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Citrus Greening Portal

What is Huanglongbing or Citrus Greening?

Huanglongbing (HLB), also known as citrus greening, poses the most serious threat that the Florida citrus industry has ever faced. The bacteria that cause citrus greening - three species of Liberibacter – most likely originated in Asia prior to 1900 and has slowly spread throughout the world in many citrus growing areas. In countries where the disease is endemic, different varieties of citrus trees like “sweet orange” begin to decline within 3-4 years after planting, resulting in reduced fruit crop and fruit quality.

Citrus Greening FAQs

Citrus greening was first detected in Florida in 2005. By 2008, it had been identified in most of the citrus growing counties in the state. Despite intense efforts, citrus greening now threatens the survival of Florida citrus, has a toehold in other citrus areas, and poses a threat to the entire U.S. citrus industry.

What Are We Doing to Control Citrus Greening?

ARS scientists across the country are actively engaged in research with university and industry partners on all aspects of this disease problem, including the host, pathogen, and insect vector. We are making great progress in not only understanding how citrus greening infiltrates healthy citrus trees, but how to protect these trees from the disease. Our goal is to overcome citrus greening and ensure the U.S. citrus industry can provide consumers with tasty, high quality citrus fruits for years to come.

Watch Our Citrus Greening Research in Action:

Check Out Our Latest Research On Citrus Greening

Citrus Greening: Is the End in Sight?

Researchers are boosting the citrus tree immune system.

A dog detecting citrus greening in a grove
Canines Detect Citrus Greening

Specially trained canines may be used to detect citrus greening in orchards.

Leaves with symptoms of citrus greening.
Beating a Citrus Grove Enemy

ARS scientists in Florida are studying the effectiveness of two new antibacterial spray treatments that show promise for improving tree health.

Distinguishing Jekyll from Hyde in Citrus Disease

Researchers found a way to distinguish between two citrus diseases that are similar in appearance, but dangerously different.

How to Save the Florida Citrus Industry?

ARS researchers find answers in the unique biology of the ocean.

Speeding Push for HLB-Tolerant Citrus

Genetic discovery could speed the search for hybrid citrus trees that tolerate citrus greening disease and produce fruit ideal for making juice.

Guarding Against Citrus Greening

Researchers are developing new strategies to combat citrus greening, including an improved diagnostic test to detect the bacterium.