California Ag Network

Category: Citrus Industry

  • Tips to Save Avocado from Root Rot

    Root rot is a term referring to any disease where the pathogen damage and deteriorate the plant’s root system. Root rot can occur on most woody and herbaceous plants. Root rot is caused by many soil-borne fungi. Most fungi causing root rot to prefer wet soil conditions. Some of them produce spores (microscopic biological particles that allow fungi to be reproduced) that can survive for a long time in soil or plants debris.

    Avocado root rot. Credit: California Avocado Commission

    Symptoms

    • Small, pale green, or yellow leaves
    • Wilted leaves
    • Leaves show necrotic or brown tips
    • Spare foliage and rare new growth
    • Branch dieback on top of the tree
    • A decline in fruit production
    • Small fruits

    Cause

    • Excess soil moisture or poor drainage
    • Infested soil with fungi spores

    Management

    Before infection

    • Monitor your tree regularly for disease and disease-promoting conditions
    • Purchase certified disease-free trees
    • Purchase root rot resistant cultivars
    • Inspect new tree before planting (roots and foliage)
    • Good irrigation management (stop irrigation when heavy rainfall)
    • Avoid planting your tree where you suspect there was an infected tree before
    • Plant in well-drained soil (or improve drainage by planting on a soil berm)
    • Prevent soil or water movement from an infested area
    • Apply gypsum (gypsum supplies calcium which suppresses the formation of spores
    • Use fertilizer regularly to promote good growth

    After Infection

    • Reduce irrigation schedule (especially when you forecast rainfall)
    • Add drainage around the tree
    • Dry root system by removing soil from the crown of the root system (Air drying)
    • Reapply gypsum
    • Apply fungicides such as phosphonates can help trees tolerate the disease. To apply the fungicide, follow the label. Fungicide may be sprayed onto bark or foliage, drench into the soil with irrigation water, or injected into the trunk. Remember fungicide can only help control the disease, not eradicate it.

    — By Amir Rezazadeh, University of Florida Extension

    Reference:

    UC IPM Pest Management Guidelines: Avocado
    https://www2.ipm.ucanr.edu/agriculture/avocado/Phytophthora-root-rot/

  • Mechanical Pruning Trial in ‘French’ Prune – Through Year Three

    Work continues at the mechanical pruning trial site in Red Bluff. The trial, funded by the California Prune Board and led by Dr. Rich Rosecrance at Chico State, was initiated in 2019 and aims to identify lower cost pruning alternatives for growers without compromising yield or fruit quality. The study site is an orchard planted in 2011 at a spacing of 15’ x 18’ on Myrobalan seedling rootstock and irrigated with buried drip. This is a vigorous, well managed orchard with a history of producing 4-5 dry ton/acre. The study treatments are:

    1. Fall: Grower standard — ladders and loppers pruning, no topping (i.e. ‘control’).

    2. Spring: Topping and hedging both ways — cutting 5 sides of the canopy, with the tree row and across the tree row, plus topping (i.e. ‘boxed’).

    3. Fall: Topping and hedging both ways — cutting 5 sides of the canopy, with the tree row and across the tree row, plus topping (i.e. ‘boxed’).

    4. Spring: Hedging both sides of the tree row, no cross hedging — cutting 2 sides of the canopy, no topping (i.e. ‘hedged’). 

    5. Fall: Hedging both sides of the tree row, no cross hedging — cutting 2 sides of the canopy, no topping (i.e. ‘hedged’).

    Several measurements are collected annually to assess the effects of the pruning treatments. Highlights of 2021 results and planned 2022 measurements include:

    • –  Canopy volume was measured in May 2021. Trees boxed in spring were significantly smaller than the hand-pruned control. Trees boxed in fall or hedged in fall or spring did not differ significantly from the control.

    • –  A bark canker pathogen survey (Cytospora, Botryosphaeria, etc.) was conducted to establish a baseline of pathogens present in the field. Several canker pathogens were found, and the control treatment had the shortest canker length. A more thorough evaluation of disease presence and severity will be performed in 2022.

