Citrus greening, also called Huanglongbing or yellow dragon disease, is a bacterial disease that attacks the cascular system of plants. Once infected, there is no cure and can cause citrus trees to produce bitter and inedible fruit. Information from Fresh From Florida.

DISEASE SYMPTOMS

  • Yellow shoots
  • Mottled leaves
  • Small fruit with poor juice quality

CAUSAL AGENT

In Florida, the disease is associated with Candidatus Liberibacter asiaticus, a bacterium that has not yet been cultured in the laboratory. In other parts of the world, this is disease is associated with Candidatus L. americanus and Candidatus L. africanus and may be spread by psyllids, which are insects that feed on plant juice.

HOST RANGE

  • Several citrus species

GEOGRAPHIC DISTRIBUTION

As of December 2005, this disease has been detected in eight counties in south Florida.

SPREAD of the PATHOGEN and CONTROL OPTIONS

In Florida, this disease is spread by an insect (a psyllid, Diaphorina citri) and is spread by this and other psyllids. In other countries it is controlled by eliminating infected trees and treating the psyllids with insecticides.

More Resources