Rootstock Effects on Valencia and Hamlin in Large-Scale Commercial Plantings

Tacy CalliesResearch, Rootstocks

By Ute Albrecht, Sudip Kunwar and Jude Grosser Prior to 1865, the only rootstocks used in Florida were sour orange and sweet orange. Use of grafted trees instead of seedling trees became necessary because of the devastating effects of phytophthora on sweet orange. Sour orange was widely used as a rootstock because of its resistance to phytophthora and other positive …

How to Use the New Florida Citrus Rootstock Selection Guide

Tacy CalliesRootstocks

By Rhuanito S. Ferrarezi, William S. Castle, Kim D. Bowman, Jude W. Grosser, Stephen H. Futch, Steve Rogers and Andres Gonzalez First published in 1989 as Rootstocks for Florida Citrus, the work of William Castle and his colleagues remains relevant 30 years later. The purpose of the fourth edition of the Florida Citrus Rootstock Selection Guide is to provide timely …

Lessons Learned From Rootstock Field Trials

Tacy CalliesResearch, Rootstocks

By Bill Castle “The notion that field trial data are of little value in the early years and trials must run for 15 years is outdated.”  [Lesson 7] “Our new website provides the grower community with user-friendly access to our collective decades of rootstock trial data…” [Lesson 9] Those are two of many lessons shared in a recent article authored …

soil

Nutrition and Rootstocks to Be Studied

Ernie NeffNutrition

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 …

Rootstock Trial Results on New Website

Tacy CalliesRootstocks

A new website with a wealth of information about citrus rootstocks is now available at https://citrusrootstocks.org/. Rootstock breeder Kim Bowman, with the U.S. Department of Agriculture (USDA) Agricultural Research Service in Fort Pierce, has posted results from 37 replicated multiyear rootstock field trials in Florida. The results can be easily accessed from the site by computer, tablet or smartphone.  According …

planting

Rootstock Selection Made Easier

Ernie NeffRootstocks

The recently released fourth edition of the Florida Citrus Rootstock Selection Guide is “way more user friendly” than past editions, one of its authors says. University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) researcher Rhuanito “Johnny” Ferrarezi says “a completely redesigned website” is what makes the guide so useful for growers. Ferrarezi works as an assistant professor at …

graft

Some Scions Incompatible With US-1283 Rootstock

Daniel CooperIndustry News Release, Rootstocks

By Kim D. Bowman and Ute Albrecht The US-1283 rootstock was released by the U.S. Department of Agriculture (USDA) in 2014, based on field performance with Hamlin 1-4-1 sweet orange in trials at two different locations in Florida severely affected by huanglongbing disease. One of these trials was in St. Lucie County and of 14 years duration, while the second …

new grove

Thoughts on the Scion and Rootstock Selection Process

Tacy CalliesRootstocks, Scions

By Bill Castle If timing is everything, then let me suggest that the timing is right to consider the following proposals about making scion and rootstock choices in the Florida citrus industry: What to plant? That is a huge question that could be initially addressed by a one-day program carefully planned as to objectives, format and participants. I was reminded …

CRAFT program

Citrus Rootstock Guide Updates Available Online

Daniel CooperIndustry News Release, Rootstocks

(UF/IFAS) — Florida’s citrus growers may now access the updated Florida Citrus Rootstock Selection Guide, which is more user- and mobile-friendly. Revisions include current University of Florida rootstock horticultural traits, three new rootstocks that tolerate citrus greening and an updated bibliography. “The fourth edition of the Florida Citrus Rootstock Selection Guide has a new look and information for a comprehensive description …

rootstock

Rootstock Work Discussed

Ernie NeffRootstocks

University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) plant physiologist Ute Albrecht discusses her research on citrus rootstocks. Albrecht points out that sour orange was the dominant rootstock in Florida several decades ago, until trees on the rootstock succumbed to citrus tristeza virus. “Now we have many other rootstocks that are beneficial for different reasons,” she says. Those …

Advice on Picking Rootstocks

Ernie NeffRootstocks

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 …

HLB

Rootstock Solutions for HLB

Ernie NeffHLB Management, Rootstocks

University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) citrus breeders are working on both short-term and long-term rootstock solutions for HLB, Fred Gmitter said earlier this year. Gmitter and fellow UF/IFAS citrus breeder Jude Grosser have already identified numerous rootstocks that seem to offer tolerance to the disease. Tolerance would help growers in the short term. Gmitter says …

Grower Picks Favorites at Rootstock Trial

Ernie NeffRootstocks

Gardinier Florida Citrus General Manager Lee Jones named two rootstocks that looked appealing at an April 25 Citrus Research and Development Foundation (CRDF) rootstock field day in Highlands County. “(US) 942 kind of stands out to me,” he said. “(US) 812 looks good,” he added. “What we’re learning as we’re going is we’ve got to spoon feed this (citrus trees) …

citrus rootstock

USDA Releases 3 New Citrus Rootstocks

Daniel CooperCitrus, 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 ContentGrower Results With ReMedium TI® Mirror Researcher ResultsJanuary 21, 2026Take Advantage of Rising …

Rootstock/Scion Combos: What Works and What Doesn’t

Tacy CalliesRootstocks, Scions

By Ernie Neff For Phil Rucks and Tom Powers at Phillip Rucks Citrus Nursery in Frostproof, Florida, selecting rootstock and scion combinations starts by acknowledging that some varieties just don’t do well with HLB. “We don’t recommend some varieties regardless of rootstock,” Rucks says. Powers says varieties that are especially difficult to grow with HLB are Hamlin, midsweet and pineapple …

mandarin

Rootstock Choice May Be Key in Tree Productivity

Tacy CalliesRootstocks

Florida citrus growers recognize the Sugar Belle® mandarin hybrid for its tolerance of citrus greening disease, and new findings from the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) suggest that rootstock selection may play a role in keeping Sugar Belle® trees productive even if they become infected with the bacterial malady. “We now have proof of concept …

Field Testing of New HLB-Tolerant Scions and Rootstocks

Tacy CalliesResearch, Rootstocks, Scions

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 …

Alternatives to Rootstock Propagation by Seed: Differences, Concerns and Expectations

Tacy CalliesResearch

By Ute Albrecht Commercial citrus rootstock propagation traditionally occurs via use of nucellar apomictic seed, which generates genetically identical seedlings that are used as liners for budding. With the high demand for superior rootstocks in the age of HLB, commercial nurseries are currently experiencing a shortage of seeds for some of the most popular rootstock varieties. In addition, for many …

rootstocks

Some Rootstocks Succumbed to Irma

Ernie Neffhurricane, Rootstocks

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 …