Sorry but what you describe sure doesn't sound like Late Blight. Plants don't "hang on" with Late Blight.

LB (p. infestans) turns the plant black and takes the plant down completely within just a few days to a week. The plants need to be carefully destroyed ASAP when it is diagnosed to prevent the windblown spread of the fungus to other gardens much less other plants.

Are you absolutely sure that is what you have? And if so have you reported it to your county ag extension. Are there reports of it currently in your county? Late Blight is carefully tracked and mapped all across the country since it is so severe and can wipe out the crops in a whole county or even a whole region as it did 2 years ago.

But no Brandywine is not resistant to Late Blight (or much of anything else). No variety with the exception of a couple of relative new hybrid varieties have some genetic resistance to it.

Dave

Here is a link that might be useful: Late Blight pics

Dave I really don't know what it is for sure maybe you can tell me but anyway the brandywine don't seem to be affected by it. and I just wondered if there was something special about it.

xxx1angel3xxx, could we have a close-up photo of some of the leaves which are just starting to have problems?

Are there black or dark spots on the main stem(s)?

Where in zone 8 are you located?

I'll get a pic tomorrow. I really would like to know what takes them out. with most it's very fast and they die very quick, but the better boy seems to be hanging in there as it still has some good branches. the brandywine however has not shown any sign of it, and that blows my mind because I've always heard like Dave said that if it's out there they will get it... in any event I will save the seed from it if I can.. I mean I broke one part of it and it still didn't stop going. it's not a very big vine,and I let it get root bound in the starter pot. if I get seed from it I will put it up for trade as far as I see this a really good tomato plant. I would love to see it get around. I will need everyone help to teach me the proper way to save seed