support for those seeking to conduct WOR
    Growers may be eligible to receive incentive funding to conduct WOR if they apply for funds far enough in advance of conducting the practice.

    • WOR is now a practice eligible for co-funding through CDFA’s Healthy Soil Incentives Program. Payments cover about 50% of the cost of WOR, according to CDFA Senior Environmental Scientist Geetika Joshi. The next round of funding for the program begins in July 2021.
    • USDA-NRCS offers Conservation Stewardship Program funds to growers who find alternatives to burning old trees, providing $783.29 per acre for chipping (used for animal bedding or applied as mulch on another piece of ag land) and an additional $242.09 per acre for Whole Orchard Recycling. While applications are accepted year-round, funding for 2021 has already been announced. Still, growers can submit their applications now to apply for 2022 funding.  
    • For those in the San Joaquin Valley, the San Joaquin Valley Air Pollution Control District provides cost-share funds to reduce ag burning through its Alternative to Agricultural Open Burning Incentive Program. Growers participating in this program are eligible to receive $300-$600 per acre, with a maximum of $60,000 per grower. Incentive recipients are typically paid four-to-six weeks after their completion of WOR, and after an invoice has been sent to the district.

    For general questions about incentive programs, industry members may contact ABC’s Jesse Roseman at jroseman@almondboard.com.

    Those interested to learn more about how WOR may be practiced on their operation are encouraged to download or request a physical copy of the Whole Orchard Recycling Guide for California Almond Growers, created in partnership by ABC and UC ANR. Growers are also welcome to watch the     Whole Orchard Recycling Overview and Whole Orchard Recycling – A Grower’s How-To videos, which are hosted on YouTube and found on ABC’s website. Finally, UC Davis provides a robust website dedicated to Whole Orchard Recycling, which offers a deep dive into the research findings, grower testimonials, and more. 

    In addition to Gaudin, co-authors of the study include Kelsey Brewer and Emad Jahanzad of UC Davis; Brent Holtz, Sean Hogan and Cameron Zuber of UC Cooperative Extension; and David Doll, a former UC Cooperative Extension farm advisor.

  • Trials of New Almond Varieties Pay Dividends

    In the 1970s, the Almond Board of California began supporting Regional Variety Trials (RVTs) to provide a mechanism to test the performance of new varieties across the diverse almond growing regions in the State of California and to extend that information to local growers. Previous and current RVTs have been designed to evaluate new varieties or selections in a semi-commercial (20 to 40 trees per variety) manner and compare them to standard varieties such as Nonpareil, Mission, and currently accepted pollinizer varieties.

    One of the main outputs of the first two generations of RVTs was to fully document the performance of the top 14 out of 15 varieties most currently adopted in California. These first two RVTs identified good pollinizers for Nonpareil, collected key horticulture and almond quality data, and discarded many undesirable pollinizers before they were widely adopted.

    The third, and current generation of RVTs started in 2014 and is already in the process of identifying top performers. For instance, the USDA breeder recently released selection Y116-161-99, as the new variety ‘Yorizane’ variety due to the consistent novelties of the variety, including self-fertility, high yields and good kernel quality recorded in the current RVT. The current RVT brings key novelties in comparison to the previous generations such as the fact that all the trees were planted in the same year (2014), in multiple locations (Butte, Stanislaus & Madera Counties) and with statistical repetitions.

    For nearly 50 years the Almond Board has partnered with the University of California (UC) to conduct Regional Variety Trails (RVTs) that provide a mechanism by which ABC, researchers and industry members can evaluate new varieties across the diverse almond-growing regions in the state.

    Due to the contribution of these RVTs, our industry has been able to adopt a wide range of varieties that offer a versatile supply of almond kernel and confer competitive advantage to growing almonds in California. Thanks to the outputs of these RVTs, our industry counts on multiple pollen compatible varieties (i.e. Fritz, Price, Aldrich, Wood Colony, Monterey, etc) that adequately cover Nonpareil bloom. The RVTs have identified varieties that are more resistant to pests and diseases such as NOW (i.e. Price and Butte) and Hull Rot (i.e. Monterey, Carmel, and Fritz), respectively. RVT outputs have expanded our harvesting and processing operations by identifying the Sonora group (harvested 7-13 days after Nonpareil), the Price group (harvested 15-21 days after Nonpareil), and the Carmel group (harvested 29-34 days after Nonpareil), among others. Also, the data collection in these RVTs have served to group varieties by their ease of nut removal (i.e. Butte, and Price fall in the easy category while Merced falls in the difficult category), hull split date, vigor, etc.

    This investment in varietal research has resulted in the commercialization of new UC varieties in the past 20 years such as: Kester, Sonora, Sweetheart and Winters. And thanks to the RVTs and the ongoing collaboration with the USDA breeder Craig Ledbetter, we can now add Yorizane – another self-compatible variety with many intriguing characteristics — to the mix. It is the latest example of ABC research and collaboration with the UC coming to fruition, with many other new varietals potentially still in the pipeline from the current RVT.

