By Taylor Livingston and Tripti Vashisth Preharvest fruit drop is a major concern for Florida citrus growers, especially in groves affected by huanglongbing (HLB). Environmental stressors such as drought, flooding and cold snaps further accelerate fruit drop and tree decline. Recent field trials in Central Florida evaluated the use of plant growth regulators (PGRs) — specifically gibberellic acid (GA3) and …
Taking a Closer Look at CRISPR in Citrus Breeding
By Manjul Dutt Editor’s Note: This is the second article in a series outlining how genetic technology can be using in citrus breeding. Traditional methods for improving citrus, such as crossbreeding different varieties, can be time-consuming due to the creation of a random mix of genes from both parents through a process called genetic introgression. In the article last month, …
NuCitrus Shows Strong HLB Tolerance
University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) researchers are putting genes from a non-citrus plant into Hamlin oranges to develop citrus plants that fight huanglongbing (HLB), also known as citrus greening disease. The newly developed plant is called NuCitrus. It’s based on a protein called Arabidopsis NPR1 (AtNPR1). The new citrus shows strong tolerance to HLB, but not …
All In For Citrus Podcast, October 2025
The October All In For Citrus podcast features citrus under protective screen (CUPS). Over the past decade, the practice has grown in popularity due to its ability to exclude the Asian citrus psyllid and huanglongbing (HLB) disease. Roughly 1,500 acres of citrus are grown under screen in Florida with more acreage under development. Lauren Diepenbrock, associate professor of entomology at …
Prolong Tree Health by Combining Covers and Brassinosteroids
As every Florida citrus grower knows, it has been difficult to grow trees and fruit profitably since huanglongbing (HLB) disease was discovered in the state in 2005. Soon after the disease was discovered, officials determined it couldn’t be eradicated largely because the Asian citrus psyllids (ACP) that spread it showed up years earlier and were in virtually all citrus-producing regions. …
Improving Citrus Using Genetic Tools
By Manjul Dutt Editor’s Note: This is the first in a series of two articles on plant improvement. Next month will feature the timeline for CRISPR-developed trees. Traditional methods for improving citrus, such as crossbreeding different varieties, can be time-consuming due to the creation of a random mix of genes from both parents through a process called genetic introgression, leading …
Plant Diagnostic Facilities for Georgia Citrus Growers
The University of Georgia (UGA) has disease labs and clinics to help citrus producers determine what diseases are impacting their trees. Jonathan Oliver, UGA assistant professor and small fruits pathologist, highlights the diagnostic facilities that growers can take advantage of. “We have a lab in Tifton, the Plant Disease Clinic, that can accept samples from commercial citrus,” Oliver said. “We …
Influence of Rootstock and OTC Injection on Valencia Yield
By Kim D. Bowman, Ute Albrecht and Caroline Tardivo Profitability of citrus in Florida has been severely reduced by the impact of huanglongbing disease (HLB). Previous studies have demonstrated that rootstock selection and injection of established trees with oxytetracycline hydrochloride (OTC) can both significantly improve the health, cropping and fruit quality of trees affected by HLB. However, neither a superior …
California HLB Quarantine Area Expanded
Federal and state officials recently expanded the area quarantined for citrus greening disease, also known as huanglongbing or HLB, in California. They expanded the quarantined area in the San Clemente area of Orange and San Diego counties by 81 square miles. The action was taken by the U.S. Department of Agriculture Animal and Plant Health Inspection Service (APHIS) in cooperation …
Psyllids and HLB Spreading in Georgia
Populations of Asian citrus psyllids (ACP) have been found in residential and commercial citrus in Georgia’s Lowndes and Wayne counties during the past two months. ACP spread huanglongbing (HLB) disease. In several places where ACP were found, HLB-infected trees were identified nearby. University of Georgia College of Agricultural and Environmental Sciences (UGA CAES) entomologist Apurba Barman provided details about the …
A Bright Future and New Normal for Citrus
