HLB pre-screening through analyzing plant metabolism holds potential to be a relatively inexpensive option for growers. Caroline Slupsky, professor in the Department of Nutrition and Food Science and the Department of Technology at the University of California, Davis, is looking at the metabolism of citrus trees and analyzing changes as indicators of stress and disease. Plants’ metabolic pathways change in …
Controlling HLB with Thermotherapy: What Have We Learned So Far?
By Reza Ehsani, Megan Dewdney and Evan Johnson In the last two years, many growers looked at thermotherapy as a way of keeping HLB-affected citrus trees in production until a more permanent solution could be developed. It has been shown that thermotherapy can kill HLB-causing bacteria under controlled environments. But the exact time and temperature is not known, and it …
Root Nutrition Key in HLB-Infected Trees
University of Florida researcher Jude Grosser focused on root nutrition during the Citrus Nutrition Day at the Citrus Research and Education Center on October 11. In this report, he says citrus roots impacted by HLB are missing the nutrients they need and discusses possible solutions, including what he calls “hybrid nutrition programs.” “We’ve gotten kind of too focused on what’s …
Indian River Citrus Grower on Canker, HLB and Bactericides
Canker and HLB have made things very difficult for Indian River citrus growers, but outgoing Indian River Citrus League President Scott Lambeth is optimistic about bactericides. “For the last three years with the contraction of the industry, it’s very difficult to keep an open mind and stay positive when you see family farms that are third and fourth generation still …
HLB-Spreading Psyllids: Incidence and Intensity
Citrus growers sometimes ask University of Florida entomologist Phil Stansly why they should continue to spray for HLB-spreading psyllids when trees are already infected with the disease. Stansly answered that question at Citrus Expo in August. “There are two issues with HLB,” Stansly says in this interview with Tacy Callies summarizing his Expo presentation. “One is incidence. In other words, …
Pruning to Rehabilitate HLB-Affected Sweet Orange Trees
By Tripti Vashisth and Troy Gainey In the last 11 years, Florida orange production has declined more than 60 percent. This dramatic reduction in yield is attributable to multiple causes, including loss of citrus acreage in the state, citrus canker and other diseases, but huanglongbing (HLB) is now recognized as the primary reason for declining citrus yields. HLB-affected trees are …
Update on Thermal Therapy for HLB
University of Florida researcher Reza Ehsani updated growers at Citrus Expo in August about research into the use of heat treatment of HLB-infected trees. Approximately 80,000 trees were heat treated in Florida in the past year, he says. Ehsani discusses some key issues regarding thermal therapy. “Finding the right time and temperature is critical to using this technique,” he says, …
Planting New Groves in the Face of HLB
Planting new groves in the face of HLB has become a daunting task for Florida growers. At the recent Citrus Expo, University of Florida researcher Ute Albrecht offered suggestions for those taking on the challenge. “Among the important things to consider when planting new groves are the site preparation, the planting of the trees, weed management, irrigation and nutrition, and …
Evaluation of HLB Treatments
By Stephanie Slinski Evaluating how well bactericides, nutritional programs or other treatments work against HLB can be difficult. Symptoms are not uniform between trees in a grove, and tree health fluctuates throughout the season, which may give the appearance of an effect. Rigorous field trials are the best way to test new treatments, but not every treatment program can be …
Trees Look Good but PFD and HLB Will Impact Yield
Several citrus growers attending a grower forum in Sebring last week said groves are looking very good even though fruit production is expected to be low this season. John Barben, a Highlands County grower and the new president of Florida Citrus Mutual, summarized the situation. “Trees are looking good,” Barben said. “We had a lot of rain the last couple …
HLB and ‘Tolerance’ as a Practical Matter in Choosing Rootstocks
By Bill Castle (Editor’s note: Click on the graphs throughout the article to enlarge them.) By classic biological definition, a particular citrus rootstock-scion combination when infected with Candidatus Liberibacter asiaticus (CLas) would be considered tolerant if infected trees had no more than slight reductions in performance, sometimes accompanied by a reduced level of the pathogen. That definition implies that the …
EPA Approves KPHITE® RX Systemic Bactericide for HLB Control
Florida-based Plant Food Systems announced that the Environmental Protection Agency (EPA) approved the use of KPHITE® RX Systemic Bactericide for the control of HLB or citrus greening. The approval was granted based on research conducted by a panel of researchers demonstrating that the use of KPHITE® RX and Renew® RX reduces the effects of greening on citrus crops. Further field …
Research on HLB-Tolerant Varieties Conducted in Gainesville
Research on HLB-tolerant trees and better citrus varieties is being conducted in Gainesville, outside the Florida citrus belt. University of Florida scientist Jose Chaparro discusses the work. “In Gainesville we have essentially the youngest citrus breeding program in Florida,” Chaparro says. “In the future, we hope to be able to provide both HLB and canker resistance in our selections.” Such …
HLB Playbook for Growers in the Works
Michael Rogers, director of the University of Florida’s Citrus Research and Education Center, discussed the planned HLB Playbook at the recent Citrus Expo. The playbook should be available in print and on the Internet by January. Rogers says the playbook will feature “all the information we know about managing citrus groves in the face of HLB and how growers can …
Panel on Bactericides for HLB Summarized
Harold Browning, chief operating officer of the Citrus Research and Development Foundation, summarizes a Citrus Expo panel in which four growers discussed their use of bactericides for HLB. The bactericides became available for use for HLB this spring. “They’re kind of working in the dark,” Browning says of the panelists and other growers trying bactericides. “They’re having to test and …
Snively Discusses Use of Bactericides for HLB
Jim Snively of Southern Gardens Citrus says his company is trying bactericides for HLB on one-tenth of its 10,000 citrus acres. The company is working with the Citrus Research and Development Foundation to analyze fruit drop, tree condition and more in blocks treated with bactericides. He believes it will take two to three years to determine if the bactericides are …
Southern Gardens Citrus to Host HLB Webinar
Rick Kress, senior vice president of research commercialization for Southern Gardens Citrus will present a webinar titled “Can We Live Without Citrus?” on August 25 from 11:00 a.m. to 12:00 p.m. EDT. Can you imagine what your store would look like if the orange juice section was suddenly empty or produce shelves were void of all oranges, grapefruit, lemons and …
EPA Approves Temporary Use of Bactericides for HLB
The federal Environmental Protection Agency (EPA) this week approved the temporary use of three bactericides on HLB-infected citrus trees. Florida citrus growers had already been using the products this year because Florida Commissioner of Agriculture Adam Putnam issued a crisis declaration allowing their use. Citrus Research and Development Foundation Chief Operations Officer Harold Browning announced the EPA decision at Citrus …
HLB Experiences and Thoughts Shared
Tom Stopyra, technical crop advisor for The Packers of Indian River, shares experiences with HLB and offers opinions on numerous other topics he addressed at a recent seminar in Immokalee. Regarding the record high populations of HLB-spreading psyllids throughout Florida’s citrus belt this year, Stopyra says: “We’ve never seen populations like we have this year, even though we’ve been spraying …
California Citrus Challenges: Water Tops HLB
Asian citrus psyllids are detected sporadically in the San Joaquin Valley — home to most California oranges and mandarins — and are endemic in Southern California lemon country. But as far as anyone knows, the pests that spread HLB in Florida and Texas have not spread the disease into California’s commercial citrus groves. California HLB detections have been limited to 17 …





























