Uncovering the Cause of Greasy-Green on Grapefruit 

Josh McGill Grapefruit, Tip of the Week

By Megan Dewdney, Mark A. Ritenour and Liliana M. Cano  In the last few years, 89% of Florida grapefruit growers have struggled with a disorder that they refer to as greasy-green, leading to losses between $20,000 to $1.7 million per year. The disorder causes the fruit to have large, diffuse green patches on the rind after degreening, making it no …

Improve Fruit Yields and Juice Quality

Josh McGill Nutrition, Pest Management, Tip of the Week

By Davie Kadyampakeni and Megan Dewdney The University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) conducted a six-year project to determine if plant nutritional fertilizer sources coupled with specific crop protection chemicals help mitigate citrus diseases. This project was conducted on a 5-acre commercial citrus grove block near the Citrus Research and Education Center (CREC) in Lake Alfred. …

HLB Tools for Today and Tomorrow

Josh McGill Citrus Expo, HLB Management

By Frank Giles and Tacy Callies The Citrus & Specialty Crop Expo hosted two citrus educational sessions during the Aug. 16–17 event held at the Florida State Fairgrounds in Tampa. The sessions included both long-term research aimed at delivering trees resistant to HLB as well as what growers can do today to help mitigate the effects of the disease in …

Brown Rot Could Be on the Horizon for Florida

Josh McGill Diseases, Tip of the Week

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 …

Connecting Research for Better HLB Management Results

Josh McGill HLB Management, Research, Tip of the Week

By Megan Dewdney To make informed management decisions, growers need to know about and understand the findings from huanglongbing (HLB) research that are currently available. However, the delivery of research results to growers is often fragmented, and results can be difficult to find. Furthermore, what information and conclusions are available to growers from projects or scientific journals can be highly …

Greasy-Green Research Update

Josh McGill Diseases, Research

University of Florida Institute of Food and Agricultural Sciences researchers Megan Dewdney, Mark Ritenour, Liliana Cano, Eva Mulandesa and Monty Myers recently provided an update of their greasy-green disorder research. Excerpts follow from the Indian River Citrus League’s River Ramblings publication: “Greasy green” is a term applied to fruit that develop what appears to be greasy spot rind blotch symptoms …

Citrus Black Spot Spreads in Polk County

Josh McGill Diseases

Citrus black spot (CBS) disease was confirmed at a second location in Florida’s Polk County in March. The new find was in a grove near State Road 60 and Indian Lake Estates, east of Lake Wales. The only prior CBS infestation in Polk County was near U.S. 27 on the Highlands County border. But that location was turned into an …

Citrus Research Funding Update

Josh McGill Research

During the recent Florida Citrus Growers’ Institute, Michael Rogers, director of the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Citrus Research and Education Center, provided details on recently funded citrus research projects. “The $16.3 million (from the U.S. Department of Agriculture) will go toward new research or continuing research to keep promising projects going,” Rogers said.  Eight …

New Plantings a Focus of Phytophthora Management

Josh McGill Diseases

Plant pathologist Megan Dewdney put emphasis on new plantings during a mid-March discussion of phytophthora management for citrus trees infected with HLB. Dewdney is a University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) associate professor at the Citrus Research and Education Center, where she spoke. Dewdney’s presentation was part of an OJ break hosted by UF/IFAS Extension multi-county …

Post-hurricane Expectations for Foliar Diseases and Phytophthora

Josh McGill Diseases, hurricane

By Megan Dewdney For foliar diseases, 2022 started off easily with limited outbreaks in Florida because the spring was dryer than average. The same La Niña weather pattern responsible for the dry conditions of the last two springs is predicted to occur again this winter into early spring. The weather pattern is then predicted to become a neutral pattern with …

Prepare for the Possibility of Postbloom Fruit Drop 

Josh McGill Diseases, Tip of the Week

By Megan M. Dewdney Postbloom fruit drop (PFD) is a sporadic flower disease. It is primarily caused by the fungus Colletotrichum acutatum. While infections only occur on flowers, the fungus is present on trees throughout the year. It survives by producing resting structures on leaves and stems. How the inoculum survives multiple years between infections is still unclear. The fungus …

Considerations for Managing Citrus Black Spot

Josh McGill Diseases

In Florida, citrus black spot (CBS) is present primarily in commercial groves in five southwest counties (Charlotte, Collier, Glades, Hendry and Lee). The disease can cause up to 60% yield loss in severe situations with little management, researcher Megan Dewdney reported in January. More commonly though, growers with infestations experience fruit drop levels of 10% to 20% in a minimally …

Sneak Peek: February 2023 Citrus Industry

Josh McGill Diseases, Sneak Peek, weeds

With more growers incorporating compost and organic amendments into their production, weed management is receiving increased attention. University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) authors Ramdas Kanissery and Mahesh Bashyal take on this topic in their article in the February 2023 issue of Citrus Industry magazine. While compost and organic amendments can increase soil health and boost …

Updates on Florida Citrus Diseases

Josh McGill Diseases

Researcher Megan Dewdney recently provided updates on citrus canker, postbloom fruit drop (PFD) and algal spot. Dewdney is a University of Florida Institute of Food and Agricultural Sciences associate professor of plant pathology at the Citrus Research and Education Center. CANKERFruit is most susceptible to canker when it is from 3/8 to 1.5 inches in diameter, Dewdney said. The fruit’s …

$21.7 Million for HLB Research

Josh McGill HLB Management, Research

Seven entities recently received $21.7 million to conduct research into combating and preventing HLB at the farm level. The funding is from the U.S. Department of Agriculture’s National Institute of Food and Agriculture (USDA NIFA) Emergency Citrus Disease Research and Extension program. The University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) received the majority of the funding, more …

Post-Hurricane Disease Management Advice

Josh McGill All In For Citrus Podcast, Diseases

Megan Dewdney, associate professor of plant pathology with the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS), joined the October All In For Citrus podcast to discuss Hurricane Ian and tips on disease management after the storm. Hurricanes weaken citrus trees and spread disease.  “If a tree has a full canopy, the wind will put a lot of …

Phytophthora Treatments for Hurricane-Damaged Groves

Josh McGill Diseases, hurricane, Tip of the Week

By Megan Dewdney A priority for the Florida citrus industry is evaluating groves for damage and determining the best course of action going forward after the destruction of Hurricane Ian. One of the many considerations is the effect of flooding on root health, particularly if standing water has remained longer than 72 hours. The main diseases are phytophthora foot, crown …

All In For Citrus Podcast, October 2022

Josh McGill All In For Citrus Podcast, hurricane

The October All In For Citrus podcast focuses on Hurricane Ian and its impact on the state’s signature crop. The storm tore a path across Florida’s citrus-growing regions, causing hundreds of millions of dollars in damage. Michael Rogers, director of the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Citrus Research and Education Center, provides details on how …

How Different Techniques Hold Up to Diseases

Josh McGill Citrus Expo, Diseases, IPCs

How well reflective mulch, kaolin clay and individual protective covers (IPCs) hold up to HLB, canker and greasy spot diseases was researcher Megan Dewdney’s topic at the 2022 Citrus & Specialty Crop Expo. Dewdney is a University of Florida Institute of Food and Agricultural Sciences associate professor of plant pathology at the Citrus Research and Education Center.  The research project …