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 Health Focus for HLB
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 …
New Grapefruit Rootstock, Scion Experiment
The world’s peerless grapefruit grows in the Indian River Citrus District. Balanced with sugar and tart, and a thin rind for easy peeling, the fruit is sold mostly for export to European and Asian markets, where it is a high-price delicacy. But the once-thriving industry is in decline, and a plant pathogen is present in all of the state’s grapefruit …
Studying Citrus Roots in the HLB Era
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
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
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 …
Evaluating Roots of HLB-Infected Trees
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 …
Rootstock Choice May Be Key in Tree Productivity
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 Biologist Joins UF Fight Against Citrus Greening
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
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 …
Super-Root Mutants for HLB
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
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 and Root Longevity
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)
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)
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 …
Managing the Health and Productivity of HLB-Affected Groves
By Tripti Vashisth In 2005, huanglongbing (HLB or citrus greening disease) was first discovered in Florida. Florida orange production changed from 242 million boxes in the pre-hurricane, pre-HLB, 2003–2004 season to 81.5 million boxes in 2015–2016. This dramatic reduction in yield is attributable to multiple causes, including a reduction in citrus acreage, citrus canker and other citrus diseases. HLB is …
Root Nutrition Key in HLB-Infected Trees
University of Florida researcher Jude Grosser focused on root nutrition during the Citrus Nutrition Day at the Citrus Research and Education Center on October 11. In this report, he says citrus roots impacted by HLB are missing the nutrients they need and discusses possible solutions, including what he calls “hybrid nutrition programs.” “We’ve gotten kind of too focused on what’s …
Nutritional Needs of HLB-Affected Trees
By Davie Kadyampakeni, Alisheikh Atta and Edilaine Traspadini Citrus trees require optimal nutrition to be able to maintain high fruit yields, canopy size and good root health. Adequate nutrition supports not only yield and growth, but also tree resilience to disease and environmental stress, which is particularly important in HLB-affected groves. A balanced mix of macronutrients and micronutrients is needed …
Video Shows Citrus Planting Method Has Many Benefits
Texas A&M University citrus scientists who developed a successful planting method to combat diaprepes root weevil found that the method also offers numerous other benefits. In 2013, researchers Mamoudou Setamou and Olufemi Alabi were looking for an effective non-chemical method to physically block the circular foliage-to-underground lifecycle of diaprepes. The pest was attacking citrus roots and killing trees. Their solution …
Sustaining Citrus Production in the HLB Era
The virtues of daily irrigation and increased micronutrient applications were among key points researcher Davie Kadyampakeni made in an Aug. 13 discussion of citrus production in the HLB era. Kadyampakeni is a University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) associate professor of soil, water and ecosystem sciences at the Citrus Research and Education Center in Lake Alfred. …





























