GREENING - ALSO KNOWN AS HLB  – 2005

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By far the most devastating event for Forida citrus growers took place in 2005 and is still having an industry changing impact in 2025!  August 2005 citrus greening was confirmed in Dade County!

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Citrus greening, or Huanglongbing (HLB), is a bacterial disease that has had a devastating effect on Florida's citrus industry since its arrival in 2005. The disease, spread by the Asian citrus psyllid (an insect smaller than a housefly), attacks the ‘plumbing’ system of citrus trees, causing a decline in health and, eventually, death. It has led to a major collapse of the state's citrus empire, reshaping the economy, landscape, and ecosystem. 

 

Origin and introduction: The bacteria causing citrus greening likely originated in Asia prior to the 1900s. It was first confirmed in Florida in Miami-Dade County in August 2005 and spread rapidly across the state. 

 

Rapid spread:

• Within a year, by June 2006, the disease was confirmed in 12 Florida counties.

• By 2009, greening had spread to most of Florida's traditional citrus-growing regions, including Central and Southwest Florida and the Indian River area.

• The spread was partly exacerbated by hurricanes that struck Florida in 2004, which, in addition to causing tree loss, helped spread citrus diseases. 

Failed mitigation efforts: Early attempts to manage the disease often involved insecticide applications and the costly removal of infected trees. However, the eradication strategy was largely abandoned because greening can exist in the tree for a considerable time before becoming active.  This made it impossible to identify and remove all infected trees. 

 

Impact on Florida

• Production decline: Since 2005, citrus production has plummeted. Orange production decreased by 92.5% and grapefruit production by 95.6% between the 2003–2004 season and the 2023–2024 season.

• Industry value and jobs: The total economic impact of Florida's citrus industry dropped from $9.29 billion in 2003–2004 to an estimated $2.8 billion in 2021. The industry has lost tens of thousands of jobs since greening took hold.

• Shift in global market: Florida, once a top global producer of citrus, particularly grapefruit, now produces less than one-tenth of its pre-greening volume. Major brands that relied exclusively with fruit from Florida now must import from other countries.

• Costs and prices: Remaining growers face higher production costs due to intense insecticide regimens and other treatments. These costs, combined with lower yields, have increased prices for consumers. 

• Tree health: The disease obstructs the phloem, the ‘plumbing’ system of the trees, which starves the roots and causes foliage to yellow. Trees produce misshapen, bitter, and unmarketable fruit before dying prematurely.

• Landscape transformation: The devastation has permanently altered Florida's landscape. Many growers have been forced to sell their properties to developers, resulting in the conversion of citrus groves to housing developments.

Research and future outlook

• Ongoing research: Scientists at the University of Florida and the U.S. Department of Agriculture (USDA) continue to research solutions.

• Current strategies: Growers utilize short-term solutions like nutritional supplements, bactericides, and mulch to slow the disease's progression.

• Long-term potential: Promising long-term solutions include developing disease-resistant citrus varieties through breeding and biotechnology, including gene-editing techniques. Some growers are experimenting with enclosed screen houses known as "Citrus Under Protective Screen" (CUPS) systems to prevent infection.

• Slow recovery: Despite progress, a definitive cure or widespread, economically viable solution for managing citrus greening does not yet exist. Recovery for the industry is expected to be a long and difficult process.