California Fruit and Vegetable

Category: Pest/Disease Management

  • Citrus Canker in Nursery Stock Sold to CA, CDFA & USDA Take Action to Identify & Destroy Affected Plants

    Citrus Pest & Disease Prevention Program — The United States Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) has confirmed the presence of citrus canker disease in a nursery in South Carolina. The nursery sells plants to consumers through online sales, including four locations in California since August 2021. Retail nurseries did not receive these plants.

    Citrus canker causes citrus leaves and fruit to drop prematurely, and results in lesions on citrus leaves, stems and fruit. Fruit infected with the bacterium that causes citrus canker (Xanthomonas axonopodis) is safe to eat, but it may not be marketable because of the lesions. The disease affects all citrus varieties. Citrus canker is not harmful to people or animals.

    Together with state partners, APHIS is working to collect and destroy the plants shipped to consumers in 11 states and trace plants that were sold to determine additional locations of potentially infected plants. The states include Alabama, California, Florida, Georgia, Louisiana, Mississippi, Nevada, Oregon, South Carolina, Texas and Washington.

    The California Department of Food and Agriculture (CDFA) was notified that four residential properties throughout the state had ordered citrus nursery stock from the South Carolina nursery. Upon being notified of the recall, CDFA staff successfully verified that one order was not filled, removed and destroyed the recalled trees from two of the three remaining residential properties and is working to connect with the recipients of the final shipment (as of March 9). All additional host plants on these properties were surveyed and sampled for citrus canker disease and submitted for analysis, and delimitation surveys will also be conducted around these locations. These swift actions by APHIS and CDFA are focused on protecting the citrus industry as well as nurseries and other establishments that sell citrus plants wholesale and direct to consumers.

    Currently, citrus canker is found throughout Florida and in limited areas of Louisiana and Texas. APHIS is working with state partners to contain the disease, and federal and state quarantines exist in these states. Additionally, citrus canker was recently confirmed in Alabama, and APHIS is working with state partners to establish a federal quarantine to parallel the state quarantine.

    If you live in one of the 11 states and bought citrus plants online that came from South Carolina between Aug. 5, 2021 – Feb. 17, 2022, please keep your plants for now. If you purchased a plant or plants that might be infected, APHIS and/or state officials will contact you in the next several days to collect and properly dispose of any plants purchased from the nursery. You can also call your local USDA office with additional questions. Contact information can be found at www.aphis.usda.gov/planthealth/sphd.

    To learn more about APHIS’ regulations for citrus canker, please visit https://www.aphis.usda.gov/aphis/ourfocus/planthealth/plant-pest-and-disease-programs/pests-and-diseases/citrus/citrus-canker.

    For questions about citrus canker in California or other pests or diseases, please call CDFA’s toll-free Pest Hotline at 1-800-491-1899.

  • Fresno County Vacancy on Citrus Pest & Disease Prevention Committee

    The California Department of Food and Agriculture is announcing one vacancy on the Citrus Pest and Disease Prevention Committee. The Committee advises the CDFA Secretary on activities associated with the statewide citrus specific pest and disease work plan that includes, but is not limited to, outreach and education programs and programs for surveying, detecting, analyzing, and treating pests and diseases specific to citrus.

    The members receive no compensation but are entitled to payment of the necessary travel expenses in accordance with the rules of the Department of Personnel Administration.

    The Committee member vacancy exists for one grower representative from Fresno County, the member term expires on September 30, 2022. Applicants should have an interest in agriculture and citrus pest and disease prevention.

    Individuals interested in being considered for a committee appointment should send a brief resume by March 31, 2022 to the California Department of Food and Agriculture, Citrus Pest and Disease Prevention Division, 1220 N Street, Sacramento, California 95814, Attention: David Gutierrez.

    For additional information, contact: David Gutierrez, Branch Chief, Citrus Pest and Disease Prevention Division at (916) 274-6300, or e-mail David.Gutierrez@cdfa.ca.gov.

