In article ,
(Sacha) wrote:

He says that he knows of no truly effective inorganic control,
either. In his opinion, the only answer is to pull them out and burn
them. Don't plant new plants in the same area.

So much varying advice! EG:

HDRA says in http://www.hdra.org.uk/factsheets/dc17.htm

"It is probably wise not to compost tomato fruits either. Infected
potato and tomato haulms (foliage) may be composted in a good active
heap. The likelihood of resistant spores being present is very slim.
Infection is much more likely to come from external sources"

RHA says in http://www.rhs.org.uk/advice/profile...ato_blight.asp

"The fungus can be seed-borne, so do not save seed from infected fruit.
Destroy infected plants - do not compost them"

Steve Harris - Cheltenham - Real address steve AT netservs DOT com