I might consider topping that central stalk to the first node and let it branch out so that it isn't so tall and lanky. Typically, I prune fruit trees in the winter or early spring. I trim off any branches that are crossing, low sucker branches especially ones below a graft line and if there are Y shaped branches, trim off the inner portion of the Y so that it's always growing upwards and outwards. This will open up the fruit tree in the center and allow more air exchange and sunlight to penetrate the center of the tree. Try to prune branches off as flush with the trunks as you can. Also remove any dried out dead branches and old leaves.