I have a fruit tree whose primary trunk is pomelo fruit and the grafted trunk is Lemon. It's a reasonably large tree (35ft as a guess).
I don't much like the pomelo fruit and don't really eat them. I can't really reach the whole tree, so the fruit drops off and makes a bit of a mess. I get out there and clean up the dropped fruit on the weekends, but it attracts rodents and such as well. All around, a little more annoying than beneficial.
On the other hand, I love the lemons and would hate to lose them. Planting a new lemon-only tree would presumably take a long time to reach the size of this current tree.
How aggressively can I prune the pomelo branches without killing the lemon? Will the lemon be able to support the root/trunk of the tree if I cut back the pomelo completely? Added photo. The left hand 'trunk' is the lemon and the more vertical larger trunk is the pomelo.