Vine Rooting
 

I have a grape vince that has a couple of canes that had laid on the
ground and taken root before I got them up on a trellis. I didn't
uproot them. It's been a couple of years now.

Should I let them remain connected to the original root stock or sever
the connection? The grape yield has been fine enough to please me the
way it is, but I wonder what you all think about leaving it or cutting
it off.