California Fruit and Vegetable

Tag: HLB

  • NIFA Invests $21.7M in Emergency Citrus Disease Research and Extension

    USDA-NIFA’s Emergency Citrus Disease Research & Extension (ECDRE) program brings the nation’s top scientists together with citrus industry representatives to find scientifically sound solutions that combat and prevent citrus greening (HLB)​ at the farm-level. For the first time in the program’s history, NIFA is supporting an HLB-focused Coordination Network (CN) Project led by an interdisciplinary team of scientists representing all three major citrus producing states. This CN project will benefit the US citrus by providing a much-needed synthesis of existing HLB research in an easily accessible online database as well as developing region specific decision support tools for citrus industry stakeholders, the HLB-research community, and research organization administrators.

    Among the funded research includes virus-induced gene silencing at UC Davis using insect specific viruses to manipulate psyllid as a strategy to control HLB in citrus. Read about all the funded research projects HERE.

  • New Commercial HLB Detection Response Guide

    To ensure California citrus growers are well prepared in the event of a potential commercial grove detection of Huanglongbing (HLB), the deadly citrus plant disease that can be spread by the Asian citrus psyllid (ACP), the Citrus Pest and Disease Prevention Program (CPDPP) has developed a response guide for growers to utilize and educate themselves on the California Department of Food and Agriculture’s (CDFA) action plan.

    The Response Guide for a Confirmed HLB Positive Detection in a Commercial Grove details the steps taken by CDFA and actions required of the property or grove owner, as outlined in CDFA’s Action Plan.

    The actions in the response guide represent the most effective tools known to the citrus industry at this time and are meant to protect California’s citrus groves and support CDFA’s current required regulatory response. While, as of today, there have been no positive detections of HLB in a commercial citrus grove, the CPDPP recognizes the importance of proper preparation.

    In addition to the requirements outlined in the guide, growers are encouraged to use as many methods as feasible for their operation in order to limit the spread of the ACP and HLB.

    To read or download the response guide, please click HERE. If you have any questions or would like to order physical copies of this response guide, please visit our Resources page. — By the California Citrus Pest & Disease Prevention Program

  • Promising Advancements in Biocontrol Treatment that Slows Citrus Greening

    Citrus growers may have a new tool to help them slow the presence of citrus greening in already diseased trees. While there is no cure for Huanglongbing (HLB), researchers at the University of Florida Institute of Food and Agricultural Sciences found that injecting a benign Xylella fastidiosa EB92-1 bacteria biocontrol into infected citrus trees over a period of six years reduced the incidence of trees with severe HLB symptoms. The potential result is providing growers with a strategy to keep trees alive and productive longer even when infected with the citrus greening bacterium.

    Donald Hopkins, an emeritus professor of plant pathology at the UF/IFAS Mid-Florida Research and Education Center, conducted three trials in central and eastern Florida with commercial groves of Valencia orange and Rios grapefruit trees at different maturity stages. All of the trees tested positive for citrus greening disease at the beginning of the trial but had varying ranges of symptoms from asymptomatic, mild to severe. Trees in the trials included young 2-year-old and mature (greater than 20-year-old) trees.

    “Using EB92-1 provided a level of control of HLB in two mature citrus tree trials and in a trial initiated in young 2-year-old trees,” said Hopkins. “This biocontrol strain has the potential to prevent or delay severe symptoms of HLB and prevent the loss of production both in mature and young citrus trees.”

    All trees in the trials remained positive for HLB throughout the six-year trial. The injections of EB92-1 did not prevent or reverse infection of HLB. But key findings indicated that trees that were treated had less increase in symptoms than untreated trees. Injected trees also had increased yield than untreated trees. In mature trees, results from the trials indicated that the most effective control of HLB may require once-a-year treatment for at least the first 2-3 years. Retreatment may be required yearly for best biocontrol.

    Using EB92-1 especially combined with nutrition, fertilizer and pesticide best management practices could prolong the life and productivity of citrus trees.

    Hopkins believes that the biological control of HLB by EB92-1 is not from direct competition with the HLB pathogen since the EB92-1 bacterium operates in a tree’s xylem and the HLB bacterium colonizes the tree’s phloem. Rather the impact in more likely an instance of induced resistance. Induced resistance occurs when a plant’s resistance mechanism is activated by infecting a plant with a pathogen, such as the benign strain EB92-1. In this case, injecting EB92-1 provided some control of HLB in a tree’s tissues not infected with EB92-1 resulting in a slowing of HLB symptoms.

