By Chris Oswalt During this time of the year, Florida growers should be aware of the potential for the development of citrus brown rot disease. It can infect fruit at color break. If severe, the disease can cause a significant amount of infected fruit to drop. For this reason, groves with a history of brown rot in areas that recently …
Phytophthora Increasing; HLB Complicates Control
Phytophthora incidences are increasing in Florida citrus groves, plant pathologist Ozgur Batuman reported during a May 21 presentation. Phytophthora diseases include foot rot of trunk and limbs, root rot and brown rot. Batuman, a University of Florida Institute of Food and Agricultural Sciences associate professor, said these diseases led to yield reductions of 3% to 6% per year even prior …
Procedures Revised for Sweet Orange Scab in California
The conditions for the interstate movement of citrus nursery stock and packinghouse procedures for citrus fruit from sweet orange scab (SOS) quarantined areas in California were recently revised. The actions were taken by the U.S. Department of Agriculture Animal and Plant Health Inspection Service (USDA APHIS). The actions update the “APHIS-Approved Packing House Procedures for Elsinoë australis, Causal Agent of …
Diseases Easier to Prevent Than to Control
Plant pathologist Ozgur Batuman recently warned that two citrus viral diseases not currently in Florida are highly suited to the state’s climate and would likely impact production if found there. They are citrus leprosis and citrus yellow vein clearing virus (CYVCV). Batuman, a University of Florida Institute of Food and Agricultural Sciences associate professor at the Southwest Florida Research and …
Citrus Greening Quarantine Expanded in Texas
Agriculture officials have expanded the areas quarantined for citrus greening (huanglongbing; HLB), caused by Candidatus Liberibacter asiaticus, in Texas. All of Zapata County has been added to the quarantined areas. The action was taken by the U.S. Department of Agriculture Animal and Plant Health Inspection Service (APHIS) in cooperation with the Texas Department of Agriculture (TDA). The action was taken …
Florida Citrus Black Spot Quarantines Expanded
Agriculture officials have increased the existing citrus black spot (CBS) quarantine area in Florida and established a new quarantine area. The U.S. Department of Agriculture Animal and Plant Health Inspection Service (USDA APHIS) and the Florida Department of Agriculture and Consumer Services Division of Plant Industry (FDACS DPI) took these actions. CBS is a fungal disease that leaves fruit speckled …
California Sweet Orange Scab Quarantine Area Expanded
The U.S. Department of Agriculture Animal and Plant Health Inspection Service (USDA/APHIS) is expanding the quarantine area in California for Elsinoë australis, the fungal causal agent of sweet orange scab (SOS). The expansion aligns with the state interior quarantine that the California Department of Agriculture (CDFA) implemented Oct. 1, 2023. SOS infection causes scab pustules that give fruit a corky …
Update on Citrus Canker Quarantined Areas in Texas
Federal and Texas agriculture officials announced on April 26 they were establishing four new quarantined areas for citrus canker in Hidalgo County and expanding one existing canker quarantined area in Cameron County. The actions by the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (USDA APHIS) and the Texas Department of Agriculture (TDA) were taken to prevent …
Greening Addressed at International Epidemiology Workshop
Fundecitrus researchers Renato Bassanezi and Silvio Lopes in April addressed the citrus greening situation in Brazil from an epidemiological point of view during the International Epidemiology Workshop held in Brazil. Lopes presented work on the potential of citrus plants in backyards being a source of Candidatus Liberibacter asiaticus (the bacterium associated with greening) inoculum for commercial orchards. Fundecitrus has been …
Phytophthora: A Complex Problem
While the recent Florida Citrus Growers’ Institute presentations focused mainly on HLB, other topics were addressed, including phytophthora root rot. This disease has become more problematic in recent years. Megan Dewdney, University of Florida Institute of Food and Agricultural Sciences associate professor of plant pathology, spoke on the topic. She noted that phytophthora already is a complex problem and that …
Factors That Impact Control of Citrus Leprosis
