I have a mature peach tree in my backyard of the house I purchased last year. We began occupying the house in June of last year, and the tree produced a lot of peaches (100-200) which we were able to enjoy during their ripened phase in August despite several succumbing to pests and deer. As spring approaches, I plan to prune this free extensively as It has a lot of overgrowth and lacks an open canopy that is recommended for this type of tree. I also plan to add a layer of mulch at the base. However, I am fearful that this tree is past it’s prime as the base of the trunk doesn’t appear to be in good shape (see picture) and at least two of the large, scaffolded limbs are plagued by gummosis. Unfortunately, the previous owner didn’t take care of it well and I am pretty certain to pruning has happened in at least a couple years. Any recommendations on how to best prune this tree, keep pests away, and increase its life span would be much appreciated.