University of Florida Institute of Food and Agricultural Sciences researcher Jude Grosser discusses small experiments that indicated manganese and boron can help citrus trees cope with HLB. In a greenhouse experiment from a few years ago, HLB-infected sweet orange trees were overdosed with micronutrients and secondary nutrients. “It looked like … manganese had the biggest effect on growth of the …
Zinkicide Could Help Manage HLB
University of Florida Institute of Food and Agricultural Sciences researcher Evan Johnson reports that the product Zinkicide appears promising as a management tool for HLB. “Zinkicide is a zinc-based nanoparticle that is designed to become systemic inside the tree and has high bactericidal activity so that hopefully it can target Liberibacter,” Johnson says. Liberibacter is the causal agent of HLB. …
Rucks on Citrus Varieties and Industry Recovery
Phil Rucks of Phillip Rucks Citrus Nursery weighs in on the increasing demand for late versus early orange varieties, the impact of Hurricane Irma and HLB. Rucks notes that over the past 30 years, the demand for early-season oranges versus late-season oranges has essentially reversed. In the past, he says, early varieties accounted for about 60 percent of plantings. Now, …
For Psyllids, Kaolin Clay Beats Foliar Insecticides
University of Florida Institute of Food and Agricultural Sciences researcher Christopher Vincent says kaolin clay outperforms foliar insecticides for management of HLB-spreading psyllids at times when kaolin’s use is practical. His presentation on the topic followed the Citrus Research and Development Foundation (CRDF) meeting on May 22 at the Citrus Research and Education Center in Lake Alfred. The presentation, part …
Citrus Greening, CRDF and the National Academy of Sciences
Citrus Research and Development Foundation (CRDF) Vice President and Governance Committee Chairman Rick Kress comments on a recent National Academy of Sciences (NAS) report regarding HLB and CRDF. He says NAS reported that CRDF has pursued all angles on HLB, also known as citrus greening, and declared there won’t be a single solution or cure. When NAS worked with CRDF …
Researchers Find How HLB Bypasses Citrus Immune System
Researchers at the University of California, Riverside (UCR) claim they have made an important step in understanding the molecular mechanism of huanglongbing (HLB). They believe they have found the mechanism by which the disease evades detection and destruction by the natural immune system of citrus trees. HLB, or citrus greening disease, has devastated groves in Asia, South America and the …
HLB-Tolerant Interstocks
The use of highly HLB-tolerant genotypes as interstocks on a tree with a Swingle rootstock and a Valencia scion infected with HLB is offering hope for help against HLB, Jude Grosser reports. Grosser is a plant breeder with the University of Florida Institute of Food and Agricultural Sciences at the Citrus Research and Education Center in Lake Alfred. “Virtually every …
CRDF Focuses on HLB Research Communication
The Citrus Research and Development Foundation’s (CRDF) board of directors, which is focused on HLB, discussed ways to improve communications with growers and others during a meeting in Immokalee on Tuesday. The directors asked numerous growers attending the meeting at the Southwest Florida Research and Education Center for their input regarding improved communication. One grower said he needs more detail …
Grower Discusses HLB Management Strategies
Jim Snively, vice president of grove operations at Southern Gardens Citrus, discusses his company’s management of HLB and the psyllids that spread it. He summarizes a presentation he made at the International Citrus Business Conference in March. “By reducing stress, the trees can deal with disease much better,” Snively says. “We’re doing this through continuous-type feeding or frequent feeding with …
Imidacloprid Alternatives for Psyllid Control
Phil Stansly, University of Florida Institute of Food and Agricultural Sciences entomologist, discusses alternatives to imidacloprid for helping to control HLB-spreading Asian citrus psyllids (ACP). “Imidacloprid of course is typical of the neonicotinoids that we’ve been using as soil applications to protect young trees,” Stansly says. “We’ve seen and the growers have seen, too, that soil applications of systemic insecticides …
Single Breakthrough Discovery for HLB in Florida Unlikely
A single breakthrough discovery for managing citrus greening in Florida in the future is unlikely, says a new report by the National Academies of Sciences, Engineering, and Medicine. The committee that wrote the report called for a systems approach to prioritize research on the disease and strategically distribute resources for research to effectively manage the disease, which is the most …
USDA Researcher: Bactericides Increase Yields
Several trials indicate that after one year of application, bactericides increase citrus yields in HLB-infected trees compared to non-treated controls, a U.S. Department of Agriculture researcher reported Tuesday at the Florida Citrus Growers’ Institute. But the researcher, Robert Shatters, says the results are variable. “We’ve seen three studies now, done totally separately in different ways, and they all show about …
‘Flip’ Psyllid Control for Better HLB Management
Mike Irey of Southern Gardens Citrus explains why he thinks “flipping” the standard focus of psyllid control from young trees to mature trees can actually help young trees grow stronger in the face of HLB. Irey, director of research and business development, spoke at the recent International Citrus Business Conference in Daytona Beach. Irey explains that HLB is spread two …
Research Reveals a New Direction for Halting HLB
New clues to how the bacteria associated with citrus greening infects the only insect that carries it could lead to a way to block the microbes’ spread from tree to tree, according to a study in Infection and Immunity by Agricultural Research Service (ARS) and Boyce Thompson Institute (BTI) scientists. Citrus greening, also known as huanglongbing (HLB), is a serious disease dramatically …
Nutrition and HLB
University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) professor Kelly Morgan discusses the importance of nutrient leaf concentrations in HLB-infected citrus trees. “The leaf concentration (of nutrients) is reduced in all HLB trees,” he says. “We’ve known that for a long time, since HLB was found in Florida.” Morgan, who works at the Southwest Florida Research and Education …
Spoon-Feeding Nutrition and Protecting New Flush for HLB
Spoon-feeding nutrients through root systems and protecting new leaf flushes are among ways Jude Grosser believes growers can maintain tree health in the face of HLB. Grosser, a University of Florida Institute of Food and Agricultural Sciences professor, is best known as a citrus breeder. Grosser said he started working with nutrition because “like any grower, I don’t like to …
Georgia Citrus Association Taking Precautions Against HLB
Huanglongbing (HLB), or citrus greening disease, was a hot topic at the recent Georgia Citrus Association Conference held in Tifton. As the Georgia citrus industry continues to grow, it is taking precautions to prevent the spread of HLB. Lindy Savelle, president of the Georgia Citrus Association, said although HLB has not been detected yet in Georgia, the industry is preparing …
Hall of Famer Kahn: HLB Will Be Overcome
Sebring grower and grove manager Marvin Kahn, one of two inducted into the Florida Citrus Hall of Fame on March 9, says the industry will survive greening disease, or HLB. “I’m sure that we’ve got a real handicap now with this greening disease,” Kahn says. And no doubt we could have other diseases even following it. But with a real …
Browning to Take New Role in HLB Battle
Citrus Research and Development Foundation Chief Operations Officer Harold Browning will resign at the end of March to pursue HLB control strategies for Premier Citrus ApZ, a branch of Vero Beach-based Premier Citrus. At his new position, Browning says he will work “on further testing and commercialization of strategies to control HLB in the field.” Specifically, Browning will work with …
Nurseryman Discusses HLB, Grapefruit and Lemons
The impact of HLB on total citrus tree propagations, including the decline in grapefruit and growth in lemons, is addressed by nurseryman Nate Jameson. Jameson, owner of Brite Leaf Citrus Nursery, discusses some points he made at the annual Florida Citrus Show in January. “A few years ago we were propagating about 4.7 million trees a year,” Jameson says. “We’re …