Posts Tagged: Agriculture

ANR hires expertise in urban pests, plants and small farms

From Siskiyou County through Riverside County, University of California Agriculture and Natural Resources has hired UC Cooperative Extension experts to help Californians address challenging issues.

The eight recently hired UC Cooperative Extension specialists, advisors and coordinators bring expertise in urban pest management, healthy families, regenerative agriculture, plant science, small farms and food safety to their communities.

Since 1914, UC Cooperative Extension researchers have been working directly with community members to improve their lives and livelihoods.

To see a list of UC Cooperative Extension experts who have joined in the past few months, visit https://ucanr.edu/About/DirectorySearch/Recent_Hires. The most recently hired scientists are introduced below.

Lee brings expertise in urban pest behavior to Capitol Corridor IPM role 

Sang-Bin Lee joined UC ANR as the urban integrated pest management advisor for the Capitol Corridor – comprising Sacramento, Yolo and Solano counties – to help communities manage urban pests such as cockroaches, termites and ants. 

“My high-level hope is to improve public health and the well-being of people in the Capitol Corridor region by implementing and improving the IPM program,” Lee said.

A native of South Korea, Lee earned his bachelor's in biology from Pusan National University. After working in the food manufacturing sector (which included a stint in Brazil, where he learned basic Portuguese), Lee decided to pursue his passion for studying animal behaviors. During his master's program in ecology at Pusan National University, Lee investigated behavioral changes in zebrafish after pathogen infection.

“My goal was to detect fish with symptoms much earlier than conventional methods to prevent the spread of pathogens in fish farms,” he said.

Intrigued by research on social insects, Lee went on to earn a Ph.D. in entomology from the University of Florida, where he studied the social behaviors of termites. Lee has published 34 peer-reviewed articles in professional journals and has received several awards from Entomological Society of America and other professional societies.

He said that he finds urban pest management to be a fascinating discipline – and a very rewarding endeavor – in the field of entomology.

“My interests lie in the behavior of urban pests, and studying their behavior often provides a great opportunity to improve control measures,” Lee explained. “I have had many opportunities to communicate with people from the pest control industry and homeowners; conversations with these people often inspire me to work harder to help those who need my assistance.”

Lee is based in Fairfield, at the UC Cooperative Extension office in Solano County, and can be reached at sablee@ucanr.edu and (530) 574-9835. He is on X/Twitter @SangBinLee4.

New farm advisor Singh to bring latest research to Siskiyou County 

Jagdeep Singh recently joined UC ANR as the agronomy advisor for Siskiyou County. In this capacity, Singh will primarily focus on crop production in alfalfa, pasture and small grains, as well as pest control and water management.

Originally from Punjab, India's agriculture-rich state, Singh brings a unique perspective to his work.

“My passion lies in directly impacting the lives of farmers who feed the world,” he said. “I'm driven by a constant thirst for knowledge and a commitment to bridging the gap between the most up-to-date research and practical, on-farm solutions. What motivates me is understanding farmers' needs and providing science-based answers to their questions.”

Singh earned a B.S. from Punjab Agricultural University, an M.S. from New Mexico State University, and a Ph.D. from Auburn University.

During his Ph.D. studies, he assessed 70 years of cotton breeding impacts on yield, nutrient relations and root architecture, while also studying cover crops for soil health improvement. His M.S. work focused on guar, evaluating its growth, yield, water extraction patterns and water use efficiency under deficit irrigation, as well as identifying cold-tolerant germplasm for cooler regions of the Southern High Plains.

In his new role at UC ANR, Singh aims to build strong relationships with the local community, certified crop advisers and industry groups, leveraging the well-established extension system.

Singh can be reached by email at fgssingh@ucanr.edu or by calling the UCCE Siskiyou office at (530) 842-2711.

Rosenberg joins UCCE as regenerative agriculture farm advisor 

Sara Rosenberg joined UCCE as a regenerative agriculture farm advisor for Mariposa, Merced and Stanislaus counties.

