Below you'll find a list of all posts that have been categorized as “Diseases”
By Megan M. Dewdney, Eva L. Mulandesa and Mark A. Ritenour Greasy-green began to be reported as a problem in Florida by fresh fruit packers and growers around 2020. The disorder, with green blotches on the grapefruit surface, appeared to be different from other known rind disorders. The effect was costly for growers and packers, with reported losses between $20,000 …
The California Department of Food and Agriculture (CDFA) has announced there is one vacancy on the Citrus Pest and Disease Prevention Committee (CPDPC). The committee advises the CDFA secretary on activities associated with the statewide citrus-specific pest and disease work plan. The work plan includes but is not limited to outreach and education programs as well as programs for surveying, …
A new initiative aims to strengthen the University of Florida Institute of Food and Agricultural Sciences’ (UF/IFAS) ability to respond rapidly when a new invasive pest or plant disease threatens. Edward “Gilly” Evans, director of the UF/IFAS Tropical Research and Education Center (TREC), launched the Challenge 250 initiative. Named in recognition of the nation’s 250th anniversary, it aims to raise …
The U.S. Department of Agriculture Animal and Plant Health Inspection Service (APHIS) announced Sept. 1 it was increasing the area quarantined for citrus black spot (CBS) in Florida. APHIS is expanding the quarantined area by adding eight sections in Charlotte County, 18 sections in Collier County, one section in Glades County, two sections in Hendry County, four sections in Lee …
Fungal foliar diseases significantly threaten commercial citrus production by reducing fruit packout and overall crop yield. Tangerines and mandarins are highly susceptible to these pathogens, particularly Alternaria brown spot and citrus scab. In a presentation at the recent Citrus & Specialty Crop Expo, Megan Dewdney, University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) plant pathologist, outlined proactive management …
Citrus canker disease is an isolated threat in the cold-hardy citrus region that growers should remain aware of. Jonathan Oliver, University of Georgia (UGA) assistant professor and small fruits pathologist, recently discussed the disease and its potential impact in cold-hardy citrus. “Canker has been found in Georgia, as reported several years ago. It seems to be very isolated in a …
The California area quarantined for sweet orange scab (SOS) in the Burbank, Los Angeles and Long Beach areas of Los Angeles County and the Anaheim and Garden Grove areas of Orange County has been expanded. The expansion was made by the U.S. Department of Agriculture Animal and Plant Health Inspection Service (APHIS) in cooperation with the California Department of Food …
California Department of Food and Agriculture (CDFA) and U.S. Department of Agriculture (USDA) officials have confirmed the detection of HLB in one tree in a residential property in the city of Calexico, Imperial County, California. This is the first HLB detection in a tree in Imperial County. In November 2025, an Asian citrus psyllid (ACP) was confirmed positive in Imperial …
Although huanglongbing (HLB) disease was highlighted in the citrus section of the U.S. Department of Agriculture Animal and Plant Health Inspection Service’s (USDA APHIS) recent PPQ (Plant Protection and Quarantine) 2025 Annual Report, the report also noted efforts against other citrus diseases. Those diseases include citrus canker, citrus yellow vein clearing virus, sweet orange scab and citrus black spot. The …
A recent article from Alabama A&M and Auburn universities highlighted the major issues facing citrus growers in southern Alabama’s Baldwin and Mobile counties. FREEZES One of the biggest obstacles that citrus growers face is highly variable weather, including late-season freezes. Jacob Kelley, an Alabama Extension commercial horticulture agent at Auburn University, said winter temperatures that might swing from 80 to …
Federal and state agriculture officials have taken actions regarding Mediterranean fruit fly (Medfly) and sweet orange scab (SOS) quarantines in California. The U.S. Department of Agriculture Animal and Plant Health Inspection Service (APHIS) in cooperation with the California Department of Food and Agriculture (CDFA) updated the quarantines. MEDFLY QUARANTINE REMOVED The agencies removed the Medfly quarantine in Alameda and Santa …
The U.S. Department of Agriculture Animal and Plant Health Inspection Service and the California Department of Food and Agriculture (CDFA) confirmed the positive identification of citrus yellow vein clearing virus (CYVCV) in a residential citrus tree in the Lodi area of San Joaquin County. The plant sample was confirmed positive for CYVCV on July 7 following a routine multi-pest survey …
In Florida, the soilborne phytophthora pathogens — primarily Phytophthora nicotianae and Phytophthora palmivora — are the leading causes of root rot, crown rot and foot rot. Two University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) researchers recently wrote about phytophthora management in cold-hardy citrus. The authors are Assistant Professor and Extension Specialist Muhammad Shahid and postdoc Carlos Aucique-Perez, …
Postharvest diseases such as green mold (Penicillium digitatum), blue mold (P. italicum) and sour rot (Geotrichum citri-aurantii) cause heavy losses in citrus crops. These fungi thrive in warm, humid regions and have developed resistance to common fungicides such as imazalil, thiabendazole and pyrimethanil, driving up costs and raising environmental and regulatory concerns. A new study offers hope using a simple, …
A new study has identified several fungal pathogens associated with preharvest sweet orange fruit spoilage. It provides insights that could help citrus growers better understand and manage fruit rot problems in the grove. The research, “Morphological Identification of Fungi Associated with Preharvest Spoilage of Sweet Orange (Citrus sinensis L.) Fruit in Bilo Nopha, Southwestern Ethiopia,” was published in the journal …
Southeastern residents increasingly support stronger protections against agricultural disease threats as concerns grow over food-system disruptions, say researchers at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS). Findings from an August 2025 public interest survey distributed to 1,035 Southeast residents reflect growing public concern about how agricultural threats can affect food systems, public health and disaster preparedness. …
By Lauren Fessler Mathews, Ana Redondo and Ozgur Batuman Citrus canker continues to impact Florida citrus, increasing premature fruit drop and decreasing yield and fruit quality. While copper sprays have long been relied upon to control this disease, concerns about environmental impact and possible resistance development have led to efforts to find sustainable alternatives. Previous studies have shown that plant …
The U.S. Environmental Protection Agency (EPA) released its draft Fungicide Strategy and is inviting the public to weigh in. The draft strategy identifies practical, science-based protections that fungicide users can adopt to safeguard more than 1,000 federally endangered and threatened species. The strategy also aims to preserve the flexibility that states, growers and applicators need. EPA is opening this draft …
The U.S. Department of Agriculture Animal and Plant Health Inspection Service (APHIS) in cooperation with the California Department of Food and Agriculture (CDFA) have expanded the area quarantined for sweet orange scab (SOS). The expansion is in the Irvine area of Orange County and in the La Puente area of Los Angeles County in California. QUARANTINE ACTIONS APHIS is expanding …
By Megan Dewdney Algal spot is rarely a top concern for growers until it seems to be suddenly everywhere. Is the disease a major concern or a nuisance? It depends. If the disease is only in a few locations, then the management goal is making sure that the disease is not spreading too widely. If many trees are affected, the …
