Hi there
Jaki - grow bags, two reasons for not using them. 1, they would require more watering rather than just leaving them to get on with it. With the best will in the world, I can't always get up to the allotment and it might be a week between visits which I don't think they would like. 2, plastic. I'm keen to do this as 'naturally' as possible, so even if it was on the cards in time etc, I think I would still not opt to do it.
Meta - (hope you don't mind me using your first name
) We used blight resistant tomatoes last year, and they were resistant, but not immune. They lasted so much longer than the self seeded ones that appeared randomly over the allotment, but still succumbed, just as the fruit was considering ripening. We planted them late, so will try earlier this year and fingers crossed. You are right about the climatic aspect of it, and both years it was when we had a wet spell that it finished off any last resistance and hope.
I still wonder though how long the spores would persist in the soil as when a plot (in fact all my neighbours are the same) has blight potential, every small advantage that can be squeezed out of it to give me an edge is needed. Knowing that (for example) 4 years sees an affected area clear of spores would give me some confidence going forward. As it is, the solanacea family of foods are dropping down my planting lists, as I don't want to spend time and effort on something that is just going to wither away before I get to it.
Cheers
Sven