    • –  In 2021, a difference in severity of sunburn damage after extreme heat events was observed. The boxed treatments both had significantly less blue prune drop due to sunburn damage than the control or hedged treatments. This was surprising – fruit is typically exposed to higher light environments in the boxed trees. Though there is no definitive cause at the moment, it may be possible that bowing branches in the hedged treatments or reduced water stress in boxed trees due to smaller canopy size may have contributed. We will continue to assess these differences.

    • –  2021 treatment yields ranged between 3.0 and 4.3 dry ton marketable (A+B screens) yield per acre and no significant differences were found among the treatments in 2021 nor in cumulative yields (Table 1). Large fruit (A + B screens) comprised between 92% and 100% of the four-pound sample from all the treatments (Table 1). The spring hedged treatment did have significantly lower percentage of marketable (A+B screen) fruit than the control and fall boxed treatments. 

      — By Becky Wheeler-Dykes (Orchard Researcher, CSU Chico), Dr. Rich Rosecrance (Professor, College of Agriculture, CSU Chico), Luke Milliron (UCCE Farm Advisor Butte, Tehama & Glenn Counties), and Franz Niederholzer (UCCE Farm Advisor, Colusa & Sutter/Yuba Counties)

  • Asian Citrus Psyllids Found in Fresno County

    The California Department of Food and Agriculture’s Plant Pest Diagnostic Center (PPDC) has identified two Asian citrus psyllids (ACP) on a glassy-winged sharpshooter trap from a packinghouse in the Orange Cove area of Fresno County. This has been the first time that the ACP has been detected in Fresno County since November 2019.

    Following confirmation of the ACP detections, agricultural staff from the Citrus Pest and Disease Prevention Division (CPDPD) began conducting a survey and subsequently collected additional suspect ACP adults and nymphs from trees on the packinghouse premises, which were sent to the PPDC for identification.

    All residential properties with host plants within 400 meters of the detections in Fresno County will be treated to prevent ACP population spread. Any growers who are located within 800 meters of the detection site will be notified by the Fresno County Grower Liaison Teri Blaser.

    Following an increase in recent ACP detections across the Central Valley, including in Tulare and Kern counties, growers, packers, haulers and all citrus industry members are encouraged to be extra vigilant in their ACP mitigation steps and adherence to regulatory practices.

    Questions?
    Contact your regional grower liaison for the latest information on detections near you and coordinated or area-wide treatment schedules. Find your grower liaison here.

    Citrus Pest & Disease Prevention Program

  • Citrus Growers Encouraged to Increase Vigilance Following Recent ACP Detections in Central Valley

    Following recent Asian citrus psyllid (ACP) detections in the Central Valley over the last few weeks, growers, packers, haulers and all citrus industry members are encouraged to be extra vigilant in their ACP mitigation steps and adherence to regulatory practices.

    Recently, multiple ACP were detected on traps at a packinghouse in the Woodlake area of Tulare County. Upon confirmation, visual delimitation surveys began the following day. Live adults or nymphs were found and collected at two more adjacent properties, including an abandoned parcel with citrus host plants. CDFA is working closely with the packinghouse to ensure regulatory compliance. Treatment of host plants on residential properties within 400 meters of the detection will be conducted by CDFA once all necessary notifications, emergency proclamations and public meetings have been held. Commercial citrus operations within 800 meters of the detections will be asked to conduct treatments as well.

    Additionally, one ACP was recently detected on a trap at a juice plant in Visalia, and upon completion of the visual delimitation survey of the find site and adjacent properties, there were no additional finds.

    In Kern County, three ACP trap detections have been identified in the last week. One in the city, and two in rural residential locations in Southwest Bakersfield. These are the first ACP detections found in Kern County since November 2021. CDFA teams have already begun delimitation surveys and treatments will be conducted on residential properties with host plants within a 50-meter area around the detections once proper notifications, emergency proclamations and public meetings have been held. There are no commercial operations for several miles around the Kern County detections.