Her disciplinary focuses are agroecology, sustainable nutrient management, and extension research and methodology. Her past research centers on understanding the implications of diversification (with a focus on crop rotations and cover crops) for California rice systems. For her master's program thesis, she conducted a countywide assessment to learn from rice growers about their experiences with crop rotations and understand barriers to adoption, opportunities, and required resources for successful implementation. This two-year study engaged grower communities to help develop research goals for her Ph.D. studies.

Her doctoral research explored how different summer crop rotations affect multiple sustainability factors including soil health, crop yields, weeds, input use and economics. She also assessed different cover-crop species performance in rice environments and their carbon and nitrogen contributions. 

She earned a master's in international agriculture development and a Ph.D. in horticulture and agronomy from UC Davis.

Prior to working on her Ph.D., Rosenberg was an agriculture advisor in the Peace Corps for more than three years. She worked closely with smallholder farmers in West Africa, implementing conservation agriculture programs and increasing agricultural resilience in both annual crops and tree crops, mainly in the cashew forestry sector. In California, she has worked on farms for more than eight years, including running her own small, diversified farm in Woodland.

She is passionate about community-led development and using participatory research as a powerful tool for developing sustainable solutions. Her aim is to develop collaborative programming that will support a wide range of farm types, including commercial and small-scale, organic and conventional, annual crops, tree and vine crops, and livestock production systems.

She is developing a robust research program aimed at assessing farm sustainability impact across ecological, agronomic, social and economic factors. She will be collaborating with farmers to help overcome barriers to adopting regenerative practices and build their capacity to advance sustainability goals. Rosenberg also will be developing and promoting tested integrative management practices that increase climate resilience and ecosystem sustainability across diverse farming environments. 

Rosenberg is based in Mariposa and can be reached at srosenberg@ucanr.edu and (209) 966-2417 ext. 1417.

Sangha joins UCCE as community water systems advisor 

Laljeet Sangha joined UCCE as a community water systems advisor for Kern, Tulare and Kings counties.

To enhance community resilience, Sangha will lead an integrated extension education and applied research program in water resource management and community development.

He will address critical questions regarding the impacts of environmental stressors, such as chronic long-term droughts, water contamination and increased groundwater demand. Additionally, he will assist in water system consolidations and help communities meet regulatory goals such as those set by the Sustainable Groundwater Management Act (SGMA) and the Irrigated Lands Regulatory Program (ILRP).

Originally from Punjab, India, Sangha earned his undergraduate degree in agricultural engineering from Punjab Agricultural University. He received his M.S. in biosystems engineering from Auburn University and his Ph.D. in biological systems engineering at Virginia Tech.

Sangha's early research focused on the influence of climate variability on ecologically sustainable water withdrawals from streams for irrigation. For his doctoral studies, he evaluated the impact of permit exemptions, climate change and demand growth on water supply. Additionally, he developed methods to quantify unreported water use for crop irrigation.

Sangha also has collaborated on projects in the Colorado River Basin, which explore why the Colorado River no longer reaches the sea. His work includes evaluating the effects of limited water availability on irrigation operations and developing adaptive options for farming communities in the basin.

Sangha is based in Bakersfield and can be reached at lsangha@ucanr.edu.

Beveridge joins ANR's Small Farms team 

Claire Beveridge joined UC ANR as a small farms water-conservation academic coordinator for Fresno, Tulare and Madera counties. She is also part of the statewide UC Sustainable Agriculture Research and Education Program, or SAREP.

As an academic coordinator, Beveridge supports small-scale, diversified and socially disadvantaged farmers in Fresno and surrounding areas in on-farm water conservation through education, technical assistance, outreach and research activities. This encompasses aiding farmers with improved irrigation practices and technologies, groundwater regulation compliance and on-farm groundwater recharge.

She also facilitates small-scale farmer access to state incentives for water and energy efficiency, as well as drought and flood relief programs. Beveridge also helps to inform state water policy on the unique needs of small-scale farms.

She is broadly interested in fostering sustainable water resource management through interdisciplinary and collaborative approaches among communities, decisionmakers and researchers. 

