Smelling Huanglongbing for Early-Detection

Josh McGill Citrus Greening

Another early-detection method being developed works by smelling huanglongbing infections in trees. This method detects the different scents plants give off. Researchers at the University of California, Davis have created a test that could lead to advances in fighting huanglongbing (HLB) disease in citrus. Researcher and professor of mechanical and aerospace engineering, Christina Davis, said the test looks for a …

Groundcovers Promote Water-Use Efficiency and Pest Management

Jim Rogers Irrigation, Pests

By Sandra M. Guzmán, Larry Duncan, John Santiago and Lorenzo Rossi The implementation of pest management technologies might have an impact on other management areas in the grove. Landscape fabric groundcovers, for example, have been used for pest management in citrus production. Groundcovers also recently have been used to promote the homogeneous availability of water for uptake by roots, better …

Citrus Breeding Discussed During Field Day

Jim Rogers Breeding, CUPS, Fresh

The focus of citrus breeding at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) differs for fruit produced for the juice market vs. fruit for the fresh market. Citrus breeder Jude Grosser, a UF/IFAS professor of plant cell genetics, spoke during the Cold-Hardy Citrus Field Day at the North Florida Research and Education Center in Quincy on …

Cold-Hardy Citrus Research Initiatives

Jim Rogers Cold Hardy, Research

The Fruit Crop Physiology Lab at the North Florida Research and Education Center (NFREC) in Quincy is focused on developing a sustainable and profitable cold-hardy citrus industry in the southern United States. To do that, it is conducting research-driven Extension projects. The NFREC is part of the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS). The lab collaborates …

Evolution of Sting Nematode Integrated Pest Management

Jim Rogers Pests, Research

By Homan Regmi, Larry Duncan and Johan Desaeger Two field trials were initiated in a Polk County, Florida, commercial grove of 15-month-old Valencia on Kuharske trees in 2019 to measure the effectiveness of integrated pest management (IPM) tactics for managing sting nematodes (Belonolaimus longicaudatus). Six chemical nematicides, many newly released, were compared in one trial. In the second, perennial peanut …

Quality Aspects of Citrus Juices

Jim Rogers Orange Juice

By Renée Goodrich and Charles Sims In this era of huanglongbing (HLB), almost every scientific and popular press article alludes to HLB’s impact on fruit and juice quality. The citrus industry uses the term “high-quality” to denote a fruit, product or byproduct that has an array of positive, expected and measurable attributes. Consumers also use terms referring to quality, but …

Canker Resistance Progress May Help With HLB

Jim Rogers Breeding, Diseases

A team of researchers at the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) has successfully identified the CsDMR6 gene, which impacts a citrus tree’s reaction to the citrus canker pathogen. Zhanao Deng and Fred Gmitter, both professors and plant breeders, are members of that team.  By editing the CsDMR6 gene in the plant’s DNA to interfere with …

CUPS Update From the Citrus Research and Education Center

Jim Rogers CUPS, HLB Management, Research

By Arnold Schumann, Laura Waldo, Chris Oswalt, Napoleon Mariner, Timothy Ebert, Perseveranca Mungofa, Shankar Shrestha and Laura Cano-Castro Florida grapefruit production for the 2021–22 season was 92% less than in 2003–04, which was prior to the arrival of huanglongbing (HLB) disease [Source: U.S. Department of Agriculture National Agricultural Statistics Service, (USDA NASS)]. The decrease in Florida tangerine production for the …

Pest Incidence and Management in CUPS

Jim Rogers CUPS, Pests, Research

By Jawwad A. Qureshi and Salman Al-Shami The citrus under protective screen (CUPS, Figure 1) system is designed so citrus can grow inside screened enclosures to protect it from huanglongbing (HLB) and the Asian citrus psyllid (ACP, Diaphorina citri). ACP is the primary vector of the pathogen responsible for causing HLB, known as citrus greening disease. This vector-pathogen combination is …

CRDF Reviews Audit and Analyzes Budget

Jim Rogers CRDF, Research

The Citrus Research and Development Foundation (CRDF) board of directors gathered for its August meeting. Its first order of business was a review of an auditor’s report. “I’m pleased to report there were no findings. A clean audit is always good news,” said Rick Dantzler, chief operating officer of CRDF. The board dedicated time to the budget, analyzing funds available …

California CRaFT Project Targets Psyllids

Jim Rogers California Corner, Psyllids, Research

All commercial citrus producers in California are invited to apply for participation in the Citrus Research Board’s (CRB) California-focused Citrus Research and Field Trials (CA-CRaFT) project. The overarching goal of CA-CRaFT is to demonstrate the effects of additional mitigations on Asian citrus psyllid control within commercial citrus groves across the various citrus-growing regions in California. The project is supported by …

Liberibacter Relative Mutating Rapidly

Jim Rogers Brazil, Diseases

A bacterial species closely related to citrus greening disease is rapidly evolving its ability to infect insect hosts and possibly plants. The newly identified species belongs to Liberibacter, a family of bacteria known to infect several economically important crops. There are nine known Liberibacter species, including three that are associated with citrus greening.  Citrus greening, also known as huanglongbing or …

Impact of HLB on Fruit Growth and Retention

Jim Rogers Fruit Drop, HLB Management

By Tripti Vashisth and Mary Sutton Citrus trees affected by huanglongbing (HLB) consistently have small fruit and low fruit numbers at harvest. The low fruit numbers are largely attributed to the increased rates of preharvest fruit drop that accompany HLB. Small fruit is more likely to drop during this preharvest period, suggesting a link between fruit size and retention. To …

California Growers Show Strong Support for Citrus Research Board

Jim Rogers California Corner, Research

California citrus growers recently voted by a large margin to continue their support of the Citrus Research Board (CRB) in a state-mandated referendum. The recently concluded referendum, which must be held every five years, was conducted by the California Department of Food and Agriculture (CDFA). A majority of eligible citrus producers voted in the referendum. Their support was nearly unanimous …

California HLB Quarantine Areas Expanded

Jim Rogers California 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 …

Kaolin Clay

Second CLas-Positive Psyllid Sample Found in California Grove

Jim Rogers California 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 …

ACP Detection Response: ‘The System Is Working’

Jim Rogers California 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

Jim Rogers IPCs, 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 …

High Summer Temperatures Take a Toll on Trees

Jim Rogers Research, Weather

By Anirban Guha and Christopher Vincent A quick body temperature test is common these days before entering many workplaces, hospitals and clinics due to the ongoing COVID-19 pandemic. The purpose is to screen people for fevers, usually with a non-contact infrared thermometer. Measurement of plant body temperatures also has become common for many field crops, not to screen for infectious …