Thank you for your response, Its outdoor on my deck...how can I treat it ?

Hi, I had the same problem and yes it will spread to the whole plant and all your tomatoes. It's a Fungus, and it will kill you plants very fast. Thanks to Sharon Love Joy's book Trowel & Error, I found a recipe for diluted milk that saved my plants. I used a 3:1 solution(3 parts water, 1 part milk). First I trimmed off all the affected leaves/branches ( this will make your tomatoes look like scarecrows, but it's the only way)-Dont compost the diseased foliage. Then spray with diluted milk for several days. I do it in the shade but early enough that the plants have time to dry before evening coolness sets in. My plants are saved! I cant believe it worked! BTW I live in coastal (June Gloom) CA, in case you were wondering about the plants locale. Hope it works for you, Ziggy

Thanks for the follow-up, everyone. Actually, the leaves that appear to be eaten belong to an ill-conceived dwarf sunflower (which despite being eaten and the shade from the toms nonetheless managed to bloom). There's relatively little tomato leaf eating going on, although I did just catch my first hornworm caterpillar - the kids are keeping it in a jar and feeding it random tomato leaves for now (I suspect it will meet an untimely death if it actually manages to get to the moth stage...). I've looked at the various leaf curl threads - I agree it's likely that. I use straight-up Mel's Mix (1/3 mixed compost) with some 14-14-14 CRF thrown in at mixing time for good measure. I've given the plants probably three MG feedings but have come to the conclusion that I need to move away from high-nitrogen ferts for tomoatoes. I've just gotten an organic fish/kelp fertilizer and will use that instead (it's 2-5-1) and will probably alternate that with MG Tomato (18-18-21). Other than the micro-nutes from MG I haven't added anything else. Interesting observation about Mel's Mix draining too fast but somewhat hard to act on. I've been pruning down to one vine, so that could be a stress factor as well. I've also sprayed with Serenade thinking I had something more serious. Thanks again for the feedback - any other insights would be very welcome.

Where did you get your tree from? Home Depot? I wonder is the issue is the roots i.e. Rootbound.