We moved to a new house this spring and inherited a lovely mature apple tree in the backyard. It's never been pruned and I set about doing both summer and winter pruning this year. Much to my horror (and panic) I just discovered a huge canker on one of the branches (right where it intersects with another branch), so it's essentially affecting two large branches. I have no idea what to do- it looks very severe and pruning it out will essentially mean removing both branches (and something like 1/3 of the whole tree). We still harvested loads of apples this autumn, so it's still fruiting, despite the canker. Any advice will be most gratefully received!