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 …
Trunk Injection: Rootstock vs. Scion
By Ute Albrecht, Larissa Nunes and Gabriel Pugina The current label recommends trunk injection of oxytetracycline (OTC) into the rootstock, but this may not always be possible. Previous University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) studies have shown that both rootstock and scion injections are effective. However, researchers have not yet studied if different rootstocks influence …
California Lemon Rootstock Research Reported
Researcher Glenn Wright recently reported how various rootstocks for lemon trees producing fresh market fruit compared for yield and other qualities in three California locations with different climates. Wright is a University of Arizona associate professor and Extension specialist for tree crops. SANTA PAULASanta Paula’s warm summer Mediterranean-like climate had the following results: LINDCOVEResearch in Lindcove, a hot summer Mediterranean-like …
Grapefruit Rootstock/Scion Research Update
University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) researchers Mark Ritenour and Flavia Zambon recently provided an update on a large field trial. The project is called Evaluation of Potential HLB Tolerant Grapefruit Rootstock/Scion Combinations in the Indian River District of Florida. A summary of their update follows: The project started as a collaborative effort between the UF/IFAS …
USDA Citrus Breeding Program Focused on Rootstock and Variety Solutions
The U.S. Department of Agriculture’s (USDA) U.S. Horticultural Research Laboratory in Fort Pierce, Florida, has been home to a citrus rootstock and variety breeding program for many years. Kim Bowman, a research geneticist, has been with the program for more than 30 years. More recently, Matthew Mattia, a geneticist, joined the breeding team. They provide an update on the program …
Valencia on US-942 Rootstock Is Favored Florida Tree
For at least the last four years, the Valencia SPB-1-14-19 orange has been the most-produced citrus variety in Florida, and US-942 has been the favored rootstock. So, it makes sense that the Valencia SPB-1-14-19 on US-942 rootstock has been the most-produced tree combination for four years running. That information was provided at April’s Florida Citrus Growers’ Institute in Avon Park …
Rootstock Influences Cold-Hardiness in Sugar Belles
Sugar Belles on four different rootstocks in Georgia showed different levels of damage from the December 2022 freeze, reported Jake Price, Lowndes County Extension coordinator for University of Georgia Extension. The Sugar Belles at a Valdosta research plot planted in 2018 have put on the first flush of foliage after being mostly defoliated. The trees are snuggly located between windbreaks …
Nutrient Uptake Potential of Rootstocks
The objective of a new study published in HortScience was to evaluate and understand the nutrient uptake potential of citrus rootstocks. Conducted by University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) researchers, it is one of the first citrus studies to report nutrient uptake efficiency and the potential of rootstocks. The information presented in the study can be …