Citrus researchers at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) are taking a more comprehensive look at how tools to manage HLB affect young trees. The goal is to develop integrated approaches and update management practices for growers. After one year of the research project, some interesting results are already emerging. The research project, “Establishing Healthy …
Updating Guidelines for New Plantings
Researchers at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) are taking a whole-systems approach to update current recommendations for new plantings. A research project, “Establishing Healthy Citrus Plantings in the Face of Persistent HLB Pressure,” is led by UF/IFAS entomologist Lauren Diepenbrock. According to Diepenbrock, current guidelines were created pre-HLB and therefore are out of date …
All In For Citrus Podcast, April 2021
A whole-systems approach to one University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) research project is the focus of the April All in For Citrus podcast. Citrus Research and Education Center Director Michael Rogers said the project is a good example of citrus researchers taking a more comprehensive look at problems in the industry. “We’re starting to put …
Plan Greasy Spot and Melanose Management
By Megan Dewdney Greasy spot and melanose are two fungal diseases that have long needed the attention of Florida citrus growers. While they are more of a concern for fresh fruit growers, trees for processing can be damaged, too. In terms of management priorities, greasy spot is the greater concern since it reduces tree photosynthetic capacity and causes defoliation. Melanose …
What to Do About Citrus Black Spot
By Megan Dewdney Citrus black spot is one of the newer diseases to worry Florida citrus growers. The fungal disease was first detected in Southwest Florida in 2010. The vast majority of finds have been in the southwestern citrus-producing counties of Collier, Hardee, Lee, Charlotte and Glades, but the disease has slowly moved northward. Black spot is still considered a …
Minimize Blemishes on Tangerines and Grapefruit
Megan Dewdney Since tangerines and grapefruit they are eaten fresh, a blemish-free peel is highly desired. Two diseases that frequently mar the peels of tangerines, and occasionally grapefruit, are Alternaria brown spot (ABS) and citrus scab. Both diseases cause symptoms on leaves and fruit. ALTERNARIA BROWN SPOTThe early foliar symptoms of ABS are small yellow flecks that quickly become larger …
Scout Early Bloom for PFD
By Andre B. Gama and Megan M. Dewdney Postbloom fruit drop (PFD) of citrus is a disease caused mostly by the fungus Colletotrichum acutatum. This fungus survives by producing resting structures on leaves and stems. When flowers start to appear in groves, these resting structures produce spores that can cause PFD. However, the fungus requires specific weather conditions to be …
Foliar Disease Management in 2021
By Megan Dewdney There were many challenges in 2020, but fortunately the Florida season for foliar citrus diseases was relatively normal. Little to no postbloom fruit drop (PFD) was reported during the 2020 bloom because of a sudden dry spell as the flowers opened. As spring 2021 approaches, the forecast is for a La Niña weather pattern with slightly warmer …
Time to Cut the Dead Wood
By Megan Dewdney, Tripti Vashisth and Lauren Diepenbrock Dead wood has long been challenging for fresh citrus fruit production. Spores in twigs can form which cause blemishing diseases that downgrade fruit for lower profits. More recently, it has come to light that there are horticultural and entomological reasons to remove this wood as well. Many growers are familiar with melanose, …
Sneak Peek: February 2021 Citrus Industry
While everyone strives to protect themselves from coronavirus disease, growers have an additional concern: protecting their trees from citrus disease. While HLB is of course the most damaging disease of citrus, there are other diseases that should not be overlooked. Disease management is the theme of the February 2021 issue of Citrus Industry magazine. University of Florida Institute of Food …
Citrus Holiday Traditions
By Ruth Borger and Megan Dewdney Oranges and other citrus have a special place during holiday celebrations. We find them in our decorations, on our dinner table, shipped to friends and families across the country, and sometimes, if you are really good, in your Christmas stocking. But where did these traditions come from? And when did they become part of …
Black Spot Likely in More Florida Counties
Although citrus black spot has only been detected in commercial groves in five Southwest Florida counties, it is still spreading and likely to be in additional counties, according to plant pathologist Megan Dewdney. The five counties with detections are Charlotte, Collier, Glades, Hendry and Lee. Dewdney is a University of Florida Institute of Food and Agricultural Sciences associate professor at …
Emerging Trunk Disorders
By Evan Johnson and Megan Dewdney The last two years have seen increasing grower questions and reports of citrus trunk disorders in Florida. Sometimes these reports are associated with sudden tree collapse. In many cases, phytophthora foot rot is initially suspected. Typically, the symptoms don’t quite match those of foot rot, and phytophthora cannot be isolated from the lesion. If …
Citrus Advisory System Provides PFD Alerts
Beep. Beep. Beep. That’s the sound of an alert telling a citrus grower it’s time to spray fungicide to help prevent fruit from falling off the tree due to postbloom fruit drop (PFD). University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) researchers have developed a Citrus Advisory System (CAS) that sends web-based alerts to growers via mobile devices. …
Phosphite Best for Algal Spot
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, …
Black Spot and Production Guide Updates
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 …
All In For Citrus Podcast, September 2020
National recognition, new findings on black spot control, and research on antimicrobial peptides highlight the September episode of the All In For Citrus podcast. Citrus Research and Education Center Director Michael Rogers starts the episode with the announcement that the University of Florida was ranked in the top 10 of U.S. News and World Report’s Top Public Schools list. Rogers …
Gibberellic Acid: Increase Fruit Size and Yield, Reduce Drop
By Tripti Vashisth and Megan Dewdney This article discusses the use of gibberellic acid (GA), the naturally occurring plant hormone, on huanglongbing (HLB)-affected trees. The results were generated from a 3-year trial in which Valencia trees were treated with GA in the fall. The outcomes suggest that GA can be effectively used for synchronizing and suppressing profuse flowering without negatively …
CRDF Looking at Peptide for HLB
When news broke in July that University of California Riverside (UCR) scientists had found a peptide that might control HLB, Rick Dantzler quickly contacted lead UCR scientist Hailing Jin. Dantzler is chief operating officer of the Citrus Research and Development Foundation (CRDF), which was organized in Florida primarily to find ways to solve or cope with HLB. Jin had found …
Canker Quarantine Expanded in Texas
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 …