Entomologist Kirsten Pelz-Stelinski recently shared findings from trials on the use of foliar-applied and trunk-injected antibiotics for controlling HLB and the Asian citrus psyllids (ACP) that spread the disease. Pelz-Stelinski is associate center director at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Citrus Research and Education Center (CREC) in Lake Alfred. In a May 17 presentation …
HLB in Florida Is a Warning to California
The damage that HLB has inflicted on Florida citrus groves and production over the past 18 years should serve as a warning for California producers, California’s Citrus Pest & Disease Prevention Program (CPDPP) stated recently. CPDPP noted that with HLB detected in thousands of California residential trees, it’s important for commercial growers to take steps to prevent the disease. According …
Repurposing Tools to Tackle HLB
By J. Scott Angle, jangle@ufl.edu, @IFAS_VP The hurricane-battered harvest numbers don’t show it, but we’re in a much better place in developing scientific solutions for managing HLB than we were a year ago. That’s because our scientists have discovered that tools invented to solve other problems can help address your one big problem. GIBBERELLIC ACIDFor example, gibberellic acid (GA) has …
Awareness Campaign Battles HLB in Brazil
Brazil’s Fundecitrus in 2022 and 2023 conducted an awareness campaign to replace citrus and myrtle plants to combat HLB in the municipality of Itobi, São Paulo. The citrus and myrtle plants were replaced with other fruit and ornamental species that do not host the Asian citrus psyllid that transmits HLB, also known as greening disease. These citrus and myrtle plants …
Native Lime Might Keep HLB Out of Australia
A comprehensive map of the genome of an Australian native lime species that is resistant to HLB could be the key to preventing the disease from entering Australia. Researchers from The University of Queensland (UQ) in Australia have sequenced the genome of the Australian round lime, also known as the Gympie lime. They are now looking at five other native …
Determine Tree Health With Canopy Assist
By Amit Levy and Tripti Vashisth Many Florida citrus growers are currently injecting oxytetracycline, spraying gibberellic acid (GA) or treating trees with enhanced nutrition. A new program offered by the University of Florida Institute of Food and Agricultural Sciences (UFIFAS) Citrus Research and Education Center (CREC) can help growers determine if these treatments are improving tree health and leading to …
Growers Share First Impressions of Trunk Injection
The Peace River Valley Citrus Growers Association (PRVCGA) hosted growers and industry members on National Orange Juice Day to discuss early experiences with trunk injection of oxytetracycline hydrochloride (OTC-HCl). Two new OTC-HCl products, ReMedium TI and Rectify, were registered this season for use as an HLB treatment in Florida citrus. While some growers are taking a wait-and-see approach to trunk …
Exploring Additional Antimicrobials for Citrus Injection
The Citrus Research and Development Foundation (CRDF) board of directors invited six full proposals on combining other antimicrobials with oxytetracycline hydrochloride (OTC-HCl) during its April meeting. “If growers are going to pay the labor costs for workers to crawl underneath a citrus tree to treat it with OTC-HCl, maybe there are other things that could be mixed with the injection,” …
New Twist Added to Psyllid Control
Lukasz Stelinski for years has promoted saving money on HLB control by spraying for Asian citrus psyllids (ACP) only when their populations reach a certain threshold. The University of Florida Institute of Food and Agricultural Sciences professor still promotes that concept, but with a slightly new twist. TRUNK INJECTION SHOWING PROMISEIn a virtual seminar on April 25, Stelinski advised growers …
Cytokinin Studied for Citrus Health Benefits
Tripti Vashisth, University of Florida Institute of Food and Agricultural Sciences associate professor, has been leading the research on how plant growth regulators (PGRs) can improve the health of HLB-infected trees. She’s conducted extensive research on the use of gibberellic acid. But she has recently begun to study another hormone, cytokinin. She gave an update on this work during the …
Gibberellic Acid Applications: Day vs. Night
