Posted: 22/07/2013 at 09:03
Kevin, can you post a photo of the stems and foliage? If fruit is showing signs of infection, whether fungal, bacterial or viral, it should already be showing on the stems or leaves.
Where did you get the seeds? Bob is right, blight can survive in seeds, but the fermentation stage in the seed-saving process, carried out properly, usually knocks blight on the head. Commercial seeds are either fermented or even treated with acid. Fermentation isn't known to work for viral or bacterial problems in seeds, though.