[Casey76]

Several of my tomato plants have been struck by blight

Do I have to destroy the whole plant, ot just the sections/leaves/fruits which have been effected?

Thanks

[mumofstig]

You can try taking off all the affected bits, and wait and see, can't do any harm........

unless you have potatoes as well 

[JayG]

I have in the past managed to save a tomato plant showing signs of blight on the leaves, but the plants were grown apart from any other tomatoes and the spuds were already dug and eaten!

If you can't easily remove all the blighted material I think it's safer to destroy them, not forgetting to wash your hands before you touch any of the others.

Make sure you don't make things even easier for the disease by having overcrowded stems and leaves which can trap water and create a perfect microclimate for spore germination.