Citrus Variegated Chlorosis
Citrus Variegated Chlorosis or CVC is a disease of citrus caused by the xylem limited bacterial pathogen Xylella fastidiosa . CVC is not present in the United States…yet. The disease has caused considerable crop loss in Brazil and has also been found in Argentina. Sweet oranges are more susceptible than grapefruit.
Citrus is not the only host for the Xylella fastidiosa. Some reading this may have heard of Pierce’s Disease, which is a major concern of the California grape industry. Pierce’s disease is caused by a different subspecies of Xylella fastidiosa. In Brazil, coffee is also affected by Xylella fastidiosa.
CVC is spread by insects known as a sharpshooters or leafhoppers. The sharpshooters like to feed on a variety of plants, and the pathogen can also grow in a variety of plants, which is how the pathogen is spread from crop to crop.
The symptoms of CVC include a bright leaf mottle in citrus. An infected citrus tree also produces fruit which are very small and because they contain very little juice they are very hard and can damage commercial juicing machinery (photo courtesy R. Brlansky-UFL). In the greenhouse we have observed if the plants are watered, fertilized and grown optimally the plants are healthy in appearance and symptomless. We do not grow our citrus plants large enough in our greenhouse to produce fruit. Environmental stress may play a large role in symptom expression.
Sharpshooters and Pierce’s disease are found in Florida but so far no CVC disease has been found. As with all other pathogens of citrus it will likely be introduced by someone carrying in budwood from an infected tree.
For more information about citrus pathogens please contact Dr. John Hartung
For more information concerning growing citrus please contact Cristina Paul