Communicating about genetic engineering as a partial solution to greening disease (HLB) was the topic of a recent OJ break in Sebring. Florida Department of Citrus (FDOC) Executive Director Shannon Shepp participated in the meeting and discusses the FDOC’s role in telling consumers about greening. “We’re very clear on the fact that biotechnology research is happening … We know that …
Managing HLB Horticulturally
University of Florida researcher Tripti Vashisth at Citrus Expo in August discussed the horticultural steps that can best help growers with managing HLB. She summarizes her presentation in an interview with Citrus Industry magazine. “The most important thing with managing HLB-affected groves is you want to fertilize your groves with good nutrition,” she says. She also emphasizes the need for …
Genetic Engineering for HLB – the Growers’ Role
Citrus growers can play a vital role in promoting genetic engineering as a partial solution to HLB, University of Florida Horticultural Sciences Department Chairman Kevin Folta says. He summarizes a message he delivered to about 40 at a Highlands County OJ break in Sebring on November 17. “There are many great innovations at the University of Florida and other places” …
HLB-Spreading Psyllids: Dormant Sprays and the Edge Effect
University of Florida entomologist Phil Stansly discusses the use of dormant sprays for HLB-spreading psyllids. He also addresses the fact that psyllid populations are often higher on grove perimeters — the so-called “edge effect.” Stansly says the next coordinated grower spray for psyllids in the Gulf citrus-growing region will be a dormant spray. “The trees are dormant now and that’s …
From Planning to Planting: Establishing New Groves in the Presence of HLB
By Ute Albrecht Despite the constant threat of huanglongbing (HLB), most growers remain optimistic and are replanting citrus trees to maintain production levels necessary for sustaining the industry. The tax incentive bill under the Emergency Citrus Disease Response Act introduced in December 2015, if implemented, will help growers get back expenses associated with replanting of diseased trees immediately, instead of …
Citrus Replanting Incentives in Face of HLB
More than 50 attended a November 1 workshop in Lakeland to learn about incentives to induce citrus tree replanting. Replanting is needed to replace trees lost to HLB and other problems. Kayla Nickerson of the Florida Department of Agriculture and Consumer Services (FDACS) talks about a relatively new incentive – her agency’s Citrus Grove Renovation/Re-establishment Support Program. Nickerson says, “We’re …
Managing the Health and Productivity of HLB-Affected Groves
By Tripti Vashisth In 2005, huanglongbing (HLB or citrus greening disease) was first discovered in Florida. Florida orange production changed from 242 million boxes in the pre-hurricane, pre-HLB, 2003–2004 season to 81.5 million boxes in 2015–2016. This dramatic reduction in yield is attributable to multiple causes, including a reduction in citrus acreage, citrus canker and other citrus diseases. HLB is …
Some Growers ‘Being Squeezed More than Others’ by HLB
Citrus Extension agent Steve Futch answers questions following a grower forum in Arcadia on October 27. Growers discussed production, bactericides for HLB and much more. The forum opened with one grower saying he doesn’t know how much longer he can keep going. Another reported per-acre orange production of 450 to 500 boxes in some blocks – a superb level in …
Analyzing Volatile Organic Compounds to Detect HLB
Another early detection and screening process for HLB has been developed at the University of California, Davis. Cristina Davis, professor of mechanical and aerospace engineering, is using volatile organic compounds (VOCs) as indicators of disease in trees. VOCs are odors that are emitted by all living things. These odors can be very meaningful, because they are distinctively different between a …
Monitoring Plant Metabolism to Detect HLB
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 …