Several factors can influence the period of citrus leprosis control after acaricide applications, according to a study by Daniel Andrade, a professor and researcher from São Paulo State University in Brazil. The research aimed to better understand how these factors can affect and increase the leprosis control period. “We studied acaricides, the moment of application of the acaricide, the presence …
New and Expanded Canker Quarantines in Texas
Federal and Texas agriculture officials announced they are establishing four new quarantine areas for citrus canker in Brazoria and Harris counties, Texas. They are also expanding three existing quarantine areas for citrus canker in Brazoria, Fort Bend, Galveston and Harris counties. The U.S. Department of Agriculture Animal and Plant Health Inspection Service (USDA APHIS) and the Texas Department of Agriculture …
Louisiana HLB Quarantine Area Expanded
Federal agriculture officials, in cooperation with Louisiana agriculture officials, have established a federal quarantine area for huanglongbing (HLB; citrus greening), caused by Candidatus Liberibacter asiaticus, in all of Saint Charles Parish in Louisiana. The U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (USDA APHIS) took the action in cooperation with the Louisiana Department of Agriculture and Forestry (LDAF). …
Yellow Vein Clearing Virus Spreads in California
Positive identifications of citrus yellow vein clearing virus (CYVCV) have been found in the Hacienda Heights area of Los Angeles County. The U.S. Department of Agriculture’s Animal and Plant Health Inspection Service confirmed the identifications during the California Department of Food and Agriculture’s (CDFA) routine multi-pest survey. This is the second area in California where CYVCV has been detected. The …
Alabama Designated as Commercial Citrus Producer
The U.S. Department of Agriculture Animal and Plant Health Inspection Service (USDA APHIS) announced it has designated Alabama as a commercial citrus-producing area. This action provides Alabama with protections that are afforded under the citrus canker regulations applying to commercial citrus-producing states. USDA APHIS regulates the interstate movement of certain plants, plant parts and other articles from areas of the …
Phytophthora Diseases in California Citrus
Greg Douhan with University of California Agriculture and Natural Resources (UCANR) recently wrote about phytophthora diseases in California citrus. Edited excerpts follow: There are at least four species of Phytophthora species (P. citrophthora, P. parasitica, P. syringae and P. hibernalis) associated with citrus in California. The three diseases in citrus caused by these fungal-like pathogens are phytophthora root rot, phytophthora …
Australia Seeks Vaccine-Like Solution to CTV
Australian scientists are developing a vaccine-like solution to arm citrus growers with an effective way to combat citrus tristeza virus (CTV), a significant challenge for the Australian citrus industry. The $1.5 million initiative is being delivered through Hort Innovation and collaboratively led by the University of Queensland, the New South Wales Department of Primary Industries (NSW DPI) and Auscitrus. Researchers …
Diseases Without Borders: Leprosis and Yellow Vein Clearing Viruses
By Ozgur Batuman Plant virus diseases are unusually difficult to manage if introduced into new production sites. Citrus-infecting viruses, particularly those spread by insect vectors, are no exception to this. Florida is regularly challenged by a barrage of invasive pests and pathogen species that could devastate the citrus industry. Viruses causing citrus leprosis and citrus yellow vein clearing diseases are …
The Status of Citrus Canker in Georgia
Citrus canker was found for the first time in Georgia this past season. Unfortunately, it may be here to stay. Jonathan Oliver, University of Georgia (UGA) assistant professor and small fruits pathologist, talked about the disease during a citrus meeting in Valdosta, Georgia, on Aug. 9. He emphasized that Georgia producers may have to learn to live with the disease …
Brown Rot Could Be on the Horizon for Florida
By Megan Dewdney It is summer in Florida, and the early fruit are maturing. This is always a risky time for brown rot in early sweet oranges and grapefruit cultivars. The summer rains have been happening, but they have been intermittent depending on location. This means that phytophthora propagule counts may vary depending on how much rain has occurred in …