The Citrus Research and Development Foundation (CRDF) directors recently ratified the rootstock selections for the planned rootstock field trials and discussed the organization’s involvement in future research, CRDF Chief Operating Officer Rick Dantzler reported. The board ratified 10 rootstock selections for the new field trials, overseen by CRDF’s Select Committee on Plant Improvement. According to Dantzler, the field trials will evaluate …
Citrus Nematode and Resistant Rootstocks
University of Florida Institute of Food and Agricultural Sciences professor Larry Duncan discussed the citrus nematode (Tylenchulus semipenetrans) during a recent international webinar on plant parasitic nematodes hosted by ADAMA. T. semipenetrans has a worldwide geographical distribution, making it the most common plant parasitic nematode of citrus. According to Duncan, this pest is regulated by seasonal carbon flux in fibrous …
Varieties and Rootstocks Reviewed
In his virtual Citrus Expo presentation, Jude Grosser reviewed varieties and rootstocks showing promise for productivity in the face of HLB. Grosser is a University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) plant breeder. His presentation was based on work done by him and fellow UF/IFAS researchers Bill Castle and Fred Gmitter. Grosser said UF/IFAS released OLL-20 “based …
New Rootstocks in the Citrus Breeding Pipeline
By Jude Grosser, Fred Gmitter and Kim Bowman Two citrus breeding programs have identified several rootstocks that can currently be planted with confidence when combined with appropriate scions, including mid- and late-season oranges, and grown with emerging enhanced nutrition programs. These citrus breeding programs are at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Citrus Research and Education …
Nutrition and Rootstocks to Be Studied
Seventeen researchers have responded to the Citrus Research and Development Foundation’s (CRDF) request for very specific citrus nutrition research, the organization’s board of directors learned May 19. CRDF Chief Operating Officer Rick Dantzler said several advisory groups will review the proposals prior to the CRDF board choosing and funding selected proposals no later than September. The research requested by CRDF …
Advice on Picking Rootstocks
Growers who attended a recent Citrus Research and Development Foundation (CRDF) rootstock field day in Highlands County should look at similar CRDF trials when deciding what rootstocks to plant. That’s the opinion of Jim Graham, a CRDF project consultant who spoke at the event last month. The same six rootstocks with Valencia scions that are in field trials in Highlands …
USDA Releases 3 New Citrus Rootstocks
The U.S. Department of Agriculture has released three new citrus rootstocks that are available for unrestricted public use. The rootstocks are US SuperSour 1, US SuperSour 2 and US SuperSour 3. A new publication provides summary information about the new releases. Get the new publication here: Sponsored ContentA Simpler, Safer and More Effective Way to Fight HLBOctober 25, 20245 Facts …
Field Testing of New HLB-Tolerant Scions and Rootstocks
By Rhuanito S. Ferrarezi, Jude W. Grosser, Fred G. Gmitter, Ed Stover and Kim Bowman Citrus is Florida’s most important agricultural commodity. The state produces citrus for different markets: round oranges for juice; navels, mandarins, grapefruit and lemons for the fresh-fruit industry; and lemons for extracting peel oil for processing. Huanglongbing (HLB) disease affects all citrus varieties. Since the discovery …
Some Rootstocks Succumbed to Irma
Researchers inspecting their groves at the Southwest Florida Research and Education Center after Hurricane Irma found that trees on certain rootstocks were very likely to be uprooted. Fernando Alferez, a horticulturist at the Immokalee center, discusses the uprooted trees and hopes he has for fresh citrus growing. “This is anecdotal evidence from our experience here,” Alferez says. “What we saw …
Rootstocks and HLB Tolerance — Another Perspective
By Ute Albrecht Tolerance to a disease is generally defined as the ability to be productive in the presence of disease-causing organisms. This is contrary to resistance, which is defined as the ability to completely evade a pathogen due to specific resistance mechanisms. The question as to what defines an HLB-“tolerant” rootstock was posed in an article by Bill Castle, …
Field Trials of Rootstocks and Scions: What Can They Tell Us?
By Harold Browning Column sponsored by the Citrus Research and Development Foundation Plant breeding programs have been a mainstay of citrus production worldwide. They have served as a basis for gradual improvement in fruit quality, adaptability to varying growing environments, and most importantly, to disease management. For that reason, new germplasm has been a front line of pursuit in the …
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 …
Florida Growers Reminded to Complete State of Industry Survey
The 2024 Florida Citrus State of the Industry Survey will provide a current view of the status of the state’s citrus industry. Among the topics covered in this year’s survey are hurricane impacts and the use of trunk-injection therapies to improve the health of HLB-infected trees. If you are a grower or a consultant/caretaker (who can answer generally on behalf …
CITRUS NURSERY SOURCE: Georgia’s Citrus Team Is Shaping Up Nicely
By Peter Chaires Many have been following the development of the Georgia citrus industry with great interest and curiosity. Though satsuma remains the dominant fresh citrus crop, other varieties are in varying stages of trial and adoption. The University of Georgia (UGA) has been supporting citrus growers in this process for more than a decade. Wayne Hanna, though his appointment …
Field Day Featured Favorable Fresh Fruit Rootstock and Scion Combinations
The University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Indian River Research and Education Center recently hosted a field day showcasing its Millennium Block citrus grove. The field day went on despite the grove being impacted by a tornado associated with Hurricane Milton in October. The Millennium Block is one of the largest experimental trials examining fresh fruit …
Disease Concerns for Georgia Growers
Not all citrus disease concerns center around huanglongbing (HLB). While HLB disease garners much of the headlines because of its devastation to Florida’s citrus crop, growers in the cold-hardy citrus region should be mindful of other diseases that can devastate a crop if left untreated. Jonathan Oliver, University of Georgia (UGA) assistant professor and small fruits pathologist, highlighted some of …
Hurricane Damages Georgia Citrus Research Plot
Jake Price with University of Georgia (UGA) Cooperative Extension recently described Hurricane Helene damage to the UGA citrus research plot. His observations, slightly edited, are as follows: When I had a chance to look at our citrus research plot, I expected the worst. But to my surprise, all of the trees were still standing. There was limb breakage due to …
The Good, the Bad and the Ugly: Optimizing OTC Injections
By Ute Albrecht, Caroline Tardivo, Larissa Nunes, Gabriel Pugina, Gerardo Moreno and Jasmine de Freitas As growers are well into the second year of oxytetracycline (OTC) injections since approval for commercial use, more and more data are accumulating. The good news is that in all University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) trials, trees have been responding …
Psyllid Control Discussed at South African Citrus Symposium
Researchers Marcelo Miranda and Haroldo Volpe with Brazil’s Fundecitrus discussed control of the HLB-spreading psyllid during a recent visit to a South African research symposium and accompanying events. During the Citrus Research Symposium in Drakensberg, Miranda discussed studies developed at Fundecitrus on the management of the HLB-spreading psyllid (Diaphorina citri). In South Africa, HLB is caused by a bacteria different …
Factors to Consider When Planting a New Grove
Growers have numerous things to think about when planting a new grove. University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) citrus genetic improvement specialist John Chater discussed this topic during a recent Citrus & Specialty Crop Expo presentation. Following are highlights from his talk on establishing new varieties in a new citrus grove. PESTS AND DISEASES Soilborne pests …