Here's the purple-y brandywine's leaf

I do believe the 1st pic is Early Blight.
On the 2nd pic, what size container and type of soil mix are you using. Brandywine and Sungold are a very large plant and needs considerable "root space". Root bound plants will struggle to take up water and nutrients.

This post was edited by geosankie on Sun, Dec 29, 13 at 13:36

First picture indicates fungal. Either Early Blight or Septoria Leaf Spot. I can't see the definition of the spots with the picture well enough in order to differentiate, but the problem is treated the same/

Second Picture? Possible Tomato Spotted Wilt Virus, see the link below.

And notice the several pictures with a purple tint as well as a blistered kind of foliage as you show for your Brandywine. Normally the leaves of Brandywine are smooth .

Carolyn

Here is a link that might be useful: TSWV

This post was edited by carolyn137 on Sun, Dec 29, 13 at 12:54

Geosankie, both plants are in 5 gallon containers. It's the brandywine that is purple, not the sun gold. Sun gold is doing great other than the early blight :/

Sun gold is in Lamberts organic potting soil and brandywine is in MiracleGro regular potting soil.

Carolyn137, I am not convinced yet that the brandywine has spotted wilt virus as the purple parts of the leaves are not dying. I'm not sure what to do though. And how should I treat the early blight?

There are lots of dying leaves shown in the link I gave above.

TSWV is caused by thrips of a certain kind and if you did a Google search I'm sure you'd come up with more such pictures.

It's a suggestion, not a definitive diagnosis, since you say that your other plants don't have the same symptoms.

Since all of your plants were given the same growing conditions the purple can't be due to a mineral deficiency, and leaves can turn purple in cold weather as well, but it's not cold where you are right now.

Carolyn