Native Lime Might Keep HLB Out of Australia

Josh McGillHLB Management, International, Limes

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

Josh McGillHLB Management, Technology, Tip of the Week

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

Josh McGillEvents, HLB Management

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

Josh McGillCRDF, HLB Management, Research

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

Josh McGillHLB Management, Pests

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

Tacy CalliesHLB Management, PGRs, Research

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

Josh McGillHLB Management, PGRs, Tip of the Week

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

Josh McGillHLB Management, International, Research

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

Josh McGillEvents, HLB Management

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

Josh McGillFlorida Department of Citrus, HLB Management, Varieties

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

Josh McGillHLB Management, Research

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

Josh McGillHLB Management, Pesticides

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

Josh McGillHLB Management, International

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

Josh McGillHLB Management, PGRs, Research

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

Josh McGillHLB Management, Tip of the Week

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

Josh McGillBrazil, HLB Management

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 …

Examining Hamlin Survivor Trees

Josh McGillHLB Management, Research, Varieties

By Gary England, Fred Gmitter and Manjul Dutt In 2014, most groves in Central Florida had citrus greening infection rates approaching 100%, but a Lake County grower reported that some trees in his Hamlin on Swingle blocks seemed to be relatively healthy. Some visual HLB symptoms were observed on these “surviving” trees, but they did not have the massive fall …

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Revised Approach to Reduce ACP Management Costs

Josh McGillHLB Management, Tip of the Week

By Lukasz Stelinski Vector control is considered a basic component of HLB management even under high disease incidence scenarios. A recent study compared the effects of three different economic thresholds (ET-0.2, ET-0.5 and ET-1.0) and one calendar-based application schedule on the incidence of Asian citrus psyllid (ACP) and beneficial species in plots of commercially grown citrus. The study also examined …

Sneak Peek: March 2023 Citrus Industry

Josh McGillCRDF, HLB Management, Sneak Peek

The March cover of Citrus Industry magazine features a fresh face in a key industry leadership role for Florida. Morgan McKenna Porter is bringing youthful energy to her new title as president of the Citrus Research and Development Foundation (CRDF) board of directors. In the cover story, learn about her background as well as her CRDF goals for helping growers …

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Why There Is a Lack of HLB in Georgia

Josh McGillGeorgia, HLB Management

HLB has yet to become a major problem for Georgia’s citrus producers. Jonathan Oliver, University of Georgia assistant professor and small fruits pathologist, attributes the disease’s lack of presence in Georgia’s commercial groves to multiple factors. “It still comes down to the fact that, number one, you don’t see symptoms for a while. A lot of our trees are young,” …