  • Grant to Support Affordable Testing to Fight Little Cherry Disease

    Washington State University (WSU) will help cherry growers test more trees for the damaging Little Cherry Disease thanks to a Washington State Department of Agriculture Specialty Crop Block Grant received by the Washington State Tree Fruit Association.

    Named for its most distinct symptom—small, colorless fruit—what growers call ‘Little Cherry’ is a simultaneous outbreak of Little Cherry virus-2 and the X-disease phytoplasma, both of which produce similar symptoms on infected cherry trees and are difficult to tell apart, even by experts. This is more difficult because symptoms are usually noticed only a few weeks before harvest.

    The pathogens are spread in orchards by small insects: the virus by mealybugs, and the phytoplasma by leafhoppers.

    Tests are available for growers to learn if a tree is infected, but they can be expensive. The new three-year, $530,000 grant will help to expand testing capacity at WSU’s Plant Disease Diagnostic Lab in Pullman with more equipment and supplies. This support will reduce testing fees by approximately 50%, to $50 per test.

    “Affordable and available testing is a key element of our industry’s response to Little Cherry Disease” said Jon DeVaney, WSTFA President. “Washington’s cherry growers appreciate the support of the WSDA Specialty Crop Block Grant Program and WSU’s Plant Disease Diagnostic Lab in this effort.”

    “Active, aggressive tree removal is the best way to suppress this outbreak and prevent further spread, and testing is an essential tool to identify trees in the early stages of infection,” said Scott Harper, WSU virologist and director of the Clean Plant Center Northwest. “It will help growers make informed management decisions for their orchards.”

    Harper’s lab supported the initial wave of testing in 2018-2019, and commercial labs took over testing in 2020, but few growers could afford to test every tree that they suspected might be infected.

    “WSU and collaborating laboratories are working hard to provide growers with Little Cherry testing services,” said Tianna DuPont, a WSU Tree Fruit Extension Specialist. “Additional support for the WSU Plant diagnostic lab is essential to provide sustainable robust public diagnostics so growers can identify and quickly manage the multiple problems that attack their trees.”

    Removing infected trees quickly is the best way to fight the disease, as there is no treatment and early removal can limit spread of the virus to nearby trees in an orchard, Harper said. Testing also helps avoid removing a tree exhibiting symptoms that look like the disease, but isn’t infected with little cherry pathogens. — By Scott Weybright, WSU College of Agricultural, Human & Natural Resource Sciences

  • Research Indicates Paint Not Effective At Protecting Young Avocados From Herbicide Drift

    California Avocado Commission — While it is often common practice for fruit growers to apply white latex paint to the bottom 2 to 3 feet of young, newly planted trees in order to provide some protection from herbicide drift, researchers note there is little evidence to prove this practice is effective.

    A recent blog post by Dr. Ben Faber summarized the findings of a California field experiment conducted in 2017 that measured the impact of latex paint in preventing herbicide injury on young almond trees. The block of trees consisted of greenhouse-grown trees in cartons. Nine weeks prior to the herbicide applications, the cartons were removed for trees in the “no paint” and “old paint” sections so their bark could harden off. Two days prior to applying the herbicide, the cartons were removed for the “new paint” trees and then the trees were painted.

    According to the researchers:

    • The paint did not provide significant protection from glyphosate or glufosinate.
    • Tree stress caused by trunk-applied herbicides was lowest in trees with no paint, suggesting that allowing the bark to harden on young trees is an important means of protecting them from herbicide drift.
    • In most treatment combinations, old and new paint applications did not reduce tree stress as effectively as allowing the bark to harden on trees nine weeks prior to application.
    • The most effective means of protecting trunks was installing a carton. However, it is important to remember that once the carton is removed (as the tree matures), there may be green bark present which would be vulnerable to herbicides.

  • 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

  • Black Beans Help Fix Insulin Resistance and Gut Bacteria Balance

    USDA ARS — Adding cooked black beans to a high-fat diet improved sensitivity to insulin and other measures often related to diabetes and restored gut bacteria balance in obese mice, according to a USDA Agricultural Research Service study.

