California Ag Network

Category: Non-Video

  • Does Adjusting Soil pH Control Clubroot of Brassicas?

    Clubroot disease  can be a serious production issue for broccoli, cauliflower, and other brassicas in the Salinas Valley. The disease  is caused by a unique organism (Plasmodiophora brassicae) that is closely related to ciliate protozoans but is classified in its own taxonomic group. It survives over 20 years as resting spores in the soil that are released as the clubbed root tissue decays. At temperatures above 65 °F, the resting spores release zoospores that swim to host plant roots and infect through root hairs. Once inside the plant, the organism grows into a large multinucleate plasmodium (a multinucleate mass of protoplasm) which stimulates changes in the plant hormones, resulting in enlarged root cells and the characteristic clubbing of the roots (See photo Below). Root infections by the clubroot pathogen can occur in both acid and alkaline soils; however, acidic soil conditions favor the development of the root symptoms. In addition to the main brassica crops, Plasmodiophora can infect arugula, radish, mustard cover crops, and weeds such as shepherd’s purse and even some grasses. Plants that develop severe root swellings will exhibit above ground symptoms (See Photo Above) indicative of non-functioning root systems, which includes yellowing, wilting, poor growth and stunting, drying and death of lower leaves, and eventual plant death.

    Clubroot in the Salinas Valley is mostly controlled by maintaining soil pH above 7.2 to 7.3 by liming. The high pH does not kill the pathogen but inhibits the formation of the root clubs. Soils where control of clubroot by liming is achieved are called “responsive” soils. However, soils where liming is less effective are called “unresponsive” soils.

    In 2020 we had calls regarding the incidence of clubroot on brassicas. In each situation the grower/PCA had soil lab results that indicated that the soil pH was greater than 7.2. To investigate this situation, a small study was conducted. At three fields soil was collected from symptomatic and asymptomatic areas of the crop and soil pH was determined using a pH meter at the UCCE or UC Davis Analytical Lab. The results shown in Table 1 indicate that clubroot was more severe in soils with lower soil pH levels. These findings are consistent with what we know about clubroot, that higher pH soils should have less concern with this disease.

    So why did clubroot occur in soils that had  test pH values greater than 7.2? It is important to keep in mind that soils have a great deal of inherent variability. The goal is to determine if the soil pH for a 5 or 10 acre field is ≥7.2. This is typically done by collecting 15 – 20 soil cores from various parts of the field and mixing them together as a composite sample. However, if sample collection by chance missed areas of lower soil pH, the lab results may be skewed to represent areas of the field that had relatively higher pH values. If this is the case, such a sample could have an artificially high pH (greater than 7.2) while some parts of the field may have a lower pH value. One way to have greater confidence in the soil pH is to collect more soil cores in fields where clubroot disease has been noted in the past.

    At present, we have not seen evidence in Monterey County that soils are unresponsive to liming or that the liming treatment is failing to control clubroot, given variability in soil pH and pH testing. In our intensive vegetable production system, soil pH tends to decrease over time through the use of ammonium fertilizers. The loss of calcium, magnesium and potassium from crop removal and leaching can also contribute to lower soil pH on lighter soils. Given the longevity of clubroot resting spores in the soil, it is important to maintain a liming program to assure that soil pHs are above 7.2 to 7.3 to thoroughly suppress clubroot throughout the field. – By Richard Smith, UCCE Vegetable Crops & Weed Science Farm Advisor, and Steve Koike, TriCal Diagnostics

    Table 1. Three evaluations of soil pH in clubroot affected fields

    Typical clubbing of broccoli roots

  • Rhonda Smith “Heroine of the Vineyards” Wraps up Career

    Rhonda Smith, who has been heralded as the “heroine of the vineyards” for her groundbreaking work in helping combat the parade of problems that have plagued Sonoma County grapevines – and alarmed growers, plans to retire July 1.