Beveridge holds a Ph.D. in civil and environmental engineering with an emphasis in hydrology from the University of Washington. She conducted postdoctoral research at Florida International University and earned her bachelor's degree in civil and environmental engineering from UC Berkeley. She is a licensed Professional Civil Engineer in California, an inaugural editor of the Community Science Exchange journal and resource hub, and recently completed a USDA International Agriculture Education Fellowship in Uganda.

“I grew up in Madera and am excited to be serving my home region as part of UC ANR,” she said.

Beveridge is based in Fresno and can be reached at cbeveridge@ucanr.edu.

Pourkhalili to promote healthy families and communities 

Azin Pourkhalili joined UCCE as a youth, family and community advisor for Kern, Inyo and Mono counties. 

In her role, she will promote healthy families and communities by designing, delivering and evaluating strategies for encouraging nutrition and physical activity in youth and their families. Additionally, she will provide academic oversight of community education and outreach program staff who work with families and youth, including the UC 4-H Youth Development Program, CalFresh Healthy Living UC Nutrition Education Program, Expanded Food Nutrition Education Program (EFNEP) and Juntos.

Pourkhalili brings over six years of experience in conducting health intervention research programs, including their development, implementation and evaluation. 

Before moving to California, Pourkhalili was a Virginia Cooperative Extension research scientist. She worked on multiple health intervention projects, including nutrition education for older adults through the Elder Nutrition and Food Safety program and the prevention and management of chronic diseases through programs such as the Lifestyle Change Program, Diabetes Prevention Program, Balance Living with Diabetes, and Kick'n Cancer. She also collaborated with the Virginia Department of Health on various projects.

Pourkhalili's academic background encompasses the latest research in nutrition and physical activity education programs, chronic disease prevention programs and health education programs for different age groups. Building on her experience in implementing and evaluating nutrition education programs, her future research aims to address the unique health education needs of diverse communities in California. She plans to continue researching the evaluation and effectiveness of health education programs, such as CalFresh Healthy Living UC, EFNEP and 4-H. 

She holds a Ph.D. in human nutrition, food and exercise, specializing in community and behavioral science, and a graduate certificate in gerontology from Virginia Tech.

Pourkhalili is based in Bakersfield and can be reached at apourkhalili@ucanr.edu.

Atume to provide small farms SGMA technical assistance 

Ngodoo Atume joined UC ANR as a Sustainable Groundwater Management Act small farms technical assistance coordinator in the Sustainable Agriculture Research and Education Program.

She will provide technical information, services, policy analysis and recommendations needed to engage and protect small-scale farmers in the implementation of the Sustainable Groundwater Management Act (SGMA).

Before joining UC ANR, Atume worked as a water policy analyst advocating for the implementation of the Human Right to Water in California. She also worked on the inclusion of underrepresented stakeholders in SGMA, Central Valley Salinity Alternative Long-Term Sustainability (CV-SALTS) and the Irrigated Lands Regulatory Program (ILRP).

Born and raised in Nigeria, Atume earned her bachelor's degree in water resources and environmental engineering at Ahmadu Bello University, where her research focused on the treatment and reuse of wastewater. She has a master's degree in sustainable water management from Tufts University.

Atume is based at the UC ANR office in Davis and can be reached at natume@ucanr.edu.

Fujiyoshi joins Capitol Corridor small farms team 

Phillip Fujiyoshi joined UCCE small farms team in the Capitol Corridor as an extension and research associate. Working with Margaret Lloyd, UCCE small farms advisor, Fujiyoshi supports underserved farmers in Yolo, Sacramento and Solano counties by providing them with financial and agronomic technical assistance and making extension materials available in Spanish.

Born and raised in Santa Maria, Fujiyoshi earned his bachelor's degree in biology at the Massachusetts Institute of Technology. His academic knowledge of Spanish transformed into bilingual proficiency thanks to his life experiences of living with Spanish roommates, participating in a tree-planting brigade in Nicaragua and setting up a Spanish-speaking household with a Nicaraguan partner. The Nicaragua trip also sparked his lasting interest in agriculture, leading him into doctoral studies in agroecology at UC Santa Cruz.

