By Kim D. Bowman, Matt Mattia, Ranjeet Shinde and Flavia Zambon Profitability of the historic kings of citrus in Florida, sweet orange juice and fresh market grapefruit, has been severely reduced by the impact of huanglongbing (HLB) disease. Previous studies have demonstrated that lemon cultivars are generally more tolerant to HLB than sweet orange and grapefruit. Lemon trees continue cropping …
Top Florida Varieties and Rootstocks
Valencia SPB 1-14-19 remained the most propagated Florida citrus variety for at least the fourth straight year in 2024–25, according to the Florida Department of Agriculture and Consumer Services (FDACS). The FDACS Division of Plant Industry’s Bureau of Citrus Budwood Registration recently released the Citrus Budwood Annual Report 2024–25. The report is a highly detailed 44-page document. US-942 returned as …
Study Shows Performance of New Rootstocks
A recent article provides estimates for the performance of Valencia orange grafted on new hybrid citrus rootstock cultivars developed by the U.S. Department of Agriculture-Agricultural Research Service (USDA-ARS). These estimates can help growers decide which rootstocks to plant in HLB-endemic regions. Authors of the article are Ariel Singerman of the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS), …
Agromillora Introduces New Citrus Rootstock
Agromillora, in collaboration with the Valencian Institute of Agricultural Research (IVIA), has introduced CIVAC-19, a new citrus rootstock. CIVAC-19 is the result of more than a decade of research between IVIA and Agromillora. It is a hybrid rootstock of Citrus reshni (Cleopatra mandarin) and Poncirus trifoliata (trifoliate orange). Its semi-dwarfing nature provides medium vigor, key for maintaining compact canopies and …
Influence of Rootstock and OTC Injection on Valencia Yield
By Kim D. Bowman, Ute Albrecht and Caroline Tardivo Profitability of citrus in Florida has been severely reduced by the impact of huanglongbing disease (HLB). Previous studies have demonstrated that rootstock selection and injection of established trees with oxytetracycline hydrochloride (OTC) can both significantly improve the health, cropping and fruit quality of trees affected by HLB. However, neither a superior …
Cantrell Contributes to Knowledge on HLB-Tolerant Rootstocks
Ryan Cantrell spent the summer of 2025 as a University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) intern contributing to knowledge about the devastating citrus disease HLB. The undergraduate student worked under the supervision of Assistant Professor Liliana Cano and Biological Scientist Edinson Diaz in the plant pathology laboratory at the Indian River Research and Education Center. Cantrell …
Rootstock Influence on Witches’ Broom Disease of Lime
An Iranian study in controlled greenhouse conditions has enhanced the understanding of the influence of rootstocks on limes infected with witches’ broom disease of lime (WBDL). The study has also led to the acknowledgement that WBDL management may require tolerance of both scions and rootstocks. Authors of an article about the study are Samaneh Raheb, Sina Noorizadeh and Morteza Golmohammadi, …
Rootstocks for Improved Tolerance to HLB
By Lamiaa Mahmoud and Manjul Dutt Utilizing tolerant rootstocks to combat HLB is a long-term management strategy that can help sustain productivity and enhance tree survival, especially when implemented alongside other HLB management approaches. Australian limes are tolerant to HLB, and their DNA can be incorporated into HLB-susceptible citrus using conventional breeding methods to enhance tolerance to HLB. Over the …
Top Florida Citrus Varieties and Rootstocks
Sour orange jumped six spots from the prior year to become the most-budded rootstock in Florida citrus nurseries in 2023–24. Rootstock US-942 had held the top spot for at least the last three years. Valencia SPB-1-14-19 easily maintained its spot as the most-budded variety clone. It has held the top spot for at least four straight years. The number of …
Survey Shows Popular Scions and Rootstocks
