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. The yellowing spreads, and trees decline and die.
- Yellow shoots
- Mottled leaves
- Small fruit with poor juice quality
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.
Citrus species, and several other planbs that host the bacterium.
Citrus greening is present in all Florida counties with commercial citrus groves and has been found in other states including Texas and California. It is present in many citrus-producing counties in Asia, Latin America, and Africa.
SPREAD of the PATHOGEN and CONTROL OPTIONS
In Florida, this pathogen is pimarily spread from tree to tree by the Asican citrus psyllid (Diaphorina citri), a small insect, but can also be transmitted by grafting. Currently, spread of the disease is conrolled by insecticides. Novel methods to maintain health of infected trees and to prevent new infections are areas of of active research at the University of Florida.
- “Citrus Diseases Exotic to Florida”
- “Citrus Greening – Another Threat to Agriculture”
- Resources and Information – Citrus Research & Education Center (IFAS)
- UF/IFAS Extension – Citrus Greening
- UF/IFAS News – Citrus Greening
- USDA APHIS
- Florida Department of Agriculture
Information from Fresh From Florida and by Erica Goss, EPI and UF/IFAS Department of Plant Pathology.