Geoff -
I used some brassicas that cycled from seed to seed again over the
course of a semester. The prof that put me on to them was Dan Cosgrove
at Penn State. I don't have his email, but I am sure he is in the ASPP
directory and also on the PSU gopher server. He should be able to give
you his source.
Laura Butterfield
CT Ag. Expt. Station
New Haven, CT 06504
laurajwb at connix.com