    During her nearly 34 years as a UC Cooperative Extension viticulture advisor, Smith steadily emerged as Sonoma County’s expert on all things wine grape. Over the decades, her scientific know-how, meticulous research methodology and incredible work ethic advanced wine grape production in Sonoma County. 

    She cultivated working relationships with growers and vineyard managers, setting up field trials and collecting data in vineyards. As the years rolled by, she earned the respect and admiration of grape growers who wonder what they will do without her.

    “Rhonda Smith became a true icon in Sonoma County viticulture for her timely research and her effective way of communicating valuable information to the wine grape industry,” said Santa Rosa grower Bob Dempel.

    Tito and Janet Sasaki, who farm wine grapes in the Sonoma Valley, have benefited from Smith’s dedication to the wine grape industry. 

    “Rhonda Smith is the quiet heroine of the vineyards in Sonoma County. She has been the family physician of Sonoma County vines for more than three decades,” said Tito Sasaki, past president of Sonoma County Farm Bureau.

    Janet Sasaki said, “Rhonda is the hardest working person I know. My friends and I have been working with her since 1989. No vineyard is too small for her to take an interest in the problem. She is very respected by everyone in the wine grape industry.”

    While earning a B.S. in plant science with an emphasis in plant pathology, and an M.S. in horticulture with an emphasis in viticulture, both at UC Davis, Smith was inspired by former UC Davis plant pathologist Mary Ann Sall and Cooperative Extension farm advisors who collaborated on research to combat diseases that were costing farmers money. 

    “My goal has always been to assist the industry in successfully navigating the delicate balance between grape quality and economically acceptable crop yields – the essential combination to prosper as a premium grower of wine grapes,” she said.

    When Smith arrived in Sonoma County in 1986, phylloxera was fast becoming the largest challenge to grape growers. The aphid-like insect feeds on grapevine roots, stunting vine growth and reducing yields. Eventually thousands of acres in the North Coast needed to be replanted. “Growers had no idea how phylloxera-resistant rootstocks would perform,” she said. Over the years, Smith and UC Davis scientists launched 10 trials to inform growers of the suitability of specific rootstocks in sites with heavy, cracking clay, wet soil conditions and high nematode populations.

    Introduced insect pests – particularly vine mealybug – have been a challenge for growers, who must control them and take steps to prevent transporting the pest to other vineyards. Smith and now-emeritus UC IPM advisor Lucia Varela conducted trials to evaluate the survival of vine mealybug in unfermented winery waste. 

    “We learned that not only could the insects survive the press, but they could walk off uncovered piles of stems,” Smith said. Their research changed how wineries and growers handle fresh winery waste. 

    Smith also collaborated with other UCCE specialists, UC faculty and USDA researchers to investigate the cause of physiological disorders such as berry shrivel, Syrah disorder and pinot leaf curl, the latter causing severely stunted shoots, and partial shoot dieback in different cultivars of Pinot. 

    “Many growers believed the abnormal growth was due to fungal infections,” she said, “but we were able to associate pinot leaf curl to a temporary nitrogen-related disorder, which meant that applying a fungicide would not prevent the problem.”  

    “It’s been fun and rewarding to be part of the Sonoma County wine industry for so many years,” Smith said.— By Tim Tesconi & Pam Kan-Rice

     Read Tim Tesconi’s full story in the July edition of Sonoma-Marin Farm News: https://sonomafb.org/farm-news-archives. 

  • Allied Grape Growers’ Emilio Miranda Retires After 44-Year Career

    Emilio Miranda, viticulturist and grower relations representative for Allied Grape Growers (AGG), retired today after four decades in the wine industry.

    Miranda started with AGG in 2004 after working for Constellation Brands from 1997 to 2004 and Paul Masson Vineyards from 1977 to 1997. For AGG members, he provided support, kept them informed about effective viticultural practices and handled harvest scheduling in the Central Valley.

