By Tripti Vashisth and Mary Sutton Citrus trees affected by huanglongbing (HLB) show significant root dieback. This dieback results in smaller root systems than would be seen in healthy citrus trees. These small root systems are limited in their uptake capacity. In other words, if an HLB-affected tree is given the same amount of water as a healthy tree, the …
HLB and Psyllids in Georgia Commercial Citrus
One of Georgia citrus growers’ worst fears is slowly becoming a reality. Citrus greening, also known as huanglongbing (HLB), was observed in a Georgia commercial citrus grove for the first time in 2023. This is alarming news for the industry, says Jonathan Oliver, University of Georgia (UGA) assistant professor and small fruits pathologist. “We knew HLB was here in residential …
Heat and HLB Hurting Brazil’s Production
Brazil’s citrus crop is suffering this season, according to Franklin Behlau, a senior researcher for Fundecitrus. That was the focus of a recent presentation he provided at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Citrus Research and Education Center in Lake Alfred. “Things have changed in Brazil this season,” Behlau said. “We are a little behind …
HLB Product Advancing in Registration Process
Silvec Biologics announced that an RNA vector delivery product to combat HLB has progressed to the Full Science Review Phase of the Environmental Protection Agency (EPA) Pesticide Regulation Improvement Act registration process. The product was developed in collaboration with Southern Gardens Citrus (a subsidiary of U. S. Sugar), the University of Florida (UF) and Texas A&M AgriLife Research. Silvec is …
Sustaining Citrus Production in the HLB Era
The virtues of daily irrigation and increased micronutrient applications were among key points researcher Davie Kadyampakeni made in an Aug. 13 discussion of citrus production in the HLB era. Kadyampakeni is a University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) associate professor of soil, water and ecosystem sciences at the Citrus Research and Education Center in Lake Alfred. …
New HLB Publication at the Citrus & Specialty Crop Expo
By Michael E. Rogers Do you plan to attend the Citrus & Specialty Crop Expo on Aug. 21–22 at the Florida State Fairgrounds in Tampa? If so, you’ll want to stop by the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Citrus Extension booth to pick up the latest publication on HLB management assembled by UF/IFAS citrus experts. …
Reasons to Believe HLB Is Beatable
Growers gathered in Bonita Springs in mid-June for the Florida Citrus Industry Annual Conference. The event hosted by Florida Citrus Mutual drew a good crowd. The mood of growers was mixed. While there was hope that HLB trunk-injection therapies might have resulted in more dramatic improvements to this year’s crop, there also was recognition that these therapies represent one of …
CUPS Allows Profitable HLB-Free Citrus Production
The U.S. Department of Agriculture National Institute of Food and Agriculture (USDA/NIFA) has invested more than $250 million to find a solution for HLB. One example of USDA NIFA-funded research is citrus under protective screen (CUPS). University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) scientist Arnold Schumann and colleagues began testing CUPS at the Citrus Research and Education Center …
International HLB Conference Focused on Grower Solutions
This spring, the seventh International Research Conference on Huanglongbing (IRCHLB) was held in Riverside, California. The inaugural event was held in 2008 and funded by a grant from the U.S. Department of Agriculture (USDA) National Institute of Food and Agriculture. USDA researcher Tim Gottwald and University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) professor Jim Graham founded the …
Researchers Discuss Rising HLB Incidence in Brazil
The incidence of citrus greening disease (HLB) in Brazil’s Citrus Belt of São Paulo and Triângulo/Southwest Mineiro rose from 24.42% in 2022 to 38.06% in 2023, according to Fundecitrus. The association’s annual survey indicates the disease increasingly demands more effective and collaborative measures. At a session of Brazil’s Expocitrus in June, Fundecitrus researcher Marcelo Miranda discussed the development of greening …
Study Shows Florida Residents’ Attitudes on HLB
