>He has sprayed the plants with a number of systemic fungicides in
>order to try and stop the rhizomes from rotting but hasn't seen
This is just a shot in the dark, but try lifting the rhizomes, washing them
off (loose the fungicides, quickly), cutting off the necrotic parts and
wrapping them in live sphagnum moss. Put them in a fridge at just above
freezing.
Wait six to seven months and repot the survivors.
Best of luck to your friend.
Rand Nicholson (writserv@mi.net)