    Understanding the benefits, trade-offs

    At The Almond Conference (TAC) 2020 breakout session in December, ABC Associate Director of Agricultural Research Sebastian Saa told growers that evaluating more self-compatible varieties like Yorizane remains a priority. Self-compatible varieties potentially require fewer pollinators in the orchard because the pollen only has to move a short distance – from one blossom to another blossom of the same tree – rather than from one blossom to another blossom a tree row or more away.

    There are other advantages, Saa said: “Self-compatible trees can be grown in blocks of the same variety, allowing for more efficiency at harvest time. ‘One shake, one harvest,’” he said.

    Many of the most recent new varieties created in California and around the world are also are self-compatible. Saa said that CA new varieties typically bloom about the same time as Nonpareil but are harvested a couple of weeks later and therefore could be viable options for growers seeking to transition to off-ground harvesting.

    During the online discussion at the breakout session, a grower asked Saa if there is an increased risk of resiliency to diseases or pests with self-compatible varieties, especially if there is less genetic diversity within an orchard.

    “If we adopt one self-compatible variety, then there is a potential risk,” Saa acknowledged, “but if we adopt multiple self-compatible varieties from different genetic background, then the risk remains low, and our resilience is improved. Our goal is to enhance variety diversification for the California almond industry by adopting better almond varieties that respond to different market demands as well as provide enhanced traits such as self-compatibility.”

    In addition to learnings around self-compatible varieties, TAC attendees also had an opportunity to hear from Phoebe Gordon, a UC Cooperative Extension orchard crops farm advisor in Merced County. Gordon manages one of the RVT sites in Madera County (others are located in Butte and Stanislaus counties). Since 2017, she and her peers have tested various pollinator varieties paired with alternating rows of Nonpareil trees.

    “We test all varieties for bloom timing, bloom profusion, hullsplit timing, yields, defects and insect damage, and observe any disease issues,” Gordon explained.

    She said early results in the RVT indicate that some of the pollinator varieties may have higher yields than Nonpareil, but cautioned that “we need to look at entire lifespan of these varieties.”

    Research requires patience

    Developing a new variety can take many years, if not decades. Craig Ledbetter, a research geneticist with the Agricultural Research Service, based at the San Joaquin Valley Agricultural Sciences Center in Parlier, was directly involved with the development of Yorizane.

    He said the first seedling was planted in 1999. Its kernel attractiveness and ease of cracking – combined with self-fertilization — quickly separated it from other alternatives, Ledbetter said. Annual tests on roller crackers also showed its kernels damage less often than Nonpareil. Then, the RVT that began in 2014 revealed Yorizane’s heavy yield potential.

    “Yorizane provides a varietal option to growers to establish a more efficient single-variety orchard,” Ledbetter explained. “As a part of the RVT, it has been evaluated in blind tests by industry personnel for kernel attributes and has been found to have excellent kernel appearance and marketing potential.”

    Limited quantities of Yorizane already are available at many of California’s leading tree nurseries.

    Partners key to long-term success

    Yorizane is just one example of the ongoing value and importance of the Almond Board’s long-term investment in research, development and real-word, in-the-orchard testing of new varietals. It is a critical partnership between the industry and the U.S. Department of Agriculture’s Agricultural Research Service (USDA/ARS), the University of California system, and private breeders and nurseries in California.

    Chuck Fleck, director of horticulture research at Sierra Gold Nurseries near Yuba City, said there are many other exciting scientific advances on the horizon. Although Sierra Gold’s variety development program is relatively young, he said its team plans to eventually release almond varieties and rootstocks that provide growers with many advantageous genetic characteristics.

    Fleck pointed to the work of two researchers – Malli Aradhya of the USDA and Tom Gradziel of UC Davis – as being especially promising. Aradhya’s has focused on helping growers overcome abiotic (atmosphere, chemical elements, sunlight/temperature, wind and water) as well as biotic (soil, floom, leaves and wood) challenges in their orchards. Gradziel is working to bring new germplasm into almonds’ fairly narrow genetic base as well as exploring alternative rootstock options to more effectively deal with abiotic and biotic issues.

    “Perennial crop breeding takes years to see successes and breakthroughs,” Fleck explained. “Because it can take decades before such successes come to light, the resulting varieties — and therefore the breeding program’s true value — is not easily discerned until long after their inception.”

    Factsheets will inform growers

    It hasn’t always been easy to efficiently communicate breakthroughs in the genetic world or promising results from RVTs to growers. That’s why so many industry officials are excited about the rollout of varietal fact sheets co-created by the Almond Board, UC-ANR, and the Fruit and Nut Center (FNC) at UC Davis.. These factsheets  are housed on a new website that will launch later this year at the FNC center. The first fact sheet debuted is on Yorizane and can be viewed here.

    “The data that is being generated is important and frequently actionable, but to date there has not been a particularly convenient way to access the results from these research projects,” said Julia Stover-Blackburn, director of Fruit and Nut Center. “ABC and UC-ANR do a great job of communicating findings at The Almond Conference and other meetings throughout the year, but we anticipate that making these results findable in the same place will help extend the reach.”