After completing his Ph.D., Fujiyoshi performed molecular assays, contributed to phylogenetic studies, and led a spore-trapping field study in a lab studying grapevine trunk diseases. In addition, he pursued outside interests in agriculture, including winning an individual grant to study cabbage aphid behavior, pursuing informal cover crop trials in a community garden plot, volunteering on the UC Davis Student Farm, and giving agronomic advice to growers at the farmers market.

Fujiyoshi is based in Woodland and can be reached at (530) 666-8143 and pfujiyoshi@ucanr.edu.

Barnes brings hometown knowledge to UCCE in Lake, Mendocino counties

New Cooperative Extension director has worked extensively with Native American communities, youth groups

Growing up in Upper Lake, along the “North Shore” of Clear Lake, Matthew Barnes lived near several of the Lake County region's seven federally recognized tribes. Although he counted several Native Americans among his diverse circle of childhood friends, and was very familiar with those communities, Barnes was nonetheless quite nervous when he was appointed in 2009 as the inaugural executive director of the Boys & Girls Club of the Pomo Nation.

Barnes – a non-Native of European and Filipino descent – vividly remembers the tribal administrator paying him a visit on one of his first days on the job. “He said, ‘Hey, you have two ears and one mouth, so listen twice as much as you speak and you'll be fine,'” Barnes recalled. “And that's definitely stuck with me.”

That approach is continuing to guide Barnes in his new role as University of California Cooperative Extension director for Lake and Mendocino counties. He will guide and support research, outreach and education activities to meet the area's agriculture, natural resources, and youth and community development needs.

Since starting in May, Barnes has been getting a crash course from UCCE advisors and staff on viticulture research, pest management practices, 4-H camps, and a host of other projects and programs – while also meeting with local communities on the region's most pressing challenges.

“What I've been doing – and will continue to do – is just to listen and learn, and when I can add value to a conversation or project, then I'll do that,” Barnes said. “But leadership to me starts with the relationships we build – with our staff and with the community.”

Bringing a range of experiences in youth programs, social services

One area in which Barnes will certainly add value is developing youth and community programs. During his time with Boys & Girls Club of the Pomo Nation, it was one of only three Boys & Girls Clubs established on tribal land in California. In that role, Barnes faced the unique challenge of integrating the Boys & Girls Club curriculum into a community for which it was not originally designed.

By adapting the curriculum to include culturally relevant topics, Barnes transformed the program into a model that eventually aided in the creation of a Native American-focused branch, Boys & Girls Clubs of America Native Services.

“This initiative now serves as a national standard for Boys & Girls Clubs on tribal lands,” Barnes said.

He later became a director of California Tribal TANF (Temporary Assistance for Needy Families), a direct cash assistance and supportive services program for Native American families in 17 counties across the state.

During his decade of TANF work, Barnes launched career development programs, alcohol and other drug counseling programs, and cultural revitalization initiatives. Some of the programs are still running and serving communities to this day.

“The trick is making those programs something that participants can see the value in,” Barnes explained. “And to do that, you go into the communities and talk to people and listen to what they need – instead of you telling them what they need.”

Barnes' experience partnering with Native American communities is just one of the many strengths he will bring to UCCE and UC Agriculture and Natural Resources.

“We're very excited to have Matthew join the UC ANR family,” said Lynn Schmitt-McQuitty, UC ANR's director of County Cooperative Extension. “His personal knowledge of Lake and Mendocino counties and his previous work with Indigenous populations will be a tremendous asset to extending and elevating our work.”

Immediately prior to joining UC ANR, Barnes served as director of Lake County's Upward Bound program, which helps students from three local high schools experience and prepare for higher education.

“Overall, what drives me personally is the opportunity to make an impact on communities, on youth, and on people in general through program development and management,” Barnes said.

Inspiring young people as a mentor

Barnes' passion for youth development – and the impetus for his bachelor's degree in social work from Cal Poly Humboldt – can be traced to his AmeriCorps experience while he was attending Mendocino College. For two years, he worked as a tutor for young people, in Lake County and then in Sonoma County, and saw firsthand the difference educators and mentors can make in their lives.