Citrus has a brighter future in Florida and surrounding areas, according to one industry expert. Hopefully, there will be enough farmers left standing to profit from it. Rick Dantzler, Citrus Research and Development Foundation chief operating officer, was a featured speaker at this year’s Citrus & Specialty Crop Expo. He spoke about the industry’s future as it continues to navigate …
Save the Orange Initiative Aims to Address HLB
Invaio Sciences, The Coca-Cola Company, MIT (Massachusetts Institute of Technology) Solve and Fundecitrus are participating in the Save the Orange initiative. The collaborative effort aims to address citrus greening disease, also known as huanglongbing (HLB). “We bring to the Save the Orange initiative a powerful suite of innovations, including our commercially available Trecise technology,” Invaio stated. According to Invaio, Trecise is …
Florida Residents Educated About HLB
Residential trees — where citrus greening disease (also known as huanglongbing or HLB) was first detected in the Florida — can serve as reservoirs for disease-spreading Asian citrus psyllids (ACP) if the pests are not properly managed. Recognizing that disease prevention is a coordinated effort, the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) is teaching Florida residents …
Managing Psyllids in Groves and Protected Structures
By Jawwad A. Qureshi The impact of the Asian citrus psyllid continues to intensify through devastation of its vectored huanglongbing (HLB) disease. Although there is no permanent solution for HLB yet, psyllid suppression reduces its impact. Chemical control is the most implemented method. Its strategic use helps reduce psyllid resistance and collateral damage to non-target organisms, including beneficial organisms needed …
The Potential of Trunk Injection for Fresh Market Citrus
By John M. Chater Citrus tree trunk injection of antibiotics has been recently and widely used in Florida. The success of oxytetracycline (OTC) in sweet orange to mitigate huanglongbing (HLB or citrus greening) disease has been documented by the laboratory of Ute Albrecht, associate professor at the University of Florida. Some results suggest that OTC injection can improve Brix, ratio, …
Recommendations for Oxytetracycline Injections
Three University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) researchers recently issued the document Suggested Use Pattern of Injectable Antimicrobials for Huanglongbing (HLB) Management. The authors are Ute Albrecht, associate professor of horticulture; Ozgur Batuman, associate professor of plant pathology; and Megan Dewdney, associate professor of plant pathology. The antimicrobials for Florida citrus are ReMedium TI and Rectify; …
HLB in Brazil: Focus on Psyllid Control
Fundecitrus researcher Renato Bassanezi recently emphasized the importance of controlling the psyllid that spreads huanglongbing (HLB, also known as citrus greening) in Brazil. Bassanezi pointed out that with the increase of HLB-spreading psyllids recorded in 2023 and the lack of eradication of diseased trees, controlling the HLB-spreading insect becomes increasingly important. The researcher said there can be no failures in …
California HLB Quarantines Expanded
Federal and state agriculture officials recently expanded the areas quarantined for huanglongbing (HLB, also known as citrus greening) disease in California. The quarantined area in the Foothill Ranch and Mission Viejo areas of Orange County has been expanded by 26.69 square miles, the Riverside area of Riverside County by 11.3 square miles, and the Valley Center area of San Diego …
IPCs Provide Citrus Trees a ‘Fighting Chance’
Citrus Research and Development Foundation President Morgan McKenna Porter said individual protective covers (IPCs) give newly planted trees a “fighting chance” against huanglongbing (HLB) and serve as a bridge until HLB-resistant trees are available. “IPCs are not flawless, but they certainly can be optimized,” Porter said. “I have the ability to plant a young tree and put an IPC over …
Trunk-Injection Biopesticide for HLB
Ching-Hong Yang, University of Wisconsin-Milwaukee (UWM) biological sciences professor, was recently awarded a $1.5 million federal grant to support research on a compound that suppresses HLB disease. His project is titled Bringing RejuAgro to Market: Development of a Groundbreaking Trunk Injection Biopesticide for Huanglongbing (HLB). The grant is from the U.S. Department of Agriculture National Institute of Food and Agriculture …





