    She said the website will have an overview of various almond-breeding resources but primarily will serve as a repository for the findings of the most recent Regional Variety Trial. A second site is under construction to serve as a repository for almond rootstock trial findings. The hope, Stover-Blackburn explained, is that the sites “will be a resource for both researchers and growers looking to see how various varieties and rootstocks compare in these extensive trials.”

    “These data are valuable for growers making decisions about new plantings and for researchers making decisions about what varieties to include in other projects,” she said.

    The importance of RVTs cannot be overstated. Saa said 14 of the 15 most popular almond varieties in California are the product of trials. Initiation is already under way for the next RVT, which Saa expects to plant on the ground late in 2022 or early in 2023 and continue for a decade or more. He said the next trial likely will include many novelties in comparison to the current regional trial and that ABC is already working to identify the ad hoc research team.

    “Having third-party data collection about how that variety performs in different regions of the state is very valuable to growers, nurseries and handlers,” Saa said. “We need to know the weaknesses and strengths of varieties. There is no perfect variety. Some growers are looking for different things, like harvest times or kernel characteristics. There is no doubt that we need a diverse supply of almonds varieties.”

    Gordon said RVTs allow horticultural characteristics like yield, bloom overlap and harvest timing to be compared in an unbiased setting.

    “If there are conditions that are conducive to disease development, they can also be a way to compare relative susceptibilities to diseases,” she said. “They also allow growers and PCAs to see new varieties in person before committing.”

    Industry members interested to learn more about ongoing research should stay tuned for a report that will be issued this spring summarizing the RVT data collected in the past four years.

    In addition, industry members are encouraged to check out this session from The Almond Conference 2020 during which Gordon and other experts provide information on the latest varieties and selections under evaluation, in addition to discussing ABC’s overall breeding strategy.

    Finally, in 2020, the Almond Board published a comprehensive breeding report that provides an evaluation of national and international varieties and selections currently under evaluation or available in the market. Those interested in sinking their teeth into this topic are welcome to review this report. —     Almond Board of California

  • New Walnut Variety to Allow Earlier Harvest

    University of California, Davis, researchers have bred a new walnut variety designed to provide growers a way to harvest earlier and boost the harvest efficiency of California’s $1.6 billion walnut industry. The new “UC Wolfskill” walnut has yield, quality and light color similar to Chandler, which is a late-harvesting walnut and the state’s leading variety. UC Wolfskill was bred in 2003 from a cross of Chandler with the Solano walnut. UC Wolfskill combines the color and shell traits of Chandler with the earlier harvest date and kernel fill of Solano.

    “The release of UC Wolfskill means growers can spread out their harvest and still have a really high-quality nut that will fetch top-notch prices and provide similar yields,” said Pat J. Brown, breeder and professor with the UC Davis Department of Plant Sciences.

    Over 99 percent of the nation’s walnuts are grown in California. More than half of the state’s bearing acres are the late-harvest Chandler walnuts. “The California walnut industry needs earlier harvesting walnut varieties to provide efficient use of harvesting, drying and processing equipment,” said breeder Chuck Leslie, with the UC Davis Walnut Improvement Program. “UC Wolfskill can be harvested 12 to 14 days earlier than Chandler and provides consistently light to extra light color.”

    Handlers judge the value of a walnut based on its color and how well it halves while processing. In blind quality evaluations by commercial graders, the UC Wolfskill was often not distinguished from Chandler.

    UC Wolfskill was originally planted and evaluated at UC Davis, and field trials with growers began in 2011.

    “The commitment of our walnut growers, as collaborators, is the foundation that makes this release possible. The Board is extremely grateful for the long-term partnership of our growers and the UC, in finding innovative solutions that help us solve for critical needs,” said Michelle Connelly, executive director of the California Walnut Board.

    The California Walnut Board funded the research. UC Wolfskill is currently available to California nurseries for propagation in California and sales to growers throughout the United States. Nurseries interested in propagating and selling this cultivar may obtain a license from UC Davis InnovationAccess. – By Amy Quinton, UC Davis Food & Ag

    “Editor’s Note: Photos Provided by Janine Hasey, UCCE Farm Advisor Emeritus”

  • Almond Ganoderma Butt Rot Spore Survey

    Ganoderma butt rot has been an increasing problem in the almond industry. The disease has been responsible for trees falling over all throughout the Central Valley. Ganoderma butt rot is caused by wood decay fungi that can spread via spores in the air. In order to better focus our management efforts, researchers must conduct a spore survey that will help us determine the times and locations that are at greatest risk of infection and spread by spores.

    The survey will include collecting air samples at almond orchards once a month for 2 years, so it will require long-term cooperation, but will be non-invasive and will not interfere with management practices. Any almond growers interested in volunteering their orchards (any age orchard works) for the research conducted by UC Davis plant pathologists, please contact Daisy Hernandez.

    Thank you all for your time and help.

    Contact:
    Daisy Hernandez, PhD, Student
    David Rizzo Lab,
    UC Davis
    Email: dahe@ucdavis.edu