By Alessandro Franco, Faisal Shahzad and Tripti Vashisth Gibberellic acid (GA) is one of the most commonly used plant growth regulators which affects flowering, fruit and vegetative growth. Multiple monthly GA foliar applications have reduced preharvest fruit drop and increased yield in huanglongbing (HLB)-affected sweet oranges. The potential impact of these findings is huge for commercial citrus production. However, there …
Project Seeks Quick HLB Diagnostic Tests
Canadian college Seneca, in partnership with Ottawa-based Evik Diagnostic Innovations Inc., is working to develop a quick diagnostic test for the citrus disease HLB. Frank Merante, professor in Seneca’s School of Biological Sciences & Applied Chemistry, is the principal investigator for the project. The idea behind the research was to develop a simple way for growers to test crops and identify the …
Trunk Injection Inspires Interest in Planting
The Florida Citrus Growers’ Institute, presented by the University of Florida Institute of Food and Agricultural Sciences, was held in Avon Park on April 4. The annual educational event drew a good crowd of growers and allied industry. After nearly two decades of fighting HLB, and more recently fallout from hurricanes, those in attendance expressed a renewed sense of optimism …
Update on HLB-Tolerant/Resistant Tree Programs
The Florida Citrus Commission (FCC) in March heard updates on programs intended to provide growers with HLB-tolerant or -resistant trees and on other Florida Department of Citrus (FDOC) scientific research programs. Director of Scientific Research Rosa Walsh provided the updates. The FCC serves as the FDOC’s governing board. Walsh announced that for the FDOC’s Program for Expedited Propagation, all materials …
Lessons Learned From HLB as an Immune-Mediated Plant Disease
By Nian Wang How the huanglongbing (HLB) pathogen Candidatus Liberibacter asiaticus (CLas) causes damage to infected citrus trees has been widely debated. A recent study demonstrates that HLB is an immune-mediated plant disease (Ma et al., 2022). It was discovered that CLas infection of citrus stimulates systemic and chronic immune response in phloem tissues, including reactive oxygen species (ROS) production, …
Citrus Agent Discusses Oxytetracycline Hydrochloride Products
University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) multi-county citrus Extension agent Ajia Paolillo recently provided information about two commercial oxytetracycline hydrochloride products approved for use against HLB. TJ Biotech LLC was the first company to receive approval from the Environmental Protection Agency (EPA) for trunk injection of this formulation. EPA granted TJ Biotech a Federal Insecticide, Fungicide, …
Uruguay Has First HLB Detections
The first cases of plants with HLB disease have been confirmed in Uruguay, according to a health emergency note released by the country’s Ministry of Livestock, Agriculture and Fisheries. Plants with symptoms were found in a residence in the city of Bella Unión. After laboratory analysis, the presence of the disease was confirmed. Inspections were carried out in the homes …
Gibberellic Acid Shows Promising Results on Hamlin
By Tripti Vashisth and Taylor Livingston Grower-led trials in 2022 showed positive results of gibberellic acid (GA) treatment on Hamlin trees in Florida. This article primarily discusses two growers’ trials in detail. Both sites showed improvement in fruit production from the GA application. Many growers have adopted GA applications in the past year as part of their grove management strategy. …
Top 10 Best Practices for Trunk Injection
By Ute Albrecht Replicated field studies have demonstrated positive effects of oxytetracycline administered by trunk injection to manage HLB. In October 2022, a 24(c) special local need label was approved that allows the use of this technology in Florida, and final clearance was given in January. When practicing trunk injection, it is important to do so properly and to be …
HLB Concerns Government Officials in Brazil
Brazil’s Fundecitrus on Feb. 15 participated in a meeting with state and local government representatives to discuss the country’s citrus greening (HLB) situation. Representatives of the Department of Agriculture and Supply (SAA) of the state of São Paulo and mayors of some municipalities in the citrus belt also attended. Mayors and representatives of city halls expressed concern about the economic …