chris French wrote:
I have used string for melons in the greenhouse, but the tomatoes I tend to
stick with canes. Is there any reason for using string over canes other
than it's a bit cheaper?
Commercially I've seen them lower the plants on the strings, lying down
the lower part of the plant as they grow to get a bigger harvest (I
think Sacha mentioned this)

Interesting. Does the lower part of the plant form roots on the ground? I
know Nick was talking about slicing open grow-bags and lying the tomatoes
along them to give them more rooting space, then letting them grow upwards
from the end of the growbag.

Although I'm not sure with your* method how you could lie down the bottom
of the plant and then have it going up the string without damaging the stem
at the 'fold'. (* yes, I know it wasn't /your/ method as such)

Maybe also a bit quicker as you don't need to tie them in, you just need
to twist the string round.

True. But that's one of the jobs I actually enjoy. :-)