The bottom picture I would say is almost certainly black rot. Use Google image search and compare the pictures you find there. Those little black spots are benign in some varieties, my Chambourcin always has them. Or maybe they are small spots of black rot? I don't know about the leaf curling, many things can do that. I would look carefully for signs of bugs or other disease -- leafhoppers and powdery mildew are two potential causes of leaf curl. What have you been spraying? Those grapes are vinafera types and are not disease-resistant at all. I spray my vinafera every week this time of year. Black rot is one of the worst grape diseases, it will cause all of the fruit to rot. If you don't have a regular spray program you need to do some research and set one up. Or pull those varieties and try some more disease-resistant ones. Scott

Probably grape phylloxra. Link to pictures: https://www.google.com/search?q=grape+phylloxera+pictures&client=firefox&hs=BVB&rls=com.yahoo:en-US:official&tbm=isch&tbo=u&source=univ&sa=X&ei=yiuqUZLtNsXT0wGSkoGYCw&ved=0CDIQsAQ&biw=1280&bih=610 Here is a link that might be useful: grape phylloxera management This post was edited by fruitnut on Sat, Jun 1, 13 at 13:22

This is a fun little experiment so definitely keep us posted. I think we're all learning something here. :) Rooting under glass in this case, to me, means cutting a short section of stem, sticking it either in to a pot of good potting soil, or sticking it in to the ground, and then watering well and either covering the cutting/stem with a bell jar, glass, or plastic bag etc to make a mini-greenhouse. If you have 14 feet to work with, yes "mixing it up" would mean hacking it in to smaller pieces and trying different strategies. If it was mine, I'd cut it in to 12 inch sections (keeping track of which end was pointed to the original roots and which was pointed to the branch tip) and I'd try different strategies: rooting in water indoors, rooting in water outdoors, rooting in potting soil indoors, rooting in potting soil outdoors (covered), sticking some in soil outdoors (maybe some with, or some without, the little greenhouses), and so on, just to improve your chances for success. I bet you'll get some success from one of these methods. I wouldn't add manure etc to the soil where you're rooting them--sometings that can encourage rot or burn etc. I'm sure they'll love it once they're rooted and you're ready to plant them to their new permanent home. Keep the updates coming as I'd love to know what method succeeds for you since I've always rooted only dormant stems (and quite lazily at that with a gentle shove of the stem in to the ground or potting soil in winter). Take care and super good luck! Grant

Knowing how much is a "gentle tug" will require some experience. As you gain this "experience" by trial and error you will pull a few that are not rooted. When this happens, you can just put the cutting back, and give it more time, you have not in most cases done any harm. Al