    Throughout his career, Miranda served on numerous industry boards and committees, including the California Winegrape Inspection Advisory Board, California Sustainable Winegrowing Alliance, California Association of Winegrape Growers, Central California Winegrowers (now San Joaquin Valley Winegrowers Association), American Vineyard Foundation, National Grape & Wine Initiative (now National Grape Research Alliance) and Fresno State Vineyard Evaluation Team. He attended Fresno State from 1973 to 1978 majoring in plant science.

    “I have experienced and appreciated the wine industry from numerous job positions, including vineyard supervisor, cellar supervisor, harvest manager, viticulturist and fieldman. Above all, my most cherished time of year was harvest and bringing in the crop,” Miranda said. “Allied’s strength is helping to keep grape growers economically sustainable, and I was proud to be a part of a successful and hard-working team for the past 16 years.”

    AGG President Jeff Bitter said, “Emilio’s wealth of knowledge accumulated over 44 years in this ever-changing business has been invaluable to AGG. He brought great and diverse perspective to AGG that will be greatly missed, as all of his prior experience was on the winery side of the business. As our viticulturist, he served our growers well. More importantly, he was a friend to all of us.”

  • CA Winegrape Growers Expected to Suffer $437 Million in Lost Sales

    California wine grape growers could suffer at least $437 million in lost sales from this year’s grape harvest due to COVID-19 related economic disruptions. According to an analysis by Jon Moramarco, managing partner of bw166 and editor of the Gomberg-Fredrikson Report, increased sales of wine at off-premise retailers will not offset lost wine sales via on-premise channels and direct from wineries to consumers through wine clubs and tasting rooms. Off-premise includes supermarkets, liquor stores, club stores and wineries; on-premise includes restaurants, hotels and stadiums.

    The volume of California wine sales over the 12 months from March 2020 to February 2021 is expected to decline by 9.21 million cases from the same 12-month period in the prior year. This translates into $437 million less sales revenue for growers.

    Moramarco notes in his analysis that lost sales revenue due to COVID-19 would come on top of the $395 million in reduced sales revenue expected to occur as a result of excess wine inventory following the large winegrape crop in 2018 and slowing consumer demand for wine. Growers’ losses from March 2020 to February 2021 could total $832 million.

    “Moramarco’s analysis makes clear what many California growers already know: growers will experience significant economic hardship following this year’s grape harvest,” California Association of Winegrape Growers (CAWG) President John Aguirre said. “California growers are accustomed to cyclical markets, but the COVID-19 pandemic threatens to turn a down year into a financial catastrophe for many of them.”

    Mike Testa, Santa Barbara Wine Grower & CAWG Chair

    Santa Barbara County grower and CAWG Chair Mike Testa said, “I’ve never seen so much uncertainty in the marketplace. Growers are struggling to find a home for their fruit, vineyard acres are being pulled out and our winery customers are experiencing extraordinary challenges. For many growers, getting paid this year is no sure thing. It is essential that the U.S. Department of Agriculture recognizes the harm COVID-19 has caused our markets, and winegrape growers need to be included in the next round of financial assistance for agricultural producers.”

  • Pierce’s Disease/Glassy-Winged Sharpshooter Continuation Referendum Passes

    The Pierce’s Disease & Glassy-Winged Sharpshooter (PD/GWSS) Referendum, conducted this spring, passed with 78 percent approval of California winegrape growers. All winegrape producer entities that paid the assessment on grapes crushed in 2019 received ballots and 49 percent cast ballots. Assessment funds are used for research, outreach, and related activities on PD, GWSS, and other designated pests and diseases of winegrapes.

    “It is heartening to know that California’s winegrape growers continue to see value in the joint effort that we’ve built together with the assessment,” said CDFA Secretary Karen Ross. “Our growers know and understand the importance of research, and – just as importantly – they recognize the value of their ongoing investment in this exemplary partnership between industry and government.”

