Citrus Greening Disease
Citrus Greening Disease is the latest threat to Florida agriculture and homeowner fruit. Whereas Citrus Canker eradication efforts by the state ($500 million so far) have already destroyed over 4,000,000 trees, this disease is far worse because the infection kills trees
According to a release by the (Florida) Division of Plant Industry, "Citrus Greening Disease or huanglongbing (yellow dragon disease) may be the most serious citrus disease in the world."
Citrus Greening Disease is caused by a bacterium yet unnamed. Proposed names include Liberibacter, also seen as Candidatus Liberibacter. Citrus Greening Disease is spread by insects; Citrus psyllid. There are both African and Asian strains of the disease as well as one American
"This is as bad as it gets" said Nathaniel Roberts, general manager of a 4,000-acre Florida grove
The Sun-Sentinel also reported 10-13-2005 that Richard Miranda, spokesman for the Florida Department of Agriculture, that there is no cure for citrus greening; Infected trees must be cut down. Among the options to stop citrus greening is the use of pesticides, which he said would be applied only on commercial groves, never in residential areas
On January 2, 2013, The Wall Street Journal updated the information with no good news saying, "Disease Rips Through Florida Citrus"
Known as "Yellow Dragon Disease" in China, citrus greening is found throughout east Asia as well as Brazil, #1 in the world for citrus production. Citrus greening has also infected Saudi Arabia and India
The name "Greening" comes from the fact that Citrus Greening Disease causes trees to produce predominantly greened (worthless) fruit which fails to ripen as well as inducing a bitter-salty flavor when processed
Symptoms include stunted root growth and premature fruit drop then, in time, tree death
Citrus Greening Disease is now confirmed present in one half of all commercial citrus growing counties in Florida. Dean Gabriel, a citrus researcher at the University of Florida said, "I lay the blame on citrus producers for not being more concerned. They were told it was coming. Now they're paying attention, but it may be too late."
How citrus greening got to Florida is unknown. There are two varieties: one from Asia and one from Africa
Unlike Citrus Canker, Citrus Greening kills trees
Citrus Greening is probably the most serious of all afflictions of the citrus species
According to the University of Florida, "The Asian citrus psyllid (AsCP), Diaphorina citri Kuwayama, was first detected in Florida by Susan Halbert on June 2, 1998. This exotic insect is not now regarded as a major pest in and of itself; however, it is the vector of a serious bacterial diseasecalled citrus greening (CGD) (Liberobacter spp.). In Asia, the major pathogenis L. asiaticum. AsCP could be the most serious pest of citrus in Floridaif the bacterium causing CGD is also present."
The Florida Department of Agriculture press release dated 09-02-2005 is here
Citrus Greening article by Ann Henson
Citrus Greening article by Robert Bowden
Citrus Greening article by David Fleshler
Pictures of affected trees, insects and fruit