What To Do About Algal Spot

Tacy CalliesDiseases, Tip of the Week

By Megan Dewdney I did not need to visit my field trial to know that algal spot was in bloom on citrus in the last month. I have received many phone calls about it recently as growers notice the bright orange doughnuts on their tree limbs. For those unfamiliar with algal spot, it is a disease that occurs mostly on …

Understanding Physiological Fruit Drop of Citrus

Tacy CalliesFruit Drop, Tip of the Week

By Tripti Vashisth, Megan Dewdney and Lauren Diepenbrock Citrus flowers profusely, but less than 2% of the flowers become harvestable fruit. In other words, 98% of the flowers seen during bloom will end up on the grove floor at some point during fruit development, whether as a flower, fruitlet, young fruit or mature fruit. Profuse flowering allows trees to produce …

Effects of Grower Tools on Citrus Diseases and Roots

Ashley RobinsonDiseases, Root health

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 …

new grove

Updating Guidelines for New Plantings

Ashley RobinsonAll In For Citrus Podcast, HLB Management, Research

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 According to Diepenbrock, current guidelines were created pre-HLB and therefore are out of date …

citrus

All In For Citrus Podcast, April 2021

Taylor HillmanAll In For Citrus Podcast, Sponsored Content

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

Tacy CalliesDiseases, Tip of the Week

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 …

citrus black spot

What to Do About Citrus Black Spot

Tacy CalliesDiseases, Tip of the Week

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

Tacy CalliesDiseases, Tip of the Week

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

Tacy CalliesCitrus, Diseases, Tip of the Week

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

Tacy CalliesDiseases

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

Tacy CalliesTip of the Week

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

Tacy CalliesDiseases, Sneak Peek

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

Tacy CalliesTip of the Week

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 …

aphis

Black Spot Likely in More Florida Counties

Ernie NeffDiseases

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

Tacy CalliesDiseases

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

Ernie NeffDiseases

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

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, …

citrus black spot

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 …

citrus

All In For Citrus Podcast, September 2020

Taylor HillmanAll In For Citrus Podcast, Sponsored Content

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

Tacy CalliesProduction

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 …