Early blight

I think my tomatoes are in trouble. They are all flowering away beautifully but lower down there is a problem. I've searched the net and am not clear on which particular blight I've got but something is wrong and I guess I am going to have to do something. The Brandywine look the dodgiest.



I'm wondering whether I can get away with lopping off the offending leaves and spraying with something. Two options to spray with: copper spray and this mixture I found on an organic gardening site (a mixture of one part milk to four parts water, along with 1 teaspoon of baking soda for every quart of water used. A few drops of liquid soap will help to make the spray stick). What do you think?

It just seems so ruthless to bin the whole plant but if it will save the rest of the crop I suppose I have to grit my teeth and get on with it. The worst of it is that once you start really looking at the plants you see it everywhere.