Couple months ago I chopped my 5ft tall Valencia Pride down to 1ft when I found it had the "dark wood" disease: the center hardwood had dark brown stain and the surrounding bark was watery rot. I kept cutting down the trunk until the wood was clear from stain. But it seems I didn�t cut down far enough and this morning I found the same disease with upper branch dying off, so I cut it again and burning the knife blade after every cut. Well, here all it left with about 1.5" above the graft line (black color tree wound compound). Should I keep the stump in shade or out in normal sunlight in hope that I could recover? What is the right way to deal with this disease?

Sapote