Use of CRISPR (clustered regularly interspaced short palindromic repeats) technology has already produced trees that are highly resistant to citrus canker. In a Citrus Expo virtual presentation, microbiology and cell scientist Nian Wang reported on work that is being done with CRISPR to develop tree resistance to HLB. Wang is a University of Florida Institute of Food and Agricultural Sciences …
Massive Research Project in Millennium Block
Researchers at the resurrected Millennium Block at Fort Pierce will assess the performance of new grapefruit cultivars and evaluate numerous rootstocks in the face of HLB. University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) researcher Rhuanito “Johnny” Ferrarezi discusses the history of the block and research planned there. The block is called Millennium because some researchers planted variety …
Nursery Diseases at Planting: What to Watch for
By Ozgur Batuman and Megan Dewdney Citrus nurseries work very hard and put forth considerable effort to reduce pest and disease problems. However, there continues to be problems with certain diseases, because the nursery environment for growing citrus trees is ideal for many pests and diseases. Basic principles of good nursery sanitation practices together with screening and removing suspected or …
Planning for Foliar Disease Management in 2020
By Megan Dewdney and Evan Johnson In 2019, the trend of fewer problems with foliar fungal diseases for Florida citrus continued, which was good news for the industry. Despite the El Niño conditions during the spring, little postbloom fruit drop (PFD) was observed because the temperatures were low (< 75 F) when it rained during bloom. The southern parts of …
IPCs for HLB Prevention in Young Trees
By Fernando Alferez, Susmita Gaire, Ute Albrecht, Ozgur Batuman, Jawwad Qureshi and Mongi Zekri Controlling the Asian citrus psyllid vector of huanglongbing (HLB) is critical, especially in young trees. Reducing HLB incidence is essential for tree survival and productivity under current endemic conditions. Individual protective covers (IPCs) are a novel strategy based on psyllid exclusion by means of a protective …
Grapefruit and Marathon Discussed
University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) plant breeder Fred Gmitter discusses efforts to create a replacement for grapefruit. He also talks about the recently released mandarin variety, Marathon. Gmitter points out that grapefruit is “one of the most sensitive of all the citrus varieties” to HLB dusease and has “taken the greatest hit” in terms of …
Production Guide: What’s New
The three editors of the new Florida Citrus Production Guide recently told growers at a meeting in Sebring what’s new in the guide this year. The University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) produced the guide. Megan Dewdney, a UF/IFAS plant pathologist, addresses new information provided about diseases. New items include the addition of a chemical for …
HLB Early Detection Methods Available Now; More Coming Soon
By Len Wilcox Early detection has become a vital line of defense in the California citrus grower’s war with huanglongbing (HLB) disease. Without careful monitoring, any tree in the grove can become a ticking time bomb that could lead to destruction of the entire orchard. The disease starts unnoticed. Many months can pass before a tree displays any visible evidence …
CRDF 2018 Funding Cycle Is in Full Swing
Column sponsored by the Citrus Research and Development Foundation (CRDF) On April 24, the CRDF board of directors approved research priorities for two separate research funding programs. One is for projects that will lead directly to the development of commercial products, tools or recommendations (Commercial Product Development Committee, CPDC-18). The other is for projects with broader, fundamental researchable questions (Research …
Nurseryman Discusses HLB, Grapefruit and Lemons
The impact of HLB on total citrus tree propagations, including the decline in grapefruit and growth in lemons, is addressed by nurseryman Nate Jameson. Jameson, owner of Brite Leaf Citrus Nursery, discusses some points he made at the annual Florida Citrus Show in January. “A few years ago we were propagating about 4.7 million trees a year,” Jameson says. “We’re …
Managing Disease with Copper and IPM
Integrated pest management (IPM) strategies and copper are both good control measures for common citrus foliar fungal diseases, as well as for citrus canker. So says University of Florida Institute of Food and Agricultural Sciences plant pathologist Ozgur Batuman. Batuman summarizes information he presented at a fall field day and seminar attended by about 60 people at the Southwest Florida …
Millennium Block Resurrected for HLB Research
An approximately 35-acre research plot that fell victim to citrus canker years ago will soon become a new research site helping growers pick trees that fare best with HLB. The plot at the Indian River Research and Education Center (IRREC) in Fort Pierce will keep its former name, the Millennium Block. University of Florida Institute of Food and Agricultural Sciences …
UF/IFAS Microbiologist Works Toward Greening Treatment
by Brad Buck, University of Florida Institute of Food and Agricultural Sciences In the same year the University of Florida’s (UF) Citrus Research and Education Center (CREC) celebrates its 100th anniversary, Nian Wang believes he may be close to finding the “off switch” for greening, the disease devastating Florida’s multi-billion-dollar-a-year citrus industry. Wang, an associate professor of microbiology and cell sciences …
Field Trials of Rootstocks and Scions: What Can They Tell Us?
By Harold Browning Column sponsored by the Citrus Research and Development Foundation Plant breeding programs have been a mainstay of citrus production worldwide. They have served as a basis for gradual improvement in fruit quality, adaptability to varying growing environments, and most importantly, to disease management. For that reason, new germplasm has been a front line of pursuit in the …
Preparing for and Recovering from a Hurricane
By Mongi Zekri, Bob Rouse and Jonathan Crane Hurricane preparation for citrus growers this year is the same drill as every year. Each year, growers look forward to the rainy season to help their young trees grow fast and their mature trees produce good crops. This year, growers will be praying for good distribution of rains following a year of …
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 …
From Planning to Planting: Establishing New Groves in the Presence of HLB
By Ute Albrecht Despite the constant threat of huanglongbing (HLB), most growers remain optimistic and are replanting citrus trees to maintain production levels necessary for sustaining the industry. The tax incentive bill under the Emergency Citrus Disease Response Act introduced in December 2015, if implemented, will help growers get back expenses associated with replanting of diseased trees immediately, instead of …
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 …
Hurricane Preparedness
By Bob Rouse and Mongi Zekri Little can be done to protect trees and fruit from hurricane velocity wind, but we can take steps to protect the people, equipment and supplies that will be needed for the recovery. Below is a checklist for citrus grove managers. Pre-Hurricane Preparation Checklist Personnel assignments: 1. Make a list of all tasks and make …
Pruning to Rehabilitate HLB-Affected Sweet Orange Trees
By Tripti Vashisth and Troy Gainey In the last 11 years, Florida orange production has declined more than 60 percent. This dramatic reduction in yield is attributable to multiple causes, including loss of citrus acreage in the state, citrus canker and other diseases, but huanglongbing (HLB) is now recognized as the primary reason for declining citrus yields. HLB-affected trees are …