    This research was published online in Plant Disease, the journal of the American Phytopathological Society (APS). The project was partially funded by the United States Department of Agriculture HLB Multi-Agency Coordination (MAC) group and UF/IFAS. This treatment is patented and licensed to an external company but is not currently available to growers. The trials continue in central and eastern Florida. — By Ruth Borger, University of Florida, Institute of Food & Agricultural Sciences

  • Citrus Research Board Secures Immense Support from Citrus Growers

    California citrus growers voted to continue their support of the Citrus Research Board (CRB) by a broad margin in a state-mandated referendum.

    The just-concluded referendum, which must be held every five years, was conducted by the California Department of Food and Agriculture (CDFA). A majority of eligible citrus producers cast their vote and their support was nearly unanimous – 97.80 percent, representing 99.51 percent of the state’s citrus volume, voted in favor of continuing the CRB.

    CDFA Marketing Branch Chief Joe Monson said, “Since the referendum results exceed the criteria required for continuation stated above, the Department has authorized the Program to continue operating for another five-year period, through September 30, 2027.”

    Over the past five years, the CRB has worked continuously to advance findings within our four research priorities: vectored diseases, pest management, production and post-harvest technology, and new varieties. Much of the research has focused on the deadly disease huanglongbing (HLB) and advancements have been made to keep the infections from spreading in California. The disease has devastated other citrus growing regions, including Florida, but the diligence of California’s growers has kept HLB from entering any of the state’s commercial groves.

    “We are pleased to once again receive the support of the industry,” said CRB President Marcy L. Martin, “and we look forward to continually improving upon the scientific pillars that allow the California citrus industry to thrive.”

    The CRB administers the California Citrus Research Program, the grower-funded and grower-directed program established in 1968 under the California Marketing Act as the mechanism enabling the State’s citrus producers to sponsor and support needed research. More information about the Citrus Research Board may be found at www.citrusresearch.org.

  • Areawide, Coordinated ACP Treatment Participation More Important Than Ever For Citrus Growers

    Citrus Branch Infected by Citrus Disease Vector — Asian Citrus Psyllid

    As the threat of Huanglongbing (HLB) continues, industry members know that the best way to prevent HLB from infecting our groves is to limit populations of the Asian citrus psyllid (ACP), which spread the deadly disease. This winter, it’s critically important for California’s citrus growing operations to actively participate in local, area-wide or coordinated treatments to further boost our industry’s efforts in the fight against the ACP.

    Over the past year, ACP detections have been spiking throughout areas of the state where it has not been declared well-established, including parts of the Central Valley and Central Coast. While treatment strategies are different in various regions of the state, participation in area wide or coordinated treatments is crucial in suppressing ACP populations. When we work together by timing treatment applications, we can leverage the strongest counter punch possible by limiting the areas where psyllids find safe harbor to avoid these treatments. In the process, we can protect not only our own groves, but those of our neighbors.

    The cost to manage ACP populations is far less than what the potential costs should HLB spread into our commercial groves. One only has to turn their eyes to Florida for a crystal ball’s view into our future should we not take action. While we have successfully prevented HLB detections in California’s commercial citrus groves thus far, I encourage growers to invest in this “insurance policy” to provide the best continued protection we have against this formidable opponent.

    Florida Citrus Orchard Dying of Huanglongbing disease

    Our industry continues to make strides in the fight against HLB and the ACP, but we’re stronger when we work as a collective. It is important to connect with your local grower liaison or pest control district, or view the treatments schedules on CitrusInsider.org for details on treatments in your area, as the preferred timing of treatments will vary per region. For more information on ACP treatments and effective materials, see the University of California’s UCIPM Pest Management Guidelines for Asian Citrus Psyllid. If you suspect ACP or HLB in your grove, please notify the California Department of Food and Agriculture Pest Hotline at 1-800-491-1899. — By Jim Gorden, Chair, Citrus Pest & Disease Prevention Committee

  • Costa Rican Orange Production and Exports Expected to Rebound in 2022 Despite Battle with HLB

    After overcoming COVID-related labor and supply chain disruptions, Costa Rica’s orange production is expected to rebound to 300,000 metric tons in 2022, pushing total orange juice exports slightly higher to 33,000 metric tons. Despite some success in mitigating the worst impacts of citrus greening, the disease is expected to limit near-term prospects for Costa Rican industry growth.

    Commercial orange production is concentrated in the northern part of Alajuela province (around Los Chiles, Guatuso, and Upala) and in the northern part of Guanacaste province (near the border with Nicaragua in an area known as Santa Cecilia).