    These detections are a resounding reminder to continue to follow ACP mitigation best practices and regulatory requirements to efficiently suppress ACP populations and prevent the spread of Huanglongbing to the Central Valley.

     

    If you suspect ACP or Huanglongbing in your orchard, please notify the California Department of Food and Agriculture Pest Hotline at 1-800-491-1899. For questions, contact Kern County Grower Liaison Judy Zaninovich at jsleslie@msn.com, Northern Tulare County Grower Liaison Teri Blaser at tblasersci@ocsnet.net or Southern Tulare County Grower Liaison Jessica Leslie at jess.leslie@hotmail.com.

  • Fruit World Reports High Quality, But Lower Volume, For Early Season Central Valley Stone Fruit

    Fruit World, a family-owned, values-driven grower-shipper of organic and conventional fruit, has been harvesting and shipping delicious organic apricots and cherries since mid-April from their Central Valley orchards. “The March freeze tempered early stone fruit production volumes throughout California, especially compared to the banner year we had in 2021,” explained CJ Buxman, Fruit World co-founder. “Fortunately, the fruit that set is looking good, and all our ranches are yielding great product.”

    Severe weather events this spring impacted California’s cherry crops substantially. “We have been extremely fortunate that our organic cherries from the Patterson area were eleven days earlier than last year and had exceptional quality and a larger peak size. We will finish shipping our cherries by the end of next week with Corals, Brooks and Tulares,” said Fruit World Director of Sales, Cindy Richter.

    As a family operation that is focused on quality and sustainability, Fruit World continues to expand their use of cardboard punnet clamshells. “We have found many of the consumers who are seeking premium fruit, especially organic varieties, are also seeking out more sustainable packaging options,” reveals Bianca Kaprielian, Fruit World co-founder and CEO.

    Grower partnerships have been key to Fruit World’s growth and success. “We are fortunate to have formed long-term relationships with several growers who share our values, dedication to farming, and approach to business,” Kaprielian said. “Blossom Hill’s apricots and Masumoto Family Farm’s peaches and nectarines allow us to provide more varieties, higher volumes and longer seasons of top-notch fruit. They are seamless brand extensions, and fully integrated into the Fruit World family.”

    “No farmer works alone. We depend on partners like organisms in the living soil, good neighbors, talented farm workers, to name a few,” said Nikiko Masumoto, fourth-generation farmer and artist. “Fruit World is one of our loyal partners. We get to focus on what we do best in the fields and Fruit World helps us find a home for our fruit. We couldn’t do it without them!”

    Today’s consumers are thoughtful about the environment and sustainability, and appreciate high-quality fruit packed with flavor. Delight them with extraordinary organic cherries, apricots, peaches and nectarines, all grown by family farms, and available from Fruit World.

    For more information or to place an order, call (559) 650-0334, or visit fruitworldco.com to learn more about the Fruit World story.

  • Farmers Cannot Bear the Burden of Record Inflating Costs Alone

    Among some of the top issues impacting the California fresh fruit industry, and all of the state’s agricultural industries for that matter, are record inflating production costs.  This was addressed at the recent annual conference of the California Fresh Fruit Association (CFFA). Watch this brief interview with CFFA President Ian LeMay as he addresses this.
    Please thank this video’s sponsor Suterra for their industry support.

  • UCCE Experts Share the Latest in Olive Disease Management

    UC Cooperative Experts shared their latest research findings in olive disease management at the recent Olive Oil Day held by the Olive Oil Commission of California (OOCC) in Stockton.

    Jim Adaskaveg, Professor in the Department of Plant Pathology at UC Riverside joined the meeting by video to present his work on epidemiology and management of olive knot and the evaluation of new fungicides for control of olive leaf spot and Peacock Spot. Dr. Adaskaveg has been working with the OOCC for years and has during this time identified a number of promising products for the control of olive knot. The objective is to have a number of products with different active ingredients/ modes of action so that pathogens are unlikely to develop resistance.

