Keith Pegg said: My Director of Golf went to the PGA show and one of the classes or seminars he attended, they were told to have the "grounds staff" remove all greens liners on sand greens as they were a major problem with sand based greens today. This goes against everything I have ever learned in 40 years of experience with sand/USGA greens. If anyone can send me a comment on who gave this talk I would like to contact him, to find out more details on what was said and why.
I have built (supervised the construction) of over 200 greens and back in the 70's did build some without a plastic ring (I was an Assistant at that time) and had a number of problems with dry edges on the sand and wet spots in the fringe. I would bet that these have been added if the greens are still even still there.
I welcome any and all comments on this subject.
Keith Pegg
Zama Golf Japan 
Keith,
I "hope" this speaker explained his comments. A liner is installed to prevent wicking from the sand root zone into the, I'm assuming, tighter outside soil. There is NO other purpose for it. It does NOT prevent encroachment from other grass species. It DOES prevent the pulling of moisture from a coarser zone into a tighter zone. Admittedly, I have built courses that were pure sand, wall to wall. In that case, the characteristics of the profiles defined my decisions on the need for a liner....or barrier.
Even with the barrier, problems with dry putting surfaces occur because of construction procedures. The greens are rolled to settle the root zone. Unfortunately, some operators tend to come up close to the edge, then back off, thinking that they have settled the entire putting surface. It's this last half meter or so that doesn't get the same compaction, or settling, that the rest of the putting surface receives. Water settles, but mechanical settling is needed as well.
This is a common mistake that I have seen on hundreds, and hundreds of greens. They're attempting to be careful at the perimeter, but the result is a different profile. A softer profile around the perimeter obviously changes the infiltration and percolation rate. I understand the "caution", but the entire root zone needs to be equal in compression, or you have two different profiles.
I do not understand his comment about liners being a major problem with sand based greens. Whether it is sand to sand, or sand to clay, how can a "problem" be caused? If the particle size of the green root zone is close to, or even identical to, the core surrounds, then money may have been wasted on the liner. That would be the only problem...period. But that is rarely the case. Advocating "ripping out" the barrier is an absurd proposal. It's installed! Leave it.
If the architect, or contractor, realizes in advance that the both materials are almost identical, then the barrier can be eliminated. But removing it after the fact? A complete waste of labor, time, and the resulting cost.
Again....ensuring that the ENTIRE putting surface is compacted, or settled equally, will eliminate the problems of dry putting surface edges, and wet surrounds. I have no idea who this speaker was, but an explanation of soil properties should have been included in his presentation.
That may have been a too complex explanation that would not have been understood by certain people in management, but it should have been given. That now gives you the opportunity to decipher the language.
I have no doubt you have the ability to do just that.