Silicon Being Evaluated for North Florida Citrus

Jim Rogers Cold Hardy, Diseases, Nutrition

The element silicon, known to be beneficial to many plants, is being evaluated for advantageous effects on North Florida citrus and blackberries. Horticulturist Muhammad Shahid discussed the benefits of Earth’s second-most-abundant element (after oxygen) during a recent Cold-Tolerant Citrus Production Workshop in Perry, Florida. Shahid is a University of Florida Institute of Food and Agricultural Sciences assistant professor at the …

Post-Hurricane Disease Management Advice

Jim Rogers All In For Citrus Podcast, Diseases

Megan Dewdney, associate professor of plant pathology with the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS), joined the October All In For Citrus podcast to discuss Hurricane Ian and tips on disease management after the storm. Hurricanes weaken citrus trees and spread disease.  “If a tree has a full canopy, the wind will put a lot of …

Phytophthora Treatments for Hurricane-Damaged Groves

Jim Rogers Diseases, hurricane, Tip of the Week

By Megan Dewdney A priority for the Florida citrus industry is evaluating groves for damage and determining the best course of action going forward after the destruction of Hurricane Ian. One of the many considerations is the effect of flooding on root health, particularly if standing water has remained longer than 72 hours. The main diseases are phytophthora foot, crown …

Preventing Further Hurricane Damage in Groves

Jim Rogers Diseases, hurricane, Pests

University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) faculty recommend actions citrus growers can take to prevent further damage to root systems and future fruit drop following Hurricane Ian. DEAL WITH PHYTOPHTHORAIf standing water has occurred in groves with phytophthora problems, growers should evaluate for root damage and treat accordingly. Floodwaters resulting from heavy rains can severely impact …

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 …

HLB and Canker Incidence Increasing in Brazil

Jim Rogers Brazil, Diseases

The average incidence of HLB rose from 22.37% in 2021 to 24.42% in 2022 in Brazil’s citrus belt, an annual survey by Fundecitrus shows. That’s an increase of 9.16%. In the regions of Brotas, Limeira and Porto Ferreira, where the incidence was already high in previous years, HLB increased to even more worrying levels of 49.41%, 70.72% and 74.05%, respectively. …

How Different Techniques Hold Up to Diseases

Jim Rogers Citrus Expo, Diseases, IPCs

How well reflective mulch, kaolin clay and individual protective covers (IPCs) hold up to HLB, canker and greasy spot diseases was researcher Megan Dewdney’s topic at the 2022 Citrus & Specialty Crop Expo. Dewdney is a University of Florida Institute of Food and Agricultural Sciences associate professor of plant pathology at the Citrus Research and Education Center.  The research project …

California Seeks Funding for CYVCV Disease

Jim Rogers California Corner, Diseases

With citrus industry backing, California state legislators have requested $2.5 million in emergency state funds to help prevent the spread of citrus yellow vein clearing virus (CYVCV). The first finding of the new disease in the United Sates was recently made in Tulare, California. Casey Creamer, California Citrus Mutual (CCM) president and chief executive officer, said the statewide grower organization …

Reminders on Requirements for Fruit Movement

Jim Rogers Diseases, Fresh, Regulation

Florida’s fresh citrus industry was recently reminded of federal requirements for movement of fruit from some disease quarantine areas to contiguous states and to the European Union (EU). The reminders came from Paul Mears with the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) during Citrus Packinghouse Day. Mears is the Florida Citrus Health Response Program (CHRP) …

Controlling Diplodia SER on Grapefruit

Jim Rogers Diseases, Grapefruit

Studies that show some potential for control of Diplodia stem-end rot (SER) on fresh grapefruit were discussed at the recent Citrus Packinghouse Day. University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) researcher Mark Ritenour made the presentation. Ritenour works as a professor of postharvest physiology and management at the Indian River Research and Education Center in Fort Pierce. …

Florida Black Spot Quarantine Expanded

Jim Rogers Diseases, Florida, Regulation

Federal and state agriculture officials have expanded the citrus black spot (CBS) quarantine area in Florida. They have added four sections in Collier County and five sections in Glades County. The action was taken by the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) in cooperation with the Florida Department of Agriculture and Consumer Services Division of …

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 …

Greening and Canker Concerns for Georgia Growers

Jim Rogers Diseases, Georgia

The recent Citrus Growers’ Summer Update in Valdosta, Georgia, provided growers another outlet to learn about two diseases — citrus greening and citrus canker — that could have serious ramifications on the industry’s future in Georgia. Jonathan Oliver, University of Georgia (UGA) assistant professor and small fruits pathologist, highlighted the seriousness of the discovery of both of the diseases in …

First U.S. Detection of Citrus Yellow Vein Clearing Virus

Jim Rogers California Corner, Diseases

The first detection of citrus yellow vein clearing virus (CYVCV) has been made in Tulare, California. The disease was detected during the California Department of Food and Agriculture’s (CDFA) routine multi-pest survey. The U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) has confirmed positive identifications of the disease. CDFA is surveying for the disease in Tulare County …

Citrus Canker Quarantine Established in Alabama

Jim Rogers Diseases, Regulation

Federal and Alabama agriculture authorities recently established a citrus canker quarantine for all of Baldwin County, Alabama, to prevent the spread of the disease. The quarantine was established on July 25 by the U.S. Department of Agriculture’s (USDA) Animal and Plant Health Inspection Service (APHIS) and the Alabama Department of Agriculture and Industries (ADAI). On June 22, 2021, APHIS confirmed …

Leprosis Management Recommendations for Brazil

Jim Rogers Brazil, Diseases

Fundecitrus recently issued recommendations for leprosis management in Brazil. Leprosis has been expanding in the Brazilian citrus belt for the last six years and is an increasingly significant cause of fruit drop. The disease also causes a reduction in the useful life of the tree, weakened by defoliation and drying of the branches. The main disease management strategy is to …

Sweet Orange Scab Regulations Modified

Jim Rogers Diseases, Regulation

The conditions under which citrus fruit may be moved interstate from areas quarantined for sweet orange scab (SOS) when destined for processing or packing in a commercial citrus-producing state without a statewide SOS quarantine have been modified. The modification was made by the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (USDA APHIS). In 2010, APHIS published Federal …

Keep CTV Under Control

Jim Rogers Diseases, Tip of the Week

By Amit Levy Citrus tristeza virus (CTV) infects the citrus phloem. CTV infects almost all citrus varieties, but it causes different disease symptoms depending on the virus isolate, the citrus variety and scion-rootstock combination. Florida has three dominant strains of CTV: T36, a decline-causing strain T30, which normally does not cause severe disease VT, a stem-pitting causing strain CTV is …