    The Board advises the CDFA on the use of winegrape assessment funds and has invested over $47 million since 2001 on research and outreach. The Board sets the annual assessment rate, with a maximum of $3.00 per $1,000 of value, at its summer meeting. The annual assessment rate has averaged $1.39 per $1,000 of value and was $1.00 for the 2019 harvest.

    “In these trying times, we appreciate the support of the industry in passing this referendum,” said Domonic Rossini, PD/GWSS Board chair. “The PD/GWSS Board is always focused on growers’ best interests and ensuring our industry has the best research at its back to protect California vineyards from pests and diseases.”

    The PD/GWSS Referendum is conducted every five years by law, and will take place again in 2025. Through the renewal of the assessment, growers’ continued commitment to the industry and government partnership led by the statewide Pierce’s Disease Control Program leverages funding for essential activities, including:

    • Research
    • Maintaining and monitoring GWSS traps
    • Conducting nursery stock shipment inspections
    • Overseeing nursery stock treatments
    • Controlling GWSS using area-wide management programs
    • Operating a biological control program to suppress GWSS populations

  • New Study Links Dietary Flavonols in Grapes with Reduced Risk of Alzheimer Dementia

    A new study, published in the scientific journal Neurology found that a higher intake of plant compounds known as flavonols, is associated with a 48% decreased risk of developing Alzheimer dementia.

    Flavonols are a type of bioactive compound found in grapes, as well as other fruits and vegetables. Flavonols are known for promoting beneficial antioxidant and anti-inflammatory activities. Grapes of all colors – red, green, and black – are a natural source of flavonols, including kaempferol, myricetin, quercetin, and isorhamnetin. In this study, the benefit observed was most strongly associated with kaempferol, myricetin and isorhamnetin; quercetin was not associated with Alzheimer dementia, although it has been linked to numerous other health benefits.

    Other research has linked the consumption of grapes to brain health: in a clinical study conducted at UCLA, researchers found that eating grapes helped protect against metabolic decline in Alzheimer-related areas of the brain.

    “The new findings linking higher intake of flavonols to a reduced risk of Alzheimer dementia is very exciting and supports the previous positive findings of the beneficial impact grape consumption can have on brain health,” said Kathleen Nave, president of the California Table Grape Commission. “Importantly,” Nave said, “research indicates that just 2 1/4 cups of grapes a day is all it takes to make a positive difference. With more clinical research in this critically important area of human health underway we look forward to having more positive news to share.” 

  • PMA Launches the Essentials of Produce Safety — Online Professional Training Program

    The Produce Marketing Association (PMA) has announced the launch of its eLearning certificate course Essentials of Produce Safety, an entirely online, affordable and in-depth program covering the key challenges and best practices in produce safety. The course is the first certificate program in PMA’s new educational platform offering, FreshEd Academy. The course was developed in partnership with Intertek Alchemy, the industry leader in produce safety eLearning solutions.

    “FreshEd Academy is our commitment to delivering thought leadership to the produce and floral industries, while providing member partners with innovative, yet affordable, educational solutions” said Gina Jones, VP of Insights and Analytics at PMA. “Essentials of Produce Safety is the first of a number of courses and broader initiatives we are launching that pick up where today’s traditional training programs end.”

    Taught by produce safety experts with real life understanding of the challenges and risks, Essentials of Produce Safety is available to individual learners and employee groups alike, with all enrollees benefitting from:

    • Enhanced produce safety proficiency
    • Improved communication across the organization and supply chain
    • Immediate application of learnings to the work environment

    “It is critically important for produce safety supervisors and managers to have an opportunity to receive education on why they are doing what they do, and to gain insights into how to do it even better,” says course author, instructor and former PMA Chief Science & Technology Officer, Dr. Robert Whitaker. “Essentials of Produce Safety is designed to provide that educational experience; converting staid food safety training into an educational opportunity that cultivates industry leading food safety professionals.”