“You could say I kind of caught the bug – just seeing the light bulbs go on when you're helping a youth of that age,” Barnes said.

From there, Barnes took a position directing teen programs for the Boys and Girls Club of Healdsburg, where he began to fully appreciate the importance of trusted adults simply “being there” for young people as a listening ear for whatever they want to talk about.

Among the many teens Barnes worked with, “Rodrigo” was a middle schooler who was pegged by his school and community as someone who could “slip through the cracks.” Rodrigo was the last to go home at the end of each day, and Barnes would chat with him – answering his questions about life or just talking about a new rap album.

“I realized I was ‘that person' for him – that person outside his house, outside his school,” Barnes said.

Even after Barnes left the Boys and Girls Club, Rodrigo – bound for university – invited him to his high school graduation. Barnes said it is tremendously gratifying to know he had a “small role” in shaping the path for Rodrigo – and countless others.

“Their success is still theirs; it's not necessarily because of me,” Barnes added. “My job is to do what I can in the moment to hopefully plant some seeds that may sprout in the future.”

Settled in Middletown, not far from his hometown, where he and his wife are raising two children, Barnes is now positioned to help nurture a flourishing Lake County and resilient Mendocino County.

“I feel like my past experiences, both in life and my career, have prepared me for this,” Barnes said.

Paper highlights how climate change challenges, transforms agriculture

As the climate continues to change, the risks to farming are only going to increase.

That's the key takeaway from a recent paper published by a team that included UC Merced and UC Agriculture and Natural Resources researchers. The paper dives into what those challenges are, how farmers are working to address them and what should come next.

"Climate Smart Agriculture: Assessing Needs and Perceptions of California's Farmers" was first authored by Samuel Ikendi, academic coordinator, with Tapan Pathak, UC Cooperative Extension climate adaptation in agriculture specialist, as a corresponding author. Both are based at UC Merced. Pathak is also a project director of National Institute of Food and Agriculture-funded project "Multifaceted Pathways to Climate-Smart Agriculture through Participator Program Development and Delivery," which supported this study. The study appeared in the open access journal Frontiers in Sustainable Food Systems.

The needs assessment was designed to understand farmers' perceptions and experiences with climate change exposures; the risk management practices they currently use; and what tools and resources would assist them in making strategic decisions.

Of the farmers surveyed, roughly two-thirds agree climate change is occurring and requires action. Even more said they are interested in learning more about the impacts of climate change on the agricultural industry. Most respondents said they experience greater climate change impacts on their farms today compared with 10 years ago.

Farmers were very concerned with water-related issues, with those in the San Joaquin Valley, Central Coast and Inland Empire areas particularly worried about a reduction in the availability of groundwater. Increased drought severity was a very significant concern among farmers in the Inland Empire, Central Coast and Southern regions. Farmers in the North Coast and Southern regions were concerned about increased damage to crops due to wildfire.

Closely related were temperature-related issues, including crop damage due to extreme heat.

Those who farm vegetables were more concerned about water availability for irrigation, while fruit farmers were more concerned about increased crop/water stress and increased crop damage due to extreme heat.

Many respondents said they are implementing climate adaptation practices including managing water resources, maintaining soil health and making more use of renewable energy sources. They are seeking insurance and government help to pay for these adaptations and increase their agricultural resilience, the researchers wrote.

The farmers expressed interest in learning more about measures they might take to mitigate climate change. But they cited significant barriers to this work, including government regulations, high implementation cost, labor access/cost, access to water and the availability of money to pay for it.

"Climate change is significantly altering California's highly diverse agricultural landscape, posing challenges such as increased water stress, heat stress, and shifting growing seasons," Pathak said. "Climate-smart agriculture practices can alleviate some of those stresses."

But, he said, research and UC Cooperative Extension efforts only have value if they lead to enhanced climate-informed decision-making at the local level.

"Assessing their level of knowledge, perception and needs will help in tailoring research and extension activities that are most relevant to farmers on the ground," Pathak said. "Results from this study could also provide important policy insights on financial incentives and technical assistance."