    Figure 1. Map of Costa Rican Growing Area (highlighted in red)

    Two companies, TicoFrut and Del Oro, control most of the production and practically all processing of oranges in the country. TicoFrut is the largest company in the sector. TicoFrut’s plantations are located primarily in the province of Alajuela (near the border with Nicaragua) and in Nicaragua. Oranges from the Nicaraguan plantations are trucked across the border in Los Chiles for processing at TicoFrut’s plant located in Muelle, San Carlos, about 50 miles to the south of the border. Del Oro’s plantations are in the province of Guanacaste, near the border with Nicaragua. Oranges are also grown in other regions of the country including Acosta (near the Central Valley) and Nandayure in Guanacaste. However, oranges from those areas are mostly sold as fresh fruit in the local market.

    There are also some medium and small size independent producers near the areas where the two processing plants are located. While the larger operations have been stable and plan their activities with a longer-term view, the smaller independent producers tend to supply the processing market (rather than selling into the fresh fruit market) in response to short-term price fluctuations. Smaller producers have also been exiting orange production altogether over time as orange yields and orange prices have made other activities more attractive.

    Harvest is mainly from January to May, with peak production in March and April. The vast majority of commercial oranges are processed for juice concentrate for the export market. A relatively small volume of fresh fruit is sold for local consumption, and processing plants also sell small volumes of juice to local food processors for branded products and for further processing.

    TicoFrut has orange plantations in Nicaragua, near the border. Growing conditions are favorable in that area, and land prices and labor costs are generally lower. Costa Rican processors have partnered with Nicaraguan businesses to plant orange groves in Nicaragua for processing in Costa Rica. According to data from the Government of Costa Rica, the country imported 69,800 metric tons (MT) of fresh oranges from Nicaragua in 2020, compared to 56,644 MT during 2019. Imports from Nicaragua during 2021 reached 66,444 MT through October.

    Within orange area planted, farmers are gradually increasing the number of trees per hectare by using the “Flying Dragon” pattern, which supports higher tree density, easier farm management, and lower costs per hectare. This innovation has allowed farmers to significantly increase tree density, moving up from 300 – 450 trees/ha under traditional planting patterns to 800 to 900 trees/ha with the Flying Dragon. FAS/San José anticipates major growers to direct investments toward replanting existing area with new trees and new patterns, rather than increasing area planted, in the near- to medium-term.  Local industry estimates area planted at around 21,000 hectares (ha) and 7.4 million orange trees, including the area planted on the Nicaraguan side of the border. With reports of reductions in area planted to oranges – as citrus greening disease changes yields and profitability calculations – FAS/San José expects area planted to remain flat or decline slightly in 2022 as the effects of citrus greening persist and as major growers concentrate on improvements to current production areas through replanting and irrigation investments.

    Citrus greening disease was first identified in Costa Rica in 2011 and remains a major concern for producers. Citrus greening is reportedly endemic throughout most of the country’s growing areas, increasing costs, decreasing yields, adding uncertainty to future production plans, and limiting growth of production area and volumes. The largest farms have had some success mitigating the effects of the disease by establishing strict controls, including constant farm surveillance, inspection of all farms, and eradication of 100 percent of affected plants. Better capitalized producers use agrochemicals and biological controls (a wasp, called tamarixia radiata, that feeds on the vector of the disease) as part of their preventive measures. The disease has reportedly caused production area to be reduced or abandoned, but FAS/San José has not been able to confirm the extent. Smaller producers, less capable of and less likely to invest in agrochemicals and biological controls, have reportedly suffered heavier losses.

    FAS/San José forecasts total production to increase by 3 percent to 300,000 MT in MY 2021/2022. The largest farms have stabilized production levels through consistent citrus greening management over the last few years, resulting in smaller overall production fluctuations. In 2020/2021, the sector benefited from a more predictable, formalized government migration process for temporary laborers during the pandemic. Securing imported labor supplies was crucial not only for the 2021 harvest, but also for agricultural management practices earlier in the growth cycle (e.g., during flowering) that require imported labor. According to industry sources, fuel and fertilizer costs have increased approximately 30 percent in 2021, adding to the not insignificant additional costs of managing citrus greening – agrochemicals, integrated pest management, and eradication of affected plants.

    Costa Rica exports most of its orange production as frozen concentrated orange juice (FCOJ); single strength fresh orange juice exports represent less than 25 percent of total export volume. According to information from the Costa Rican Trade Promotion Board (PROCOMER), calendar year 2020 juice exports to all destinations amounted to 21,800 MT (valued at $34.6 million), down considerably from 32,897 MT (valued at $50 million) in 2019. Trade data through October 2021 show total exports rebounding to 30,819 MT and $42.9 million, respectively.

