Canker On Trees

[taylor13]

a light green growth has appeared on the bark of quite a number of trees in my garden - hawthorn -apple -pear . I have found a picture on line which indicates that it is canker. Hoowever, I have not been able to find any advice on what to do about it - nor how to get rid of it. Can you help?

[Chipchopper]

Are you sure it's bacterial canker "Light green growths" dont sound like it to me.

Normally a discoloration of the bark, usually brown or blackish-grey