By Ute Albrecht, Bo Meyering, José Chaparro and Kim D. Bowman Grafting is an ancient horticultural technique. There is evidence of citrus grafting in the Roman era dating back to the fifth century. In western Europe, grafting was regularly practiced in the 16th and 17th centuries when citrus was grown as an exotic ornamental in containers in orangeries. In Florida, …
Australia to Test UF’s HLB-Tolerant Rootstocks
HLB-tolerant rootstock seeds from the University of Florida (UF) have arrived in Dareton and Bundaberg to be evaluated under Australian conditions. Citrus Australia CEO Nathan Hancock said it’s important that the rootstocks have arrived in Australia well before the Asian citrus psyllid (ACP) and the HLB it spreads. “We need to know if these rootstocks from Florida are going to …
Heavy Fruit Loads in Rootstock Trials
Heavy fruit loads have created a problem for Owari satsuma rootstock trials in Valdosta, University of Georgia Extension agent and Lowndes County Extension Coordinator Jake Price reported recently. “It has been a struggle the last month or so to keep fruit off the ground because of the heavy fruit load,” says Price. “Fruit touching the ground will rot and fall …
Research on Rootstocks: More Than HLB
Plant breeders Fred Gmitter and Jude Grosser report on their efforts to develop rootstocks that perform well in Florida from several perspectives. In addition to seeking tolerance to HLB, they are working on rootstocks that might control tree size, deal with other diseases and pests and perform in a range of soils. Gmitter and Grosser are University of Florida Institute …
Rootstocks US-812, US-942 Hold Promise
The rootstocks US-812 and US-942 seemed to offer promise in early economic performance evaluations that economist Ariel Singerman discussed at the 2021 Citrus Expo. Singerman is a University of Florida Institute of Food and Agricultural Sciences Extension economist at the Citrus Research and Education Center in Lake Alfred. Singerman analyzed yield and economic performance of rootstocks in commercial settings during …
Millennium Block Field Day Draws Growers
More than 50 citrus growers and researchers attended a field day Oct. 14 in Fort Pierce to view 154 new citrus scion-rootstock combinations. Some of the combinations will result in trees that tolerate HLB. The Millennium Block Drive-Thru Field Day occurred at the University of Florida (UF) Institute of Food and Agricultural Sciences Indian River Research and Education Center (IRREC). …
How to Work With UF/IFAS for a Rootstock Trial
By Bill Castle The University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Citrus Research and Education Center (CREC) plant improvement team has long been engaged in field research to evaluate new scions and rootstocks. That effort continues and has involved trials on public and private property. While public sites are valuable, they are limited in number. Thus, most …
Indian River Millennium Block Shows Rootstock Effects
By Rhuanito S. Ferrarezi, J. Martin Zapien-Macias, Mac Hossain, Tom James, Ronald D. Cave, Peter Spyke, William S. Castle, Jude W. Grosser, Fred Gmitter and Ed Stover In the last decade, huanglongbing (HLB) has reduced production of Florida grapefruit by 75%, mandarin by 78% and sweet orange by 52%. This decrease is significant for the Indian River District, which produces …
Valencia Performance and Rootstock Propagation Methods
By Ute Albrecht, Sameer Pokhrel and Kim D. Bowman According to the 2019–2020 Citrus Budwood Annual Report, there were 772,391 (20%) rootstock propagations from tissue culture and 224,346 (6%) from cuttings out of the 3.9 million total propagations that season. The report is from the Florida Department of Agriculture and Consumer Services. This unprecedented high number of vegetative (not from …
Sneak Peek: July 2021 Citrus Industry
Growers looking for advice on the subjects of rootstocks and varieties will find several pertinent articles in the July issue of Citrus Industry magazine. According to University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) citrus breeder Jude Grosser, Orie and Louise Lee (OLL) oranges are giving Valencias a run for their money. He discusses the beneficial characteristics of …
The Secret Ingredient of Developing New Citrus Rootstocks
By Bill Castle Creation, evaluation, release and commercial acceptance are dynamic, interactive activities that together constitute new rootstock development. Underpinning each of them is a commonly overlooked and rarely mentioned activity, professional judgment. Yet, it is something everyone has and recognizes as getting better with time and experience. It is a skill developed and refined over time from knowledge of …
Florida Growers Wanted for Rootstock Trials
The Citrus Research and Development Foundation (CRDF) is establishing a new project to evaluate the most promising citrus rootstocks in grower field trials. The rootstock trials are projected to be planted in the spring or summer of 2022. The goal will be to identify plant material with the traits needed for growers to realize the highest possible pound solids per …
Georgia Owari Rootstock Trial Update
Ongoing citrus rootstock trials being conducted by the University of Georgia (UGA) hold promise for Georgia’s growing citrus industry. Jake Price, UGA Extension agent and Lowndes County Extension coordinator, has produced six local citrus rootstock/variety trials with varying objectives. The oldest trial, planted in 2014, is growing Owari satsuma trees on standard and new trifoliate hybrid rootstocks. Each year, as …
Georgia Trials Offer Rootstock Choices
Ongoing citrus rootstock trials being conducted by University of Georgia (UGA) Cooperative Extension in Lowndes County hold promise for increased yields, improved fruit quality and greater disease resistance. Jake Price, UGA Extension agent and Lowndes County Extension coordinator, has six local citrus rootstock/variety trials with varying objectives. The trees are custom-produced by U.S. Department of Agriculture (USDA)-certified citrus nurseries in …
Choosing a Lemon Rootstock
By Kim D. Bowman Lemons are a relatively small part of the Florida citrus crop. But with more than 317,000 lemon trees propagated in Florida nurseries over the past two years, lemons are clearly gaining increasing interest from growers trying to find a crop that is easier to grow and with a quick return on investment. As is the case …
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 …
Long-Term Rootstock Evaluation Is Best
A variety of different findings in recent rootstock trials led to a conclusion that long-term evaluation of rootstocks is necessary to assess economic benefits to growers. That conclusion was part of a take-home message in Ute Albrecht’s virtual Citrus Expo presentation. Albrecht is a researcher with the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS). Her report was …
Rootstock and Scion Affect Orange Juice Flavor
By Yu Wang, Fred Gmitter and Jude Grosser A major concern for the citrus industry is a significant decline in production due to huanglongbing (HLB). In addition to the production shortfalls are losses due to fruit rejection by packinghouses and juice processing plants as a result of inadequate size and low sugar content. Bitterness and metallic off flavors in the …
Rootstock Offers High Hopes for HLB Tolerance, Maybe Resistance
The new Sugar Belle hybrid rootstock LB8-9xS13#16 has quite a history, according to University of Florida Institute of Food and Agricultural Sciences citrus breeder Jude Grosser. “This is one of several projects I did with Orie Lee toward the end of his Florida Citrus Hall of Fame career/life,” recalls Grosser. “We did a lot of brainstorming together, and he was …
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 …