You should be pruning in late winter and you must leave some of last years wood in order to get fruit. If you prune off all of last years wood, you will get nothing. You can tell the difference between one yr and older wood by the color of the bark.

Remy: Thompson seedless are naturally small berries. What you are seeing is somewhere near the normal berry size of that cultivar. Commercial growers achieve larger berries by spraying gibberellic acid to first thin the fruit off each cluster and then to plump up the remaining berries. They also use other tricks like girdling the trunk. You could do this. It's not that hard. But it doesn't increase the flavor or sweetness and may do the opposite. Doing a better job of pruning, thinning, and other cultural tasks can increase berry size somewhat if they are limiting factors. Commercially berry size increase is used only for Thompsons destined for table grape use or other special applications like Jumbo raisins. The normal raisins are grown with small berries just like yours. So the vast majority of Thompsons are grown like yours with small berries.

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

It sounds like erineum mites. If so, only esthetic. But they won't go away if you ignore them. They're very tiny mites which over-winter underneath the bud scales