 

New project aims to use farm waste to fuel bioeconomy

UC ANR to help create database, support technology for sustainable bioproducts and biofuels

In California's Northern San Joaquin Valley, crop leftovers such as almond shells, fruit peels and orchard trimmings can potentially be converted into sustainable bioproducts and biofuels – with the right technology. The philanthropy Schmidt Sciences' Virtual Institute on Feedstocks of the Future, which supports replacing fossil feedstocks with renewable biomass sources, has awarded new funding to a group investigating how to make better use of the diverse agricultural waste in the region.

“This is an important project for California as it quantifies the diverse ‘ingredients' in the North San Joaquin Valley available to fuel the emerging biomanufacturing industry in the state,” said Gabe Youtsey, chief innovation officer for the University of California Agriculture and Natural Resources. “This foundational work will kickstart a completely new innovation bioeconomy in the Central Valley that will create new high-paying jobs for our communities and support a resilient food and agriculture industry through circular biomanufacturing.”

Circular biomanufacturing is a process that uses waste streams as raw materials to create new products.

“Circular means taking waste streams from agriculture such as almond shells or grape pomace, forest waste or food processing waste and using that material as the ‘feedstock' in a fermentation tank to create new bioproducts,” Youtsey explained.

The group, “Building the Circular Bioeconomy in the North San Joaquin Valley” or BioCircular Valley, is co-led by the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab), UC Berkeley, and BEAM Circular, with partners at UC Merced, UC Agriculture and Natural Resources, the Almond Board of California and USDA Agricultural Research Station in Albany.

“California has this incredible diversity of materials, but they aren't well understood – and this makes it difficult to know how to extract the most value out of them,” said Corinne Scown, a senior scientist at Berkeley Lab and UC Berkeley and one of the project leads. “We want to characterize them and make that information available so companies can more easily figure out which feedstock is a good match for them, and then use that agricultural residue to make everything from bio-based polymers and chemicals to sustainable materials and aviation fuels.”

One of the group's goals is to build a publicly accessible database and user-friendly map full of information about different feedstocks, the raw plant materials and biomass that can be broken down and used to make bioproducts. That includes where feedstocks are located, when they are available, how they are currently disposed of, how they perform in different bioreactors, how much sugar or lignin they contain, whether they can be processed with other feedstocks, their greenhouse gas footprint, the potential cost, and much more.

UC ANR's role is to collect data on available feedstocks from forest, agricultural and food processing byproducts, as well as municipal waste streams through sampling and observation.

“We will do this through the extensive knowledge and relationships we have with the California agriculture industry in the North San Joaquin Valley,” Youtsey said. “UC ANR will also support industry outreach as new ‘conversion' technologies are developed, to pilot them with California growers and processors.”

The project will also test ways to improve the flexibility of the conversion process, which breaks down feedstocks to prepare them to make bioproducts. Researchers will apply artificial intelligence to their lab-generated data to improve predictions of how feedstocks can be processed most efficiently or blended together. Being able to use the same technique on different (or mixed) kinds of plant matter would open up ways for companies to make bioproducts more easily.

“Our region has a fantastic combination of diverse and large-scale agricultural activities alongside manufacturing expertise, making this a great place to scale up bioeconomy innovation,” said Karen Warner, CEO of BEAM Circular. “This project will allow us to reduce barriers to using our region's abundant waste streams in more sustainable and valuable ways, so that we can create the products that people need with renewable inputs that are better for the planet.”

The project builds on ongoing efforts to establish biomanufacturing capabilities in the northern San Joaquin Valley, which includes San Joaquin, Stanislaus and Merced counties. Providing better data on how to convert the valley's millions of tons of agricultural waste into valuable products may spur biomanufacturing companies to build facilities nearby, minimizing how far the raw materials have to be moved and generating new jobs.

“This project is designed to benefit a region that has massive potential, but so far has been economically left behind, and to develop a new industry that can provide improvements in air quality, water quality and greenhouse gas emissions as well as significant opportunities in economic equity and the creation of new jobs,” said Blake Simmons, director of Berkeley Lab's Biological Systems and Engineering Division and the BioCircular Valley project lead.

