Agree that based on the info given, over-watering is far more likely to be the culprit. But I'd also evaluate the possible need for nutrient supplement (N) before I'd jump on the disease bandwagon.

A photo might help.

Dave

If your beds are as well drained as you say, I'll go the other direction, and say it might be some disease. Are the plants growing very thick? Might help to remove some of the bad foliage and some interior branches to air them out a bit. A fungicide never hurt either. Maybe post a photo. We've had 3 FEET of rain here in the past 3 months, and my well draining containers show no signs of over watering. Fighting a little disease now and then has been an issue here in hot humid Georgia.

Will post pict later, i removed the affected foliage before posting to avoid diseases. So far there was none on tomatoes.

Yellowing showed up on my 2 plants. One is in a wet spot. But Brandywine is not. My neigbor has one plant with the same yellowing too.

The plants spaced 4 ft apart in Texas Tomato cages - 24"

The last side dressing was done at the end of july - coop poo (pelletized chicken manure)

I already added rootshield to the soil of these plants now and going to add 1 tbs of DoubleNickel.

we are having a heat wave for 3 days, maybe the soil dries up a bit.

i always have a hard time to recognize fusarium vs overraining

Here the pict but folliage was removed earlier, just a couple left

Those plants look pretty good. I see you are in NJ, so endless wet hot humid weather isn't your enemy, but it is still summer, and you can still have a few problems. Knowing what I do now, I'd still thin a few of the interior branches to open them up and air them out a bit. The foliage is pretty dense, and there is little upside to having it so thick imo. Anyway, keep removing the yellow stuff. Looks like lots of nice tomatoes in there.

They start like that, then become bright yellow and i cut them at that point

I am trying not to thin much, Brandywine is a pretty open plant and if disease hits, i would have to remove plenty of leaves anyway.

we have a tropical weather this summer, rains a lot, humid and hot

but at least nights were cool, even below 70's

so not much diseases so far

Ok, sounds good. If you aren't using a fungicide as a regular part of your maintenance, suggest that you think about it.