Originally Posted by ctheis
The big effect was that all the growth that came through were shoots directly off the crown...ok so we strung the most vigourous shoots and up the string they went...for a while...we then noticed that new rhizome growth had protruded from the edges of the beds and they looked very strong so we strung those. This has happened across all varieites whether transplanted this year or not. All the shoots we trained that were directly from the crown are by far the weakest and all the growth that had protruded from under the plastic ar by far the strongest. The difference is quite noticeable even to someone that has never seen hops before.
Finally got around to reading your research effort synopsis and I think you may have answered your own question.
I would surmise that you do some sort of 'pruning' to keep your plants from spreading too much. If that is so, you should have some pretty well behaved crowns. On crowns that have been pruned of stray rhizomes there are still plenty of buds left on the crown that will send up new growth. The ones closer to the surface will obviously come up first and the deeper ones will emerge later. If you put a barrier around the crown (like you say you did), the deeper buds will try to send up shoots but will run into the barrier and travel the path of least resistance which would probably be the ones that squirted out of the ends of your barrier. This "second growth" is what the hop producers use to produce their crop. I knock the first growth off because I'm usually pretty busy at that time of the year and sometimes have to whack off the second round of growth until I have time to train them.
Like I said, if you prune up your crowns in the early spring (late winter in your case) your research answered your question. If you don't prune your crowns . . . well, forget what I just said in my reply and keep on keepin' on!