This tree has canker disease. Sooty canker is a tree disease that afflicts trees in warm, dry climates, such as Las Vegas. This incurable fungal disease causes lesions in the bark of trees, mostly in the branches but can also be present in the trunk. Tree sap forms into hard balls that will stretch the bark causing it to burst. Once the bark bursts, the tree is exposed and is vulnerable to other pest infestations and diseases. Other signs of Canker disease are: 

• Brown leaves
• Wilted leaves
• Smaller than normal leaves
• Appearance of “soot” on the branches
• Cracking or peeling bark 

Improper pruning techniques can also leave your trees at risk to attract the disease. Prevention is the best course of treatment. Proper tree care, such as regular pruning, fertilization and adequate watering will keep your trees healthy and is less likely to attract these types of diseases. If your trees exhibit any of these warning signs or do not look their healthiest, contact our office to have one of certified arborist assess the health of your trees.