Yellow leaves with spots... blight? bacteria?

[tankgirl73]

I've got a couple dozen tomato plants doing very nicely. The last few days, I've noticed that a couple plants have a lot of yellowing leaves. These leaves are also covered with small brown speckles and are drying up. They're mostly around the bottom, but there are occasional leaves higher up as well, even to the very top.

It's only a small percentage of the leaves. And it's confined to this one area -- it's 2 or 3 plants right together. That right there leads me to believe it's something "infectious" and not just environmental, because all the plants have the same environmental conditions.

The fruit (lots of growing green tomatoes) all look fine.

I can't figure out what it is, or what I should do about it, or whether I should worry. I've googled pictures and it doesn't look like blight... the spots are too small. It sort of looks like bacterial speck, but not quite. I'm really not sure.

Also, what I've read talks about how the diseases will overwinter in the soil, how important it is to rotate crops, etc. This is a brand new garden, in enclosed raised-bed containers, with brand new soil mix. Where did the disease come from in the first place?

So far, I've been picking off the yellowing branches and discarding them. I assume I shouldn't compost them.

My questions are really, just, how do I figure out what precisely it is, and then what do I do once I know?

[alllyssa]

Some of my tomatoes are doing this too. Seems to only be a tri-colored cherry tomato blend that I started from seed. I have about 5 of these cherry toms in different locations and it seems to be happening to all of them.

It's not affecting my Romas, purple Cherokees, Brandywines, Black Krim, Grapes