By Amit Levy and Ozgur Batuman Citrus tristeza virus (CTV) is an important citrus pathogen that, in the past, had a dramatic effect on the citrus industry and caused the loss of almost 100 million trees worldwide. These trees were propagated on sour orange rootstock. The disease created a need for tristeza-tolerant rootstocks to sustain the citrus industry, because only …
Israel’s Dynamic Citrus Industry
By Stephen H. Futch and Ariel Singerman As home to three of the world’s major religions, Israel is one of the most diverse countries in the world. Besides its cultural diversity and historical importance, Israel is also a major citrus producer and exporter. Israel’s citrus industry began in 1882. As new immigrants moved to the country, they established many very …
HLB: Horticultural Practices
Scientists from numerous countries attending the International Citrus Research Conference on HLB in March reported on studies of horticultural practices that might help growers cope with the disease. Tripti Vashisth, a horticulturist with the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS), summarized their observations at the recent Florida Citrus Growers’ Institute. She shares those observations in the …
Rootstock Solutions for HLB
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
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) …
Soil and Water pH Play a Key Part in Nutrition
By Tripti Vashisth, Davie Kadyampakeni and Lushan Ghimire In the past few years, horticultural citrus grove management practices have changed significantly in Florida. It is a common observation across the state that huanglongbing (HLB)-affected trees respond well to complete and balanced nutrition programs. Therefore, citrus growers are currently focusing on intensive management of irrigation and nutrition. HLB-affected trees suffer a …
Indian River Citrus Trials Discussed
Researcher Rhuanito “Johnny” Ferrarezi recently discussed experiments on citrus varieties and citrus under protective screen (CUPS) in the Indian River area. Ferrarezi is a University of Florida Institute of Food and Agricultural Sciences assistant professor of citrus horticulture at the Indian River Research and Education Center (IRREC). One large trial Ferrarezi discussed will be of grapefruit, navel and mandarins on …
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 …
CRDF President on Field Trials and Communication
Citrus Research and Development Foundation (CRDF) President Larry Black discusses the organization’s potential role in large-scale field trials to demonstrate how citrus can be grown in the face of HLB. He also talks about a communication study showing how growers like to receive information about CRDF. The Citrus Research and Field Trial (CRAFT) program would be funded for approximately $8 …
Sting Nematodes: A Growing Problem for Young Trees
By Larry Duncan Successive hard freezes in Florida in the late 1980s resulted in widespread replanting of citrus groves. Within a few years, many groves on the Central Ridge had discrete patches of poorly growing, chlorotic young trees amid patches of vigorously growing trees. Stubby root symptoms on the declining trees suggested damage by sting nematodes (Belonolaimus longicaudatus). This nematode …
Drone Images Can Accurately Find, Count Citrus Trees
By using drone technology, Florida citrus growers can find out how many trees live in their groves and, eventually, they may detect the health status of the trees, a new University of Florida study shows. Imaging from unmanned aerial vehicles (UAVs) can accurately detect and count citrus trees and spaces where trees have had to be removed in groves, said …
Phytophthora: An Old Problem with New Challenges
By Evan Johnson Diseases caused by phytophthora continually threaten Florida citrus production. Brown rot can directly reduce yields of early maturing varieties including Hamlin and grapefruit, can delay harvest of fresh market fruit until infected fruit have dropped, or risk packinghouse rejection of the load because it can spread post-harvest. Foot and crown rot can kill trees but are uncommon …
New Extension Agent for Indian River Citrus Growers
A horticultural research scientist with experience in the development of disease-free citrus rootstock and disease-tolerant citrus varieties in Iran’s northern agricultural region will now serve the Indian River District’s growers. Amir Rezazadeh recently began his new position as multicounty fruit and field crops agent for the University of Florida’s Institute of Food and Agricultural Sciences (UF/IFAS) Extension in Saint Lucie …
Indian River’s Grapefruit Plight
Florida grapefruit trees have taken a much harder hit from HLB, also known as greening disease, in recent years than orange trees have. Grapefruit production has plummeted drastically, and growers are desperately seeking ways to keep trees alive and productive. The fruit’s troubles have hit especially hard in the Indian River area, known worldwide for its grapefruit. Indian River Citrus …
Recent Pest Concerns in Florida Citrus
By Lauren Diepenbrock While Asian citrus psyllids (ACP) are an ongoing concern in Florida citrus due to their role in spreading the bacterium associated with citrus greening, they are not the only pest of concern to growers. Citrus leafminer (CLM) and root weevils are two pests that have been raising concerns and adding to the challenge of managing productive citrus …
Italian Citrus Breeding
Citrus tristeza virus (CTV) began spreading in Sicily in the early 2000s because the Italian citrus industry’s standard rootstock was CTV-susceptible sour orange, reported Marco Caruso at a recent symposium of international citrus breeders. Consequently, approximately 74,000 acres will be replanted with CTV-tolerant rootstocks over the next few years, he said. Caruso, a citrus breeding expert with Italy’s Research Centre …
New UF/IFAS Citrus Trial Data Available Soon
New research data are coming from trials of citrus rootstocks, scions and combinations of the two that University of Florida scientists hope will broaden the options of greening-tolerant citrus varieties available to commercial growers. Michael Rogers, director of the Citrus Research and Education Center (CREC), part of the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS), said scientists …
Research Update: Citrus Under Protective Screen
By Arnold Schumann, Timothy Ebert, Laura Waldo, Danny Holmes, Napoleon Mariner, Gary Test, Chris Oswalt, Rhuanito Ferrarezi and Ricardo Lesmes Two studies with citrus under protective screen (CUPS) were established at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Citrus Research and Education Center (CREC) and Indian River Research and Education Center (IRREC) in 2013–14. The goal …
Increasing Yield Through High-Density Plantings
By Rhuanito Ferrarezi, Alan Wright and Arnold Schumann High-density plantings have been tested worldwide in advanced citrus production systems (ACPS) to increase efficiency of water, fertilizer and light, and to maximize yield per area. After the onset of huanglongbing (HLB) in Florida, canopy growth reduced drastically due to negative impacts on plant health, creating the need for new plant spacing …
USDA Grant Could Help Florida’s Grapefruit Industry
Florida’s grapefruit industry, devastated by citrus greening, may find hope in four ½-acre white-mesh screenhouses in a research field in Fort Pierce. The project will be funded by a $3.5 million grant from the U.S. Department of Agriculture (USDA) awarded to the University of Florida. Studies for the grant will take place inside and outside these structures, where 512 young …