    FAS/San José expects 2021/22 total exports to increase slightly to 33,000 MT. The United States continues to be Costa Rica’s leading destination for orange juice exports in 2021. Total exports to the United States through October 2021 were 16,582 MT (valued at $31.1 million), already surpassing the 13,177 MT (valued at $26.9 million) shipped to the United States in 2020. Costa Rican orange juice enters the United States duty free under the Central American-Dominican Republic Free Trade Agreement. — By Victor Gonzalez, USDA Foreign Agricultural Service

  • HLB Quarantine Expansion Connects Boundaries in Jurupa Valley and Riverside Areas

    Effective Dec. 6, 2021, the California Department of Food and Agriculture (CDFA) has expanded the Huanglongbing (HLB) quarantine boundaries in Riverside and San Bernardino counties in the Jurupa Valley and Riverside areas to create one quarantine area, connecting parts of Orange, Los Angeles, Riverside and San Bernardino counties. A map of the boundary expansion can be found below and at https://www.cdfa.ca.gov/plant/hlb/regulation.html#maps.

    Additionally, effective Dec. 6, 2021, CDFA is expanding the Asian citrus psyllid bulk citrus quarantine zone 6 in Riverside and San Bernardino counties to reflect the HLB boundary expansion. A map of the proposed new boundaries can be found at https://www.cdfa.ca.gov/citrus/pests_diseases/acp/regulation.html.

    For any questions regarding the regulations or quarantine area, please email Karina Chu at Karina.Chu@cdfa.ca.gov or call 916-274-6300.

  • NIFA Invests Nearly $11M to Combat & Prevent Citrus Greening Disease

    The U.S. Department of Agriculture’s (USDA) National Institute of Food and Agriculture (NIFA) announced an investment of nearly $11 million for research to combat Huanglongbing (HLB), commonly known as citrus greening disease. HLB, caused by an insect bacterium, is the most severe threat to global citrus production.

    “NIFA’s Emergency Citrus Disease Research and Extension program brings the nation’s top scientists together with citrus industry representatives to find scientifically sound solutions to combat and prevent HLB at the farm-level,” said NIFA Director Dr. Carrie Castille. “This year’s awards represent all three major U.S. citrus growing regions and include possible solutions ranging from blocking HLB transmission from inside the insect vector to utilizing novel anti-microbial peptides to treat HLB-infected trees.”

    The fiscal year 2021 five funded Emergency Citrus Disease Research and Extension projects include:

     

    • Texas A&M AgriLife Research will leverage public-private partnerships between state agencies, universities, USDA’s Agricultural Research Service, and the citrus industry to pursue advanced testing and commercialization of promising HLB therapies and extend outcomes to stakeholders. ($7,000,000)
    • University of California, Riverside will build on previous work and evaluate the performance of 300 hybrid citrus trees in established trials to map HLB tolerance/resistance genes and release superior new rootstocks. ($1,499,998)
    • University of Florida seeks to develop a bacterial pathogen transmission blocking strategy (specifically to block Candidatus Liberibacter asiaticus, the pathogen that causes HLB) toward mitigation of citrus greening-related losses in an integrated pest management framework. ($1,020,810)
    • University of Florida’s project will support the needs of both commercial and residential citrus growers by comparing new tools to support young trees and develop management recommendations for the incorporation of each tool into production and residential settings. ($750,000)
    • University of Florida aims to introduce and transfer the natural HLB resistance present in Australian limes into conventional citrus to produce HLB-resistant Australian lime hybrid rootstocks and deploy these hybrids to protect susceptible citrus scions against HLB. ($500,000)

    Background: Huanglongbing (HLB) is considered the most destructive disease in citrus growing regions worldwide and has become the greatest challenge for the U.S. citrus industry. Currently, HLB has no cure.  Since HLB’s initial U.S. detection in 2005, citrus acreage and production in Florida has decreased by 60 percent and 80 percent, respectively. The disease has spread to all citrus-producing states, including Texas and California. Although citrus greening is a serious threat to the citrus industry worldwide, significant progress has been made to coordinate a multipronged approach for citrus greening management and suppression of the Asian citrus psyllid, an insect that carries and spreads HLB, through expanding partnerships with USDA’s Animal and Plant Health Inspection Service, states, universities, and private partners.  Learn more about HLB.