    Since these products are not registered on olives, an important part of his work now is on the regulatory side, seeing these products through the EPA process called IR-4. Unfortunately, one of the promising fungicides for Peacock Spot, Ziram (active ingredient ziram), was suddenly cancelled on all crops in February 2022.

    There are additional products in process, including Syllit (a.i. dodine); a decision is expected in October of this year. There is also a product that was previously rejected, Topsin-M (a.i. thiophanate-methyl), that is now back in consideration. In all there are five new fungicide registrations expected.

    For control of olive knot, a number of products have proven effective in the research. Some of these are GRAS (generally recognized as safe) food additives and some are antibiotics (kasugamycin and oxytetrcycline). In order to increase efficacy and reduce the danger of resistence, the most promising approach apprears to be a mixture of chemicals with different modes of action. The food additives do not require complex approvals but the antibiotics are in IR-4. There have been multiple setbacks, but a decision is now expected in December this year for kasugamycin and in March of 2023 for oxytetracycline.

    Mohammed Nouri, UCCE Orchard Systems Advisor presented an investigation of decline symptoms of super-high-density oil olives in the San Joaquin Valley. There are multiple causes of tree decline in CA, including Verticillium wilt, Botryosphaeria, Pleurostoma, Eutypa lata and freezing temperatures; accurately diagnosing these in the field can be very difficult. Consult your local UCCE office or mnouri@ucanr.edu for guidance regarding sampling.

    Dr. Nouri also spoke about the ongoing challenge of Neofabraea. This disease particularly affects the Arbosana cultivar, causing leaf and twig lesions. The infection primarily occurs in wounds caused by mechanical harvest damage but can also appear as spotting on fruit. Research has shown some control with a few fungicides that are in IR-4 for Peacock spot as well. A final optimistic result from a survey of anthracnose in CA found that this disease is not found in commercial CA orchards. It is unlikely to become a significant problem because of low humidity, dry summers, resistant cultivars and a tendency to harvest early.

    Find the full research presentation on the epidemiology and management of olive knot and the evaluation of new fungicides for control of olive leaf spot and Peacock Spot here. — By the Olive Oil Commission of California

  • Water Management Strategies for Hedgerow Olive Orchards in California

    After a year’s hiatus, the Olive Oil Commission of California (OOCC) held its annual Olive Oil Day on March 3, 2022, at the Robert Cabral Agricultural Center in Stockton. The purpose of the Olive Oil Day is to update OOCC members and others in the industry about Commission-funded various research projects and other activities. In keeping with the OOCC’s objective of focusing research projects on areas that will improve returns to olive farmers, the majority of the presentations dealt with olive growing and pest management. 

    Among the many informative presentations shared at the meeting, Giulia Marino, UC Cooperative Extension specialist in orchard systems, gave a report on the “Water management strategies for hedgerow olive orchards in California“. This is a 4-year project that will look at how better irrigation can maximize yields, achieve quality objectives and increase resilience to water restrictions.

    One aspect of this work has focused on better understanding the water needs of CA oil olives. All the basic water research on olives in CA was done on table olives so establishing these basic water needs for CA oil olives is essential.

    The project is using two orchards, one in Corning and one in Stockton. The treatments are a control (the grower’s usual irrigation) and three deficit irrigation regimes beginning at pit hardening (80% ET, 25% ET (x2; one will be modified this year). The trees are being extensively monitored: stem water potential, vegetative growth, fruit size and oil yield and quality, and return bloom.

    Work for the future includes measuring ET and crop coefficient, characterizing phenological stages of the olive, adding a 4th plant-based irrigation treatment and starting to develop an outreach program for better water management.

    A field day to learn more about this research project has been scheduled for June 1 in Stockton—save the date!

    Find the full research report here. 

  • Blueberry Industry’s Kasey Cronquist Named NAMA Ag Association Leader of the Year

    Kasey Cronquist, president of the U.S. Highbush Blueberry Council (USHBC), has been named the National Agri-Marketing Association’s (NAMA) Ag Association Leader of the Year for 2022. Cronquist was recognized at an awards ceremony April 7 at the 2022 Agri-Marketing Conference in Kansas City.