    Essentials of Produce Safety is delivered entirely online via a device responsive learning management system that enables learners to complete the course anywhere, on any device — desktop, tablet or mobile. The course consists of seven learning modules, a review module, and a certificate exam.

    Essentials of Produce Safety instructor Afreen Malik, Director of Technical Services at International Food Safety adds “understanding the science based fundamental principles of produce safety can help lead to a safer produce supply chain globally. Essentials of Produce Safety helps us to do just that.”

    For more information, visit: https://freshed.academy.

  • US Sweet Cherry Production Down 6 Percent (California Increases)

    United States sweet cherry total production for 2020 is forecast at 334,000 tons, down 6 percent from 2019. In California, growers reported sufficient chill, despite an unusually warm winter. Cool weather in March extended the fruit growing season, which led to increased expected yields compared with the previous season. In Oregon and Washington, severe cold snaps in February and mid-March had varying impacts across the region. The later blooming varieties were well behind the rest of the crop, leading to lower expected yields, especially in Washington. 

    Tart Cherry Production Down 25 Percent

    United States tart cherry total production for 2020 is forecast at 197 million pounds, down 25 percent from the 2019 production. In Michigan, the largest tart cherry producing State, an early-May frost damaged the crop throughout the State and most significantly in southwestern Michigan. In Wisconsin, growers reported some crop damage due to heavy winds and frost during blossom. In Washington, growers expressed some concern due to freezing temperatures.

     

  • COMMISSION PROMOTES JUNE CALIFORNIA AVOCADO MONTH

    Summer 2020 marks the ninth year the California Avocado Commission (CAC) has celebrated California Avocado Month, showcasing the availability and versatility of the premium fruit during peak harvest in June. This year, with extended safer-at-home orders in states with the majority of California avocado distribution, the Commission placed renewed emphasis on recipes consumers can prepare at home. “Consumers are continuing to do more cooking at home and they are seeking recipes both for simple comfort foods and for ideas that break the boredom,” noted Jan DeLyser, CAC’s vice president marketing. “During California Avocado Month CAC is promoting recipes on both ends of the spectrum.”

    The Commission partnered with Chef Jordan Kahn of Vespertine in Culver City (who was named “best new chef” in 2017 by Food & Wine Magazine) to create a variety of California avocado-centric recipe concepts. When the in-person California Avocado Month media preview event was cancelled in May, the Commission quickly pivoted and delivered Chef Kahn’s culinary creations and branded California avocado items to the homes of key Los Angeles media and influencers. These personalized deliveries were designed to generate excitement for peak California avocado season and inspire the influencers to share their love for their home-state fruit on their social channels.

    To meet consumers’ penchant for healthy and creative California avocado recipes they can easily prepare at home, the Commission partnered with four award-winning chefs who developed recipes they felt would become the next hottest trend in avocados — in other words, the “next avocado toast.”

    The Commission also partnered with 11 influential California Avocado Blogger Advocates. Throughout the month of June these advocates are publishing unique recipes, blogs posts and photography on their social channels while highlighting techniques that will help consumers prepare fresh California avocado snacks and meals at home.

    CAC’s “Living Well” Brand Advocates will showcase the nutritious benefits of the fruit with recipes consumers can enjoy throughout the day. Registered dietitian nutritionist (RDN) Elizabeth Shaw is sharing California avocado recipes suited for any summer occasion — from backyard picnics to holiday celebrations — on her blog, social channels and ABC’s San Diego Connect. Culinary influencer Patty Mastracco will be a guest on Sacramento’s KTXL FOX40. During the two-part live television segment she will feature grilled California avocados as a great addition to classic summer recipes for the American summer holidays and beyond. RDN Manuel Villacorta crafted a recipe focused on a top health issue facing men today: hearth health. His California Avocado Steak Sandwich Recipe provides consumers with a grilled summer alternative that can be served as a sandwich or salad.

