Stem Pitting Could Develop in Florida Citrus

Ernie NeffDiseases

Citrus tristeza virus (CTV) stem pitting, which causes severe problems in Asia and other places, could develop in Florida, according to plant pathologist Amit Levy. The University of Florida Institute of Food and Agricultural Sciences researcher at the Citrus Research and Education Center discussed the disease at this year’s virtual Citrus Expo. Noting that “early detection is essential,” Levy said … Read More

Phosphite Best for Algal Spot

Ernie NeffDiseases

Algal spot had rarely been seen in Florida groves until fairly recently, Megan Dewdney reported in a virtual Florida Citrus Growers’ Institute presentation. The University of Florida Institute of Food and Agricultural Sciences plant pathologist said she started hearing from concerned orange growers within the past five years. Those growers told her that copper, the historical recommendation for the disease, … Read More

Viroid Found on Georgia Citrus

Ernie NeffDiseases

Hop stunt viroid (HSVd) was found on citrus in Georgia for the first time this year. University of Georgia Cooperative Extension warns that HSVd and other viroids could pose a threat to the state’s growing citrus industry in susceptible varieties. Leaf samples were collected in May and June from 12 different citrus plants in two nurseries in southern Georgia. Nine … Read More

Black Spot and Production Guide Updates

Ernie NeffDiseases

Megan Dewdney recently provided information about positive results from fungicide trials for citrus black spot, as well changes to the new Citrus Production Guide. Dewdney is a plant pathologist with the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS), working at the Citrus Research and Education Center. Dewdney conducted the fungicide trials for black spot in a 20-year-old … Read More

Phytophthora Root Rot Management

Tacy CalliesDiseases

By Evan G. Johnson As September winds down, the fall root flush is starting and will continue through November/December. This is the largest root flush of the year that stores carbohydrate reserves for next spring. Coming out of the rainy season, phytophthora has had the chance to build up plenty of inoculum, especially in groves with a history of root … Read More

Citrus Disease: What to Watch for in Georgia

Tacy CalliesDiseases

The citrus greening disease (huanglongbing or HLB) that has devastated Florida’s citrus industry over the past decade has not affected Georgia commercial production. However, growers should still be aware of the potential danger it can bring. According to Jonathan Oliver, fruit pathologist and Extension specialist in the Department of Plant Pathology at the University of Georgia (UGA), all confirmed HLB-positive … Read More

APHIS Annual Report Highlights Citrus Efforts

Tacy CalliesDiseases, Pests

The U.S. Department of Agriculture Animal and Plant Health Inspection Service (APHIS) recently released an annual report titled “Plant Protection and Quarantine: Helping U.S. Agriculture Thrive — Across the Country and Around the World.” The document includes updates on efforts to manage citrus diseases. “PPQ (Plant Protection and Quarantine) stands shoulder-to-shoulder with citrus growers to combat citrus canker, huanglongbing (HLB … Read More

Canker Quarantine Expanded in Texas

Clint ThompsonCitrus, Diseases, Florida, Top

The U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) announced June 30 it was immediately expanding the area quarantined for citrus canker in Texas. The agency added portions of Cameron County near San Benito and Brownsville to prevent the spread of the disease. APHIS confirmed the positive identification of citrus canker in two residential trees in San … Read More

Nursery Diseases at Planting: What to Watch for

Tacy CalliesDiseases, nursery

By Ozgur Batuman and Megan Dewdney Citrus nurseries work very hard and put forth considerable effort to reduce pest and disease problems. However, there continues to be problems with certain diseases, because the nursery environment for growing citrus trees is ideal for many pests and diseases. Basic principles of good nursery sanitation practices together with screening and removing suspected or … Read More

Citrus Canker Management Through the Year

Ernie NeffDiseases

Plant pathologist Megan Dewdney with the University of Florida Institute of Food and Agricultural Sciences offers suggestions for managing citrus canker at different times of the year. She is an associate professor at the Citrus Research and Education Center (CREC) in Lake Alfred. Dewdney suggests that copper sprays begin when fruit reach three-eighths of an inch in diameter in groves … Read More

