Oh, meant to add. We spray copper on the tomatoes prophylactically when we set them out. Dose them really really good. And the ground under them and them mulch as well. Especially after losing every tomato plant last year. It’s fairly cheap, ‘organic’, and doesn’t burn if done correctly. We considered it insurance this year.
If you already have blighty/yellowish leaves you might want to look online for pictures of blighty leaves. If it looks like you might have it you’ll need to pull off the infected leaves. Carefully so as not to touch the rest of the good green leaves. I use gloves and dip those in bleach when done so I don’t spread the spores. Remove the infected leaves from the garden altogether. I put them in my garbage can with a good spritzing of bleach from my household sprayer. I have a plant that looks that way that I’m going to have to deal with tomorrow. Can’t be too careful.
Early blight, from what I’ve read, is in the soil in places. So mulching with papers and straw or something helps. It’s spread by raindrops/splatters. So if you can keep the soil ‘under’ something so it doesn’t splatter on the bottom tomato leaves when it rains that helps control its spread.
Thanks for the info :o}