I have a dogwood that was transplanted about 15 years ago when it was very small. It is now about 12 feet with good limbs and green leaves at the top. From the bottom of the trunk up about 4 to 5 feet it appears to be some type of scale or fungus. Is there something I could spray it with to help it. It has been in full sun the entire time. Thank you
This appears to simply be Lichen that is on the trunk of the tree.
This is generally harmless, and it may have been on the trunk from it's previous planting area, if it was shady.
Here is an article that discusses this.