So this is a whip plum I am growing into an espalier, first year in the ground from a small whip.
I’ve read about removing gall affected branches in winter, but this is the trunk of the little tree.
Cut it off flush to the tree trunk and paint?
Right or wrong I wouldn’t resist cutting it off. That should be the best choice. Leaving it doesn’t seem right.
Looks like a spider… or a big ant on the gall.
Good luck on getting that off.
So just spoken with my local Ag center horticulturalist and he said since the tree is so small just leave it. The only thing it might affect is vigor and this is a tree I’m training on espalier so I don’t need vigor.
In fact this tree has almost grown the two branches I need to complete the form in just a few months.
Belgian fence form.