The Florida Citrus State of the Industry Survey seeks input from growers on key issues affecting their groves. The survey has been conducted for many years, has tracked the trajectory of HLB and reported on production practices. While not a scientific survey, it has reflected general trends over the years. Last month, we published results on trunk-injection therapy and the …
Tango Rootstock Trial Update
Members of the University of Georgia (UGA) Extension team recently wrote an update on a Tango rootstock trial in the Cold Hardy Citrus Connection. The authors were Jake Price, Mary Sutton, Doug Collins, Jacob Kalina, Josh Dawson, Holly Anderson, Michasia Dowdy, Sara Curry, Ben Reeves, Tucker Price and Justin Shealey. Edited excerpts follow: The Tango rootstock trial has been through …
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 …
Rootstocks Show Drought Tolerance in Brazil
The drop in Brazil’s 2024 citrus harvest is due, among other factors, to the long period of drought observed in the Citrus Belt, according to Fundecitrus. Mitigating problems related to periods of drought is the objective of several studies being conducted by Fundecitrus, Embrapa Cassava and Fruits, Coopercitrus Credicitrus Foundation and the Agronomic Institute (IAC). One of these studies takes …
More SuperSour Rootstocks Under Study
“Superior New Rootstocks Can Make Citrus Profitable Again” is the headline of a recent U.S. Department of Agriculture Agricultural Research Service (USDA ARS) article. Kim Bowman, research geneticist at the USDA Horticultural Research Laboratory in Ft. Pierce, Florida, write the article. A slightly edited version follows: The rootstock and root system are what make trees strong enough to survive and …
Rootstocks and OTC
The University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Citrus Research and Education Center hosted a May OJ Break educational seminar. Ute Albrecht, UF/IFAS associate professor of plant physiology, spoke during the event and gave an update on oxytetracycline (OTC) therapies being applied in citrus groves over the past two seasons. She gave a summary of research she …
CITRUS NURSERY SOURCE: A Day of Learning About New Rootstocks and Varieties
By Peter Chaires The U.S. Department of Agriculture-Agricultural Research Service (USDA-ARS) U.S. Horticultural Research Laboratory and Florida Citrus Research Foundation (FCRF) jointly held an open house, variety display and field tour at the W.H. Whitmore Foundation Farm between Leesburg and Groveland in early December. This annual event provides a great opportunity for industry members to see the latest innovations in …
New Results From Owari Rootstock Trial
By Jake Price Rubidoux is considered the standard rootstock for Georgia, but it was not obtainable from U.S. Department of Agriculture (USDA)-certified nurseries in Florida in 2014 and 2015 because it is not a rootstock used in Florida. It is a proven rootstock in Georgia known for cold hardiness but did not perform well in a multiyear trial. The chart shows …
Rootstocks and More Showcased at Field Day
In early December, the U.S. Department of Agriculture-Agricultural Research Service (USDA-ARS) hosted its annual A.H. Whitmore Foundation Farm field tour and variety display in Groveland, Florida. The event was well attended and showcased the USDA-ARS citrus scion and rootstock breeding program. Attendees loaded up for a hayride and guided tour through the grove. One stop showcased the cooperative work the …
Rootstocks Influence Cold-Hardiness of Georgia Tangos
Since the Christmas freeze of 2022, University of Georgia Lowndes County Extension Coordinator Jake Price has been conducting cold-hardiness ratings to see how Georgia citrus varieties were influenced by their rootstocks. He focused on Tango performance in a recent report and declared US-1516 “the clear winner” in providing cold-hardiness. Since January of 2023, Price has conducted ratings on how much …
Breeder Advice on Nutrition, Scions and Rootstocks
Citrus breeder Jude Grosser recently shared tips on tree nutrition and discussed some scion/rootstock combinations that should work well for trees producing juice oranges. NUTRITIONGrosser became very interested in citrus nutrition several years ago in an effort to keep his newly bred trees healthy in the face of HLB. The University of Florida Institute of Food and Agricultural Sciences professor …





























