Rootstock Offers High Hopes for HLB Tolerance, Maybe Resistance

Tacy CalliesRootstocks

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

Tacy CalliesResearch, Rootstocks

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 …

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 …

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 …

Root Hair Enhancement With Low Phosphorus Concentrations

Tacy CalliesNutrition

By Laura Waldo and Arnold Schumann It has been the accepted belief for many years that citrus varieties and rootstocks do not develop root hairs. However, research has shown that root hair growth can be stimulated when soil phosphorus (P) concentrations are extremely low. It is possible that in Florida, citrus roots could fail to produce root hairs due to …

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 …

soil

Soil Health Focus for HLB

Ernie Neffsoil

A citrus soil health field day recently attracted about 40 people to the Howey-in-the-Hills area to see growers’ success using cover crops and compost on Florida groves once stunted by HLB. Event organizer Juanita Popenoe, commercial fruit production Extension agent for Lake, Marion and Orange counties, comments on the groves’ success. Popenoe is with the University of Florida Institute of …

Studying Citrus Roots in the HLB Era

Tacy CalliesRoot health

By Lorenzo Rossi, Ute Albrecht and Evan Johnson Citrus root systems are confronted with many challenges that limit resource availability needed for tree productivity. Challenges are compounded by huanglongbing (HLB), which now affects nearly all citrus trees throughout Florida’s production areas. Contrary to the above-ground portion of the tree, study of the below-ground portion is considerably more difficult. This article …

Strategies for Stronger Roots

Tacy CalliesRoot health

Citrus growers discuss production practices to improve root health. By Tacy Callies What began as an experiment in Ben Krupski’s 10-acre grove in Howey-in-the-Hills, Florida, is now a common practice he uses as production manager for Lennon Grove Service. Four years ago, Krupski started testing the use of compost in his small leased block of Hamlin trees. In the first …

Components of a Healthy Citrus Soil

Tacy CalliesSoil Improvement

By Sarah Strauss and Ute Albrecht There is increasing discussion and interest in soil health from both growers and researchers. Soil health is generally synonymous with soil quality. It can impact not just sustainability, but also improve water-holding capacity, nutrient availability, yield and overall grove productivity. In citrus, soil health is particularly important because of the reduction of root mass …

HLB

Evaluating Roots of HLB-Infected Trees

Ernie NeffHLB Management

Growers attending a recent workshop in Sebring learned how to evaluate the root systems of HLB-infected trees. University of Florida Institute of Food and Agricultural Sciences researcher Evan Johnson was the instructor. Johnson said evaluation of root systems is important because “HLB is causing a lot of damage to the root system … It’s important to know how the pests …

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 …

root

Root Biologist Joins UF Fight Against Citrus Greening

Daniel CooperCitrus, Citrus Greening, Industry News Release, Research

By Robin Koestoyo, University of Florida Institute of Food and Agricultural Sciences An inventive fruit tree researcher has joined the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Indian River Research and Education Center. Lorenzo Rossi is the center’s first-ever root biology professor and will support the university’s statewide Institute of Food and Agricultural Sciences’ commitment to restore Florida’s $9 …

Root Weevil Management: Above and Below Ground

Tacy CalliesPests

By Jawwad A. Qureshi and Larry Duncan Root weevils are a major pest group for many kinds of plants, with at least nine species that colonize citrus. Species commonly infesting citrus include Diaprepes root weevil (Diaprepes abbreviates), blue-green citrus root weevils (Pachnaeus litus and Pachnaeus opalus), little leaf notcher (Artipus floridanus), Fuller rose beetle (Asynonychus godmani) and Sri Lanka weevil …

HLB

Super-Root Mutants for HLB

Ernie NeffCitrus Greening, HLB Management

A citrus nursery employee has found super-root mutants that might offer hope for developing trees that are less susceptible to HLB. The employee is Beth Lamb, a tissue culture expert at Phillip Rucks Citrus Nursery. University of Florida Institute of Food and Agricultural Sciences citrus breeder Jude Grosser tells about her discovery. “She discovered some mutants of some of the …

Rootstocks and HLB Tolerance — Another Perspective

Tacy CalliesHLB Management, Rootstocks

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, …

HLB

HLB and Root Longevity

Ernie NeffHLB Management, Rootstocks

University of Florida Institute of Food and Agricultural Sciences plant pathologist Evan Johnson tells how drastically HLB harms citrus tree roots and suggests some ways to prolong root longevity and improve tree health. “It (HLB) causes very substantial root loss, up to between 30 and 50 percent early in the disease process from before visual symptoms are present to early …

Controlled-Release Fertilizer Boosts Health of HLB Trees (Part 2)

Tacy CalliesCitrus, Nutrition

By Pete Spyke, Joby Sherrod and Jude Grosser Part 1 of this article, published in the April 2017 issue of Citrus Industry magazine, provided some background information on controlled-release fertilizer (CRF) along with a discussion of practical applications in citrus production. This article, part 2, includes summaries of observations from several case studies in which CRF has been applied for …

Controlled-Release Fertilizer Boosts Health of HLB Trees (Part 1)

Josh McGillNutrition

By Pete Spyke, Joby Sherrod and Jude Grosser Editor’s note: Look for part 2 of this article in the May 2017 issue of Citrus Industry magazine. Part 2 will present case studies using controlled-release fertilizer. Until now, most growers have considered controlled-release fertilizer (CRF) to be primarily for use on young trees, especially resets in existing groves. There is increasing …