A couple of thoughts (Grapeman is the expert, but I have grown both Baco and Seyval) As soon as you see positive growth, cut back to one or two buds. On the fertilizer, I would not add Nitrogen unless a soil test indicates it. Over fertilizing a variety like Baco which is a prolific grower will lead to all tops and weak grapes for years. I simple soil test will tell you. Clay can be pretty deficient, but I pays to know for sure. Any garden center or university can do it for you.