Question
We have a 5 year old plum tree that has developed small raised bumps on the trunk and some branches.  The bumps are fairly soft, and easily scrape off, leaving a missing bit of bark.  Is this a disease, or a normal process?

Answer
It is not disease, but rather sounds like scale insects.  These insects are oval shaped and slightly raised.  They do not move while feeding.  They can suck the tree dry if left uncontrolled.  Depending on whether the fruit is edible or not will determine your course of action.  They do need to be treated with an insecticide.  Find a product for your particular situation and treat ASAP.  If you need more assistance, please feel free to contact me again.  Good Luck.