Trunk Peeling on an Orange Tree

Exocortis

• New regulations regarding rootstocks lessened the chance of young trees being infected with exocortis, but older trees can still show symptoms. This virus is not aggressive. It causes stunting and diminished productivity in time. Peeling and shelling bark below the graft union is the virus’ most obvious symptom.

Psorosis

• Commonly found on older trees, psorosis causes stunting and slow decline. Branches, limbs, twigs and trunk bark above the graft union show wartlike protuberances that burst to peeling, flaky bark. Gummosis is possible around peeling bark and in later stages gummy sap can clog and kill sapwood.

Xyloporosis

• Also called cachexia, this virus causes pitting in bark near the graft union. Pitting is often severe and leads to bleeding sap and peeling bark. Tangerines and tangerine hybrids like the Orlando tangelo are the most susceptible. Stunting and severely diminished production are common symptoms of xyloporosis.

Control

• Viruses are incurable. Don't take any grafts from the tree or your new trees are also infected. In home orchards where production is less an issue, these viruses may not be worth worrying about. Keep an eye on the trees to ensure they don't become a hazard as they decline. If you are unable to live with the peeling bark and poor production, remove and replace your tree with a resistant variety.