    Rounding out the California Avocado Month promotions are “The best avocados have California in them” advertising campaign, consumer emails, California Avocado Month posts on the Commission’s social media platforms and promotional videos. These assets will appear on streaming video, digital and social channels to reach consumers who continue to shelter at home and encourage them to seek out their favorite fruit during the peak of California avocado season.

  • CA Prune Board Authorized to Continue for Another Five Years

    Following a successful public hearing, the California Prune Board (CPB) has been authorized by the California Department of Food and Agriculture (CDFA) to continue for another five years through July 31, 2025 – without the need for an industry referendum. At the hearing, prune growers and processors voiced unanimous support for the CPB, along with sharing numerous examples of the board’s favorable results on behalf of the California Prune industry.

    “The CPB continuation is a major win for California Prune growers, processors and handlers,” said Joe Turkovich, California Prune grower and Chairman of the California Prune Board. “The board’s work is vitally important to the success of the prune industry. It has carefully considered strategic priorities that will continue building industry momentum for the next five years and beyond.”

    California Prune Board: Delivering Leadership and Value
    The hearing comes amid industry headwinds facing California agriculture in general, such as rising labor costs and increasing regulations. Additionally, the California Prune industry has specific challenges including a global market driven by low prices and smaller, inferior quality imported fruit.

    “We have navigated through many challenges and are currently addressing others – such as tariffs that create major impediments to growing markets – all while knowing there are many challenges around the corner. Yet, we believe in the values the industry has together set forth,” said Donn Zea, Executive Director of the California Prune Board. “Our board and committee members are dedicated to the industry’s success and bring integrity and unique perspective to each discussion. The CPB team around the world is both humbled and proud to join them for the hard work that lies ahead.”

    Together, we have achieved much as a board and as an industry, added Zea, citing examples such as:

    • Securing more than $50 million in United States Department of Agriculture (USDA)/Agricultural Marketing Service (AMS) purchases of California Prunes during a three-year timeframe (2017 – 2019) for school nutrition programs and food banks
    • Dedicating more than $1.25 million during the past three years to nutrition research to scientifically validate the remarkable health benefits of California Prunes for gut and bone health, as well as
      overall wellness
    • Investing more than $1.3 million during the past three years to crop production research, including important findings and advancements related to mechanical pruning, rootstock anchorage, new varietal development, and pest and disease control
    • Securing $11.4 million in federal grant funding for export programs, while partnering with the Foreign Agricultural Service (FAS) each year to defend, grow and develop international markets
    • Being recognized by FAS as “highly effective” in CPB proposal quality, strategic execution, and financial and regulatory compliance
    • Developing an extensively researched, thoroughly vetted new California Prunes brand to unite the global industry under a cohesive banner to communicate the one-of-a-kind premium nature of California Prunes

    California Prune Board: Building on the Momentum, Advancing Priorities
    With input from numerous industry members and under the leadership of the CPB executive committee, the board has outlined key priority areas to rally the industry’s efforts. Focus areas include:

    • Nutrition research
    • Trade policy and market support
    • Industry unification
    • Production research
    • Global visibility expansion for California Prunes

    “We have listened intently to California Prune growers and handlers to identify these priority areas that will inform our focus, guide our decisions, and ultimately, make a positive and sustained difference for the global California Prune industry,” said Zea.

    California is the world’s largest producer of prunes providing about 40 percent of the world’s supply and more than 90% of the U.S. supply. Today, there are more than 40,000 bearing acres of California Prune orchards concentrated in the Sacramento and San Joaquin Valleys.

    ABOUT THE CALIFORNIA PRUNE BOARD
    Created in 1952, The California Prune Board aims to amplify the premium positioning and top-of-mind awareness of California Prunes through advertising, public relations, promotion, nutrition research, crop management and sustainability research, and issues management. The California Prune Board represents approximately 800 prune growers and 28 prune, juice, and ingredient handlers under the authority of the California Secretary of Food and Agriculture.