“This kind of research started as basic science, and now we're bringing information and solutions to people who can use them. And the knowledge generated through this project will advance not only the ability of the NSJV to make use of its own regionally available future feedstocks, but will also accelerate the understanding of feedstocks relevant across California and across the U.S.”

The new funds for the project come from the Virtual Institute on Feedstocks of the Future, a partnership between Schmidt Sciences and the Foundation for Food & Agriculture that supports collaboration on research to transform biomass into alternative feedstocks for biomanufacturing. The award is one of five announced today, which total $47.3 million over five years. It is expected that the five teams will collaborate to share best practices and knowledge to boost the bioeconomy at the national level.

“We are grateful for Schmidt's generous support that will help deploy advanced technologies on the ground,” said Alicia Chang, interim president of Berkeley Lab Foundation. “The foundational research and expertise developed through work for the Department of Energy sets the stage for this team to apply their capabilities to bring jobs and lift the community and the economy in the Northern San Joaquin Valley.”

Almond crop yields threatened by disease new to California

Detection of fungus causing red leaf blotch spurs call for grower vigilance

Symptoms of red leaf blotch (RLB), a plant disease caused by the fungus Polystigma amygdalinum, have been observed for the first time in California across the Northern San Joaquin Valley.

Molecular DNA testing by the laboratory of Florent Trouillas, University of California Cooperative Extension fruit and nut crop pathology specialist, has detected P. amygdalinum. Pest identification was confirmed by the California Department of Food and Agriculture and U.S. Department of Agriculture.

The disease, named for the characteristic orange-to-dark red blotches that appear on infected leaves, is typically nonlethal for trees but has been a long-standing problem for almond-growing regions across the Mediterranean. Causing trees to lose their leaves prematurely, the fungal pathogen can significantly diminish crop yields in the current year and the next.

“It is one of the most severe diseases of almonds for Spain and the Middle East,” said Trouillas, an associate professor in the UC Davis Department of Plant Pathology. He recently co-authored an explanatory article on the UCCE San Joaquin Valley Trees and Vines blog.

With symptomatic trees seen in multiple orchards across Madera, Merced, San Joaquin and Stanislaus counties, Trouillas said RLB is already “somewhat widespread.”

“From the first observations so far, it seems like it affects some of the most-planted cultivars, like Nonpareil and Monterey,” he added. “We've observed it in a diversity of cultivars already.”

UC Cooperative Extension specialist urges taking preventive measures

According to Trouillas, RLB caused by P. amygdalinum is “highly specific” to almond trees, and generally only affects their leaves. Infection typically happens at petal fall, when small leaflets are first emerging and most susceptible to disease. After the pathogen's latent period of about 35 to 40 days, the first symptoms appear – small, pale-yellow spots on both sides of the leaves.

Those blotches become yellow-orange and then reddish-brown in the advanced stages of the disease during June and July. Now, with RLB symptoms becoming more prominent, Trouillas and UC Cooperative Extension advisors across the Central Valley have seen an uptick in calls.

“PCAs [pest control advisers] have been confused because they've never seen anything like this,” said Trouillas, noting that the yellow-orange-red blotches are symptoms unique to RLB and cannot be confused with other known almond diseases.

Applying fungicides after RLB symptoms appear is ineffective, Trouillas said. The best thing growers can do at this point is to report symptomatic trees to researchers so they can track the prevalence and distribution of the disease.

Growers who see signs of this new disease in their orchard should contact their local UC Cooperative Extension farm advisor.

Preventive measures are the best way to manage RLB, Trouillas said. He urges concerned growers to think ahead to next winter/spring and plan for fungicide applications at petal fall and – if rains persist – also at two weeks and five weeks after petal fall. Fortunately, those are the same three key timings for managing other diseases, like shot hole and almond anthracnose.

“Because RLB is something that is introduced and potentially aggressive, it will be important for growers to keep that in mind next year and be on schedule for next year's spraying program,” Trouillas said.

Additional information on RLB can be found at https://www.sjvtandv.com/blog/first-detection-of-red-leaf-blotch-a-new-disease-of-almond-in-california.

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