Non-Certified Donaldson Trees: Limited Availability for Growers

Josh McGillFlorida Department of Citrus, HLB Management

The Florida Department of Citrus’ Program for Expedited Propagation (PEP) of HLB-tolerant and resistant trees was conceived during the 2022 Florida legislative session following the discovery of the Donaldson tree among the collection at Whitmore Farms. The goal is to provide the resources needed to ramp up availability of Donaldson trees and others like it, so that growers interested in …

Two New Tools in the Fight Against HLB Seek EPA Registration

Josh McGillHLB Management

The recent Florida Citrus Industry Annual Conference featured educational presentations on navigating production in an environment where HLB is endemic in groves. Two of those presentations focused on new technology being developed for use in citrus. Two companies, Elemental Enzymes and TJ BioTech, have been collaborating with the Citrus Research and Development Foundation (CRDF) to research their respective products’ potential …

greening

Microregion Maps in Brazil Help With HLB

Josh McGillBrazil, HLB Management, Research

Microregion maps developed by Fundecitrus should help Brazilian citrus growers make the necessary decisions to combat HLB disease, also known as greening. Fundecitrus explained that the incidence of HLB differs in the various regions of Brazil’s extensive citrus belt. To allow citrus growers to better understand the places where the disease is located, a study by Fundecitrus divided the belt …

Progress in Developing Improved Citrus Rootstocks to Mitigate HLB

Josh McGillHLB Management, Research, Rootstocks

By Jude Grosser, Manjul Dutt and Fred Gmitter Exploiting citrus genetic diversity is the key to defeating HLB. Plant species have survived for millennia with evolving, hostile pathogens. This is possible through natural selection within genetically diverse populations. Tolerant or resistant individuals survive and intermate, get through the bottleneck, and the species evolves. Current citriculture is based on extremely limited …

Evaluation of Citrus × Microcitrus Hybrid Scions

Josh McGillResearch, Varieties

By Ute Albrecht, Anas Fadli and Chandrika Ramadugu Most commercially available citrus scion cultivars are highly attractive to the Asian citrus psyllid and susceptible to HLB. There are some citrus species, however, that are HLB tolerant or resistant. This may be because they are less attractive to the psyllids and/or because they restrict pathogen proliferation and therefore HLB disease development. …

California HLB Quarantine Areas Expanded

Josh McGillCalifornia Corner, HLB Management, Regulation

Federal and state officials in late June expanded the areas quarantined for huanglongbing (HLB, also known as citrus greening), caused by Candidatus Liberibacter asiaticus, in California. The U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) took the action in cooperation with the California Department of Food and Agriculture (CDFA). APHIS added portions of Los Angeles, Orange, Riverside …

Alternative Management Tools for ACP Under Development

Josh McGillEducation, HLB Management, Psyllids

By Lourdes C. Pérez Cordero Management of the Asian citrus psyllid (ACP) in the HLB era is incredibly important. This well-known insect can vector and facilitate the spread of the bacterium associated with HLB disease. Therefore, effective reduction of ACP populations can be beneficial for the citrus industry. But how exactly do we manage this pest? Unfortunately, there is not …

psyllids

Second CLas-Positive Psyllid Sample Found in California Grove

Josh McGillCalifornia Corner, Pests, Psyllids

An Asian citrus psyllid (ACP) sample confirmed positive for Candidatus Liberibacter asiaticus (CLas) — the bacteria that causes huanglongbing (HLB) — was collected from a commercial citrus grove in the Pauma Valley area of California’s San Diego County. This confirmation marks the first CLas-positive ACP found in a commercial grove in San Diego County and only the second grove detection …

Combining IPCs and Brassinosteroids to Protect Young Citrus Trees

Josh McGillIPCs, Research

Research studies show that about 60% of Florida citrus trees are infected by HLB disease within six months of planting. By one year, 100% of citrus trees are infected. For that reason, the use of individual protective covers (IPCs) has become very popular to protect young citrus trees from the Asian citrus psyllid (ACP). The covers have proven to be …

Reduce HLB Pressure and Enhance Growth With Kaolin

Josh McGillHLB Management, Tip of the Week

By Christopher Vincent Kaolin particle film is a non-toxic tool to reduce psyllids and increase tree growth. Particle films are nothing more than a suspension of solid particles that make a “film” on the leaves after they dry. They work mostly by reflecting light. Kaolin is the most common type of particle film because the clay is mined directly and …