    The award, one of NAMA’s highest honors, recognizes outstanding leadership, achievement and excellence among senior executives who have made significant contributions to the agriculture industry in their roles with associations or commodity organizations.

    “With more than 15 years’ experience with government, association, and non-profits, Kasey was named president of the North American Blueberry Council and the U.S. Highbush Blueberry Council in 2019. It was the perfect place and time,” said Jenny Pickett, NAMA CEO. “Long-term, strategic vision is Kasey’s strength. And while the industry was riding high, new challenges demanded a bold, new vision to ensure continued growth.”

    Soon after taking the helm in 2019, Cronquist led the organization through a strategic refresh, followed by development of a new strategic plan, with a refined vision, mission and plan to make blueberries the world’s favorite fruit. Cronquist recognized the importance of fostering greater collaboration among all industry stakeholders and the need to unite to address challenges and opportunities that will take USHBC programs to the next level. The industry’s support of the changes and vision for the future were reflected in the results of the 2021 referendum. Of those who voted, 84% of producers and importers, who also represent 93% of the volume of highbush blueberries grown, were in favor of continuing the program. This represents a 10% increase in producers and importers (and 13% more volume), of those who voted in favor of USHBC in 2016.

    In 2020, USHBC launched a new overarching brand theme of Inspiring Possibilities for the industry, as well as Grab a Boost of Blue as a motivating call-to-action for consumers. Additionally, the USA Blueberriesexport brand was created to raise awareness of the quality and food safety assurance of U.S. grown blueberries. In June 2020, Cronquist initiated “The Business of Blueberries,” an industry podcast currently surpassing 35,000 downloads.

    In his short time with the organization, Cronquist has built a staff of longtime ag experts to execute the organization’s strategic plan; expanded the NABC and USHBC’s programs through voluntary funding; and led the USHBC through pandemic challenges, including labor and supply chain issues.

    “Kasey has made a tremendous impact helping the blueberry industry thrive and leading the USHBC into an exciting and successful future,” said USHBC Chair Shelly Hartmann. “His efforts have impressed blueberry growers, marketers, exporters and industry allies alike, and have become the guiding force in making blueberries the world’s favorite fruit.”

    Cronquist is also the president of the North American Blueberry Council; a member of the United Fresh Governmental Affairs Council and the International Blueberry Organization (IBO); He was previously the CEO and ambassador of the California Cut Flower Commission.

    About the U.S. Highbush Blueberry Council

    Established in 2000, The U.S. Highbush Blueberry Council (USHBC) is a federal agriculture research and promotion program with independent oversight from the United States Department of Agriculture (USDA). USHBC represents blueberry growers and packers in North and South America who market their blueberries in the United States and overseas, and works to promote the growth and well-being of the entire blueberry industry. USHBC was established by blueberry growers and currently has 2,500 growers, packers and importers. USHBC is committed to providing blueberries that are grown, harvested, packed and shipped in clean, safe environments. Learn more at ushbc.blueberry.org.

  • Growers Experience Minor Frost Damage on SO CAL Avocados

    Calls have come in – “What is the browning on the avocado leaves?  Thrips damage? Salt damage?  Dothiorella?” Nope, Frost Damage. From the end of February to the first week of March, Santa Paula had one night of 30 deg F, and 3 nights of 33 and a few nights around 35..  It wasn’t cold cold, but cold enough that there was damage to the avocados there and more so the further east and up toward Ojai.It wasn’t enough to defoliate the trees, although many were under stress from the flowering that is going on and a lot of the leaves were dropping from the flowering stress.  The damage to the leaves is a darkening of the leaf both of the bottom surfaces.  In many cases, the flower panicles got scorched. This is just the start of a big flower push and it looks like there’s a lot of flowers that have not pushed that will be fine.  It could still be a good avocado year.  The coffee really got roasted. — By Ben Faber, UC Cooperative Extension