On a radio gardening program they were talking about a method for
propagating your favourite tomato: pick off a couple of the sturdy
horizontal leaders, dip into rooting hormone, and plant into a good
propagating mix. The cuttings take root and each grows into a new
seedling! The host of the program said she tried it, and every one of
the cuttings grew, so concluded that it is not difficult.

This sounds like something you could do early in the growing season,
to turn your best plant into half a dozen slightly behind the first.

In the way of things, I'm prepared to believe this is probably a
re-discovery of an old method for propagating tomatoes. Success might
not be assured with the modern grafted tomatoes: if you plant a cutting
from above the graft it might not do as well in your conditions when
growing on its own root system. It's something you'll need to find out
for yourself.
--
John Savage (my news address is not valid for email)