Citrus greening disease

Citrus greening disease is a deadly disease of citrus fruits.

Also known as:
Huanglongbing disease

recognize symptoms Citrus greening disease
Symptoms Citrus greening disease on lemon, photo: U.S. Department of Agriculture - CC BY-ND 2.0

Citrus greening disease is a deadly disease of citrus trees. Citrus greening disease is caused by bacteria of the Liberibacter strain. In Asia, Citrus greening disease is transmitted by the Asian citrus psyllid (Diaphorina citri) and in Africa by the African citrus psyllid (Trioza erytreae). Infection causes the leaf veins to yellow, then the yellowing spreads over the entire leaf. Leaves fall early, twigs die and roots rot. The tree weakens and eventually dies.
The fruits of infected trees remain small, irregular in shape and have a thick skin, which remains green from the branch. The fruits are bitter in taste.
Citrus greening disease occurs in tropical and subtropical regions, especially Asia and Africa. The disease is also prevalent in America. In Australia and the subtropical regions around the Mediterranean Sea, the disease does not occur.
The economic damage caused by Citrus greening disease is great.

Where to find

  • Lemon, mandarin, orange, grapefruit, limes and pomelo trees (Citrus)


After infection, recovery is not possible. A suitable antibiotic is being researched.


There are no known preventive measures. It is being investigated whether genetically engineered varieties could provide a solution.