RE: Old apple tree questions
Apple trees in centeral Ontario need to be Pruned the end of March /first of April. As advised above and aswell as any suckers that are growing wild(into other parts of the branches) Suckers are new growth that grow straight up off the branch. You can leave the ones that look as if they are going to grow out to an opening and fill the tree top. Most of the center of the tree needs to come out. This will allow more light to the inside of the tree. When finished the tree will look badly open , but will regrow proper.
Large fertiliser spikes can be drove in around the tree keeping them around 8-10 feet from trunk. This will also help the tree to produce.
Hope that helps...BT