    As little as the mouse-size equivalent of a single serving a day of black beans—about a half cup for a human—lowered insulin resistance 87 percent in obese mice compared to obese mice eating the same high-fat diet without the black beans. Insulin resistance is when a body’s response to the hormone insulin is impaired so glucose in the blood cannot be used for energy, resulting in high blood sugar, a factor often leading to diabetes.

    Mice on the high-fat plus black beans diet also decreased low density lipoprotein (LDL) cholesterol, the so-called bad cholesterol, 28 percent and triglyceride levels 37 percent compared to mice eating the high-fat diet without black beans. These are both risk factors for cardiovascular disease.

    Other diabetes-related biomarkers such as the levels of leptin, glucagon, and a group of inflammatory biochemicals were all significantly better in the mice on the high-fat plus black beans diet.

    The researchers also found that adding black beans to the high fat diet restored the balance of healthier bacteria in the gut, particularly decreasing the ratio of Firmicutes bacteria to Bacteroidetes bacteria in the gut by 64 percent compared to mice on the high fat diet without black beans  and mice on a low fat diet. High ratios of Firmicutes to Bacteroidetes are associated with obesity. Intestinal bacteria associated with inflammation such as Blautia and Clostridium all were significantly reduced in mice fed the high fat plus black beans diet compared to mice on the high fat diet without beans.

    “This research suggests that eating even a small amount of black beans can have multiple health benefits,” said ARS research chemist Wallace Yokoyama with the Healthy Processed Foods Research Unit of the Western Regional Research Center in Albany, California. Yokoyama led the study, which was published in the scientific journal Foods.

    “We also tested if supplementing the high fat diet with individual components from black beans would have the same beneficial impacts on the obese mice and didn’t find the same effects at all. It was only adding whole black beans, and cooked whole beans at that, which had the benefits,” Yokoyama said.

    Perhaps the most interesting scientific information coming from this study, according to Yokoyama, is data to begin determining just how black beans improve insulin resistance. It appears that black beans may inhibit the JNK/c-Jun pathway, a key metabolic pathway that has many but not necessarily well-defined functions including regulating inflammatory responses. Chronic inflammation is believed to be the basis for insulin resistance and other metabolic diseases.

    Black beans, or more precisely black turtle beans (Phaseolus vulgaris), are generally low in fat and high in fiber and protein. They are popular in Latin American, Mexican and Caribbean cuisines as well as in Cajun and Creole cooking. Like all common beans, black beans are native to the Americas. Today, they have been introduced around the world to become known as frijoles negros or poroto negro in Spanish, feijão preto in Portuguese, and karuppu kaaramani and kala ghevada in various regional cuisines of India.

    The Agricultural Research Service is the U.S. Department of Agriculture’s chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in agricultural research results in $17 of economic impact.

  • 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.

  • CDFA Seeking New Grower Representative and Public Member for the Citrus Pest & Disease Prevention Committee

    The California Department of Food and Agriculture (CDFA) is announcing two vacancies on the Citrus Pest and Disease Prevention Committee. The committee advises the CDFA Secretary on activities associated with the statewide citrus specific pest and disease work plan that includes, but is not limited to, outreach and education programs and programs for surveying, detecting, analyzing, and treating pests and diseases specific to citrus.

    Committee member vacancies exists for one grower representative from Fresno County, the member term expires on September 30, 2022, and one public member, the member term expires on September 30, 2025. Individuals interested in being considered for a committee appointment should send a resume by November 15, 2021.

    The members receive no compensation but are entitled to payment of necessary travel expenses in accordance with the rules of the Department of Personnel Administration.

    Applicants should have an interest in agriculture and citrus pest and disease prevention. Individuals interested in being considered for a committee appointment should send a brief resume by November 15, 2021 to the California Department of Food and Agriculture, Citrus Pest and Disease Prevention Division, 1220 N Street, Sacramento, California 95814, Attention: David Gutierrez.

    For additional information, contact: David Gutierrez, Branch Chief, Citrus Pest and Disease Prevention Division at (916) 274-6300, or e-mail David.Gutierrez@cdfa.ca.gov. — Citrus Pest & Disease Prevention Program