Algal Spot: A Re-emerging Disease

Tacy CalliesDiseases

By Megan M. Dewdney Algal spot has not been seen frequently for many years, but in the last few years I have been getting more questions about identification and management. The disease is caused by a green alga, Cephaleuros virescens. The alga is not considered a parasite, as it grows superficially, but it does cause damage to trees if left … Read More

Citrus Leprosis Poses a Threat to Florida

Tacy CalliesDiseases

By Amit Levy, Ozgur Batuman, Peggy Sieburth and Lauren Diepenbrock Citrus leprosis is an exotic viral disease not currently present in Florida. This disease is of interest since it was reported in citrus in Florida and Brazil in the early 1900s, where it caused great crop and tree losses, but it was eliminated from Florida in the early 1960s. Currently, … Read More

Planning for Foliar Disease Management in 2020

Tacy CalliesDiseases

By Megan Dewdney and Evan Johnson In 2019, the trend of fewer problems with foliar fungal diseases for Florida citrus continued, which was good news for the industry. Despite the El Niño conditions during the spring, little postbloom fruit drop (PFD) was observed because the temperatures were low (< 75 F) when it rained during bloom. The southern parts of … Read More

Homeowners Oppose Stay in Citrus Tree Battle

Daniel CooperDiseases, Legislative


(NSF) — Attorneys for Lee County homeowners urged the Florida Supreme Court on Monday to reject the state’s request for a stay in a long-running legal battle about compensating residents for healthy citrus trees cut down amid an effort to halt the spread of citrus canker disease. The Florida Department of Agriculture and Consumer Services last week asked the Supreme Court to put the … Read More

Citrus Black Spot Quarantine Area Updated in Florida

Daniel CooperDiseases, Industry News Release


Effective immediately, the Animal and Plant Health Inspection Service (APHIS) is adding eight sections in Charlotte County, nine sections in Lee County, 28 sections in Hendry County, and five sections in Collier County to the citrus black spot (CBS) quarantine area in Florida. This action is in response to the confirmation of CBS during annual surveys conducted by APHIS and … Read More

FDOC Response to Cancer Study

Daniel CooperCitrus, Diseases, Industry News Release, Research

orange juice

A new study suggesting a link between sugary drink consumption, including 100% fruit juice, and increased cancer risk was recently published in a medical journal. The study has spurred a series of news media stories. Researchers of the study, who are based in France, assessed the associations between the consumption of sugary drinks (sugar sweetened beverages and 100% fruit juices), … Read More

Studying Citrus Greening with an Integrated Approach

Daniel CooperCitrus Greening, Diseases, HLB Management, Industry News Release, Psyllids, Research

citrus greening

While citrus growers continue to look for best management approaches to deal with the deadly greening disease, scientists will take an integrated look at how to protect young trees by using existing tools growers can use. Five scientists from the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) will compare insect management tools, including insect-proof netting. Researchers also … Read More

An Important Reminder on Citrus Tristeza Virus

Tacy CalliesDiseases

By Amit Levy and Ozgur Batuman Citrus tristeza virus (CTV) is an important citrus pathogen that, in the past, had a dramatic effect on the citrus industry and caused the loss of almost 100 million trees worldwide. These trees were propagated on sour orange rootstock. The disease created a need for tristeza-tolerant rootstocks to sustain the citrus industry, because only … Read More

Citrus Black Spot Update

Ernie Neffblack spot, Diseases

Callie Walker with the Florida Department of Agriculture and Consumer Services (FDACS) recently gave an update on the citrus black spot quarantine in Southwest Florida. Walker is bureau chief of pest eradication and control for FDACS’ Division of Plant Industry and serves as statewide director for the Citrus Health Response Program. She summarizes the presentation she made at the Florida … Read More

Hurricane Irma Raises Black Spot Threat

Ernie Neffblack spot, Diseases


University of Florida Institute of Food and Agricultural Sciences Extension pathologist and associate professor Megan Dewdney reported that U.S. Department of Agriculture (USDA) scientist Tim Gottwald thinks there’s a “fairly high” chance that Hurricane Irma spread citrus black spot. Black spot had been confined primarily to Southwest Florida, especially Collier and Hendry counties, before Irma hit the state with damaging … Read More