Hi Jeff
Hydroponic viticulture....wow!! For some reason this concept has never
occurred to me but what an interesting idea. Please keep letting us
know how this goes please Jeff. From the photos it seems you're doing
things pretty much as they should be, the vines look healthy. Last
season I had areas of the vineyard I was managing that had more non
fruiting shoots than other parts. After much discussion and
observation we decided it may well have been that they were lacking
some nutrients due to the soil type in that part of the vineyard. It
seems to me though that being hydroponically grown all your vines would
receive the same nutrients as the others, so perhaps for some reason
they are a little more stressed? Just a thought.
Are you keeping notes on what you are doing with the vines each time
you work on them? also, if you're not sure which is the best way to
treat them, then perhaps having a control group to compare with might
be a good idea. Even treating one vine differently may be enough to do
comparisons.
My thoughts on your shoot thinning are that opening up the canopy is a
good thing, especially if you have high humidty. It will help control
and show any powdery or botrytis problems.

Jerry,
Sounds like the season you are having is the season we've just finished
here in New Zealand. It was probably one of the most unpredictable
seasons we've every had. Taught us all a lot I think and made us think
out of the square, just as you are doing ie not bud rubbing the trunks
as often or as thoroughly as you may have other seasons. We shoot
thinned and then had to come through and lateral thin several times on
some of our blocks. We still had powdery mildew problems and now feel
we should have been more agressive with the lateral thinning. Next year
we intend to be but it will probably be a dry year with less growth,
just because we are prepared for the opposite.
This is a great discussion by the way. Always interesting to hear what
other viticulturists are up to. )