I have this pre trained Japanese maple and I’ve come to notice over this season a discoloration in one of the primary branches, any help on what this might be and if it should be of any major concern ?
David - Welcome to the forum. It is hard to tell from the picture if this is a problem or just some bark damage. How does the rest of the branch look? Worst case is that it has one of the vascular fungal diseases which are hard to control.