    Asian Citrus Psyllid, the insect responsible for the spread of the citrus-killing disease HLB

    NIFA invests in and advances agricultural research, education, and Extension across the nation to make transformative discoveries that solve societal challenges. NIFA supports initiatives that ensure the long-term viability of agriculture and applies an integrated approach to ensure that groundbreaking discoveries in agriculture-related sciences and technologies reach the people who can put them into practice. In FY2020, NIFA’s total investment was $1.95 billion.

    Visit our website: www.nifa.usda.gov; Twitter: @USDA_NIFA; LinkedIn: USDA-NIFA.

  • University of Florida Researchers Publish Award-Winning Findings on Grove Design to Produce Oranges Under HLB

    University of Florida Institute of Food & Agricultural Sciences —The American Society for Horticultural Science recently honored University of Florida scientists for new guidelines citrus growers may apply to their operations. The researchers study ‘Valencia’ orange production while trees are under the most serious citrus disease worldwide.

    “The 7-year study broke new ground on data we provide to local citrus growers who remain in business despite huanglongbing, or HLB,” said Ronald D. Cave, Director of the University of Florida Institute of Food and Agricultural Science’s Indian River Research and Education Center in Fort Pierce (UF/IFAS-IRREC).

    A few of the findings citrus growers may employ immediately from the study are:

    • High-density plantings produce more fruit—from 86% up to 300% more than trees not planted in high-density configurations under HLB.

    • The study showed that advanced management practices that included high tree density, fertigation, and drip irrigation led to higher fruit yield.

    • Additional research is needed to determine optimal fertilization rates for high-density sweet orange orchards under HLB-endemic conditions

    The award-winning publication, “Sweet Orange Orchard Architecture Design, Fertilizer, and Irrigation Management Strategies under Huanglongbing-endemic Conditions in the Indian River Citrus District,” appears in the December 2020 issue science of the scientific journal HortScience. The paper describes the scientists’ hypothesis, the entire research procedure, outcomes, and recommendations for further research.

    Members of the American Society for Horticultural Science (ASHS) Fruit Publication Selection Committee wrote about the paper’s significance. “Huanglongbing, also known as citrus greening, affects all citrus cultivars and causes serious tree decline. It is currently a major threat to the citrus industry. The results can influence the whole citrus industry to deal with HLB including orchard architecture design, fertilizer, and irrigation management strategies.”

    Rhuanito “Johnny” Ferrarezi and his colleagues conducted experiments to determine the variables that promote healthy fresh fruit harvests with the presence of HLB. Ferrarezi, along with fellow professors Mark Ritenour and Alan Wright, accepted the “Outstanding Fruit Publication Award” for papers published in 2020 at the ASHS annual meeting awards ceremony in Denver, Colorado, Aug. 6. Ferrarezi is an Assistant Professor of Citrus Horticulture; Ritenour, Professor of Postharvest Technology; Wright, Professor of Soil and Water Science.

    Others who contributed to the research and the award-winning publication are Arun D. Jani, a post-doctoral research assistant; Thomas James III, who manages citrus research groves; and Cristina Gil, an agricultural research assistant.

    “We strive to keep citrus growers in business even though HLB is reducing the profitability of infected trees over time,” said Ferrarezi. “The point is to sustain younger trees for a number of harvests to produce the healthy, delicious fruit that made the Indian River District famous.”

  • Growers Urged to Participate in Kern County Coordinated Treatment

    Citrus Pest & Disease Prevention Program — A significant number of Asian citrus psyllid (ACP) detections in Kern County – more than 115 since this time last year – is a stark reminder to remain vigilant against the pest and the deadly disease it can spread, Huanglongbing (HLB). Last week, an adult ACP was confirmed from a commercial citrus trap in the east Edison area. This detection, along with two recent detections in Arvin residential properties, provides more urgency for growers with citrus east and south of Bakersfield to participate in the upcoming coordinated treatment.

    The preferred timing of the treatment is mid-August through mid-September to prevent ACP populations from building on the fall foliar flush. Coordinated treatments like this were done during the same time period in 2018 and 2019 with great success in significantly suppressing ACP populations in commercial citrus orchards.

    The San Joaquin Valley ACP/HLB Task Force recommends growers treat all commercial citrus orchards located south or east of Bakersfield – including young, non-bearing trees. For more information on ACP treatments and effective materials, see the University of California’s UCIPM Pest Management Guidelines for Asian Citrus Psyllid.

    Past coordinated treatments in the county have been successful in suppressing ACP populations. By participating in this late summer/early fall treatment, Kern County can greatly reduce the number of psyllids, and thus reduce the risk of HLB being transmitted to our commercial citrus.

    If you suspect ACP 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 or 559-730-8691 or the Kern County Agricultural Commissioner’s Office at 661-868-6300.