California Panel Issues HLB Update

Josh McGillCalifornia Corner, HLB Management, Pests

California’s commercial citrus groves remain free of HLB disease 14 years after Asian citrus psyllids (ACP) were first detected there. The state’s Citrus Pest and Disease Prevention Program (CPDPP) described that as “no small feat” in its recently released 2020-21 annual report. “The past fiscal year presented its fair share of headwinds for citrus-growing operations,” the report stated. “From pandemic-induced …

Sneak Peek: July 2022 Citrus Industry

Josh McGillRootstocks, Sneak Peek, Varieties

HLB continued to contribute to reduced production and lower quality fruit for Florida growers this season. University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) researchers are working to help alleviate these problems by delivering improved rootstocks and varieties. The July issue of Citrus Industry magazine includes an in-depth look at this work. Read “Juice for Florida’s future” to …

ACP Detection Response: ‘The System Is Working’

Josh McGillCalifornia Corner, HLB Management, Pests

County and state officials in California have been actively responding to various Asian citrus psyllid (ACP) discoveries in the Central Valley in recent weeks. Kern, Tulare and Fresno counties have all reported an ACP detection over the last month. The Citrus Pest and Disease Prevention Division (CPDPD) has been implementing delimitation protocols and necessary treatment programs. CPDPD Director Victoria Hornbaker …

Use Physical Barriers for Root Health

Josh McGillIPCs, Root health, Tip of the Week

By Larry Duncan Citrus trees in Florida soils infested with diaprepes root weevil (Diaprepes abbreviatus) or sting nematode (Belonolaimus longicaudatus) frequently contend with devastating damage to their root systems. This is made even worse by root loss due to huanglongbing (HLB) disease. Where soil conditions are conducive to the insect or nematode, it is very difficult to prevent major economic …

Rotate Psyllid Products, Fundecitrus Urges

Josh McGillBrazil, HLB Management

Brazil’s Fundecitrus has launched the Insecticide Rotation Guide for Psyllid Control. Its aim is to help producers control the insect vector of citrus greening, highlighting the importance of proper rotation of products to avoid the selection of resistant psyllids. The resistance of insects and mites to pesticides can compromise the effectiveness of products and, consequently, the control of the pest …

Speeding the Search for an HLB Solution

Josh McGillHLB Management, Research, Varieties

By J. Scott Angle, jangle@ufl.edu, @IFAS_VP My hope is that your new citrus breeding team scientist will be a new Bill Castle on warp speed for an HLB solution. That is, John Chater will accelerate the search for citrus varieties that hold up against HLB. He’s got tens of thousands of places to search. Fred Gmitter and Jude Grosser have …

Grower and Researcher CUPS Collaboration

Josh McGillAll In For Citrus Podcast, CUPS, HLB Management

The spread of HLB in Florida citrus groves has forced growers and researchers to try all sorts of practices to fight off the disease’s devastating effects. One of the most successful methods has been planting citrus under protective screen (CUPS). The screen excludes the Asian citrus psyllid (ACP) and keeps HLB out of plantings. CUPS also is a great example …

HLB Research Priorities

Josh McGillAll In For Citrus Podcast, HLB Management, Research

Michael Rogers, director of the University of Florida of Institute of Food and Agricultural Sciences (UF/IFAS) Citrus Research and Education Center in Lake Alfred, discussed the recent Florida Citrus Growers’ Institute in the April All In For Citrus podcast. The event drew a good crowd of growers who came to learn about the latest research aimed at HLB. Rogers made …

CRDF Focused on HLB Therapeutics

Josh McGillCRDF, HLB Management

The Citrus Research and Development Foundation (CRDF) held its April board of directors meeting to hear reports on projects involving 2,4-D, gibberellic acid, brassinosteroids and zinc. According to Rick Dantzler, chief operating officer of CRDF, the foundation is conducting a full-court press to study how these materials can combat fruit drop and improve quality. CRDF staff also presented a proposal …

Products Proven to Help With HLB

Josh McGillHLB Management, Research

Researchers offered updates on products proven to help against the devastating citrus disease HLB in a virtual seminar on April 27. University of Florida Institute of Food and Agricultural Sciences horticulturists Tripti Vashisth and Fernando Alferez discussed the benefits of gibberellic acid (GA) and brassinosteroids, respectively. Vashisth reported that GA-treated Valencia orange trees dropped less fruit and increased fruit yields …