In the fall of 2022, five University of Florida researchers investigated Florida residents’ attitudes on HLB and Asian citrus psyllids (ACP) using online surveys over a 9-month period. The results of the study, Residents’ contribution to Asian citrus psyllid and citrus greening management in Florida residential habitats, was recently published in the Journal of Integrated Pest Management. Authors Romain Exilien, …
Study Sheds Light on Defense Against HLB-Spreading Psyllids
A study by researchers from the Guangdong Academy of Agricultural Sciences and South China Agricultural University sheds light on the genetic mechanisms that can defend against Asian citrus psyllid (ACP) infestation. ACP is the vector for HLB, the most devastating disease of citrus. The study was published in Horticulture Research on April 1. It unveils the roles of two cytochrome …
Survivor Grapefruit Cultivars Set for HLB Trials
The U.S. Department of Agriculture Agricultural Research Service (USDA-ARS) citrus scion breeding program recently rediscovered several noteworthy grapefruit cultivars at the A.H. Whitmore Foundation Farm in Groveland, Florida. Among these are the Florida Red, Red Blush and Henderson varieties. These cultivars were originally selected as long shots from the Whitmore Foundation Farm and were planted in 1986. They have survived …
Cover Crops for Managing HLB
By Davie Kadyampakeni and Miurel Brewer Row middle management is a key area that can improve tree performance. Row middles encompass 80% of citrus orchards, and 70% of the root system of citrus trees was located in row middles before huanglongbing (HLB). Typically, Florida citrus growers manage row middles using physical, chemical and mowing practices, often leaving them free of …
Some Grapefruit Showing Less HLB Symptoms
A recent update of the U.S. Department of Agriculture Multi-Agency Coordination (MAC) Project evaluating multiple grapefruit varieties on different rootstocks reveals that some combinations have less HLB symptoms than others. Jackson has one of the lowest ranks for disease index across the combinations. The healthiest trees in the trial include: At least half of the blocks in the MAC trial …
Interstock Pros and Cons for HLB Management
The pros of using interstocks for HLB management seemed to outweigh the cons, based on a presentation horticulturist Manjul Dutt made at this spring’s Florida Citrus Growers’ Institute. Dutt is a University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) assistant professor. An interstock is a graft of a citrus selection that can be used as a bridge between …
Texas Researcher Honored for HLB Work
Texas A&M researcher Kranthi Mandadi has received the 2024 American Phytopathological Society (APS) Syngenta Award given to select scientists working in areas of crop protection and plant pathology. Mandadi is an associate professor in the Department of Plant Pathology and Microbiology at the Texas A&M AgriLife Research and Extension Center at Weslaco. He was selected for the award primarily for his breakthrough research on fastidious, …
CRDF Focused on the Search for HLB Resistance
According to Rick Dantzler, Citrus Research and Development Foundation (CRDF) chief operating officer, the past seven days have been busy for CRDF’s committees. First, the Plant Improvement Committee, chaired by grower Joby Sherrod, reviewed several projects and ideas seeking HLB resistance in detail. A three-year plan for the plant improvement programs for University of Florida Institute of Food and Agricultural …
‘Crucial Step’ Taken in HLB Bacterium Cultivation
Huanglongbing (HLB) is caused by the bacterium Candidatus Liberibacter asiaticus (CLas), which has been challenging to culture outside its host because of its intracellular nature and genome reduction. Due to these challenges, in-depth research on effective cultivation methods for CLas is essential to develop better control strategies. Such in-depth research was conducted by a team from the U.S. Department of …
Phytophthora Increasing; HLB Complicates Control
Phytophthora incidences are increasing in Florida citrus groves, plant pathologist Ozgur Batuman reported during a May 21 presentation. Phytophthora diseases include foot rot of trunk and limbs, root rot and brown rot. Batuman, a University of Florida Institute of Food and Agricultural Sciences associate professor, said these diseases led to yield reductions of 3% to 6% per year even prior …