Mark,
I believe the ethylene molecule is too large to penetrate (polyethylene)
storage bags. I say "I believe" because I haven't actually studied the
matter and I have kept scionwood in my refrigerator (along with fruit) with
no apparent ill effects. If you want to be sure, use freezer bags - freezer
bags are made from polypropylene which are said to be impervious to even
water vapor.
Speaking of ethylene, was wondering just how sensitive scionwood is to
ethylene. I have several scions stored in the refrigerator, but since we
try to eat healthy, we also store fresh fruits and vegetables in the fridge.
I try to keep the produce in the bottom and the scions in the top. Can
ethylene enter the plastic bags the scionwood is stored in? Can I tell if
the scionwood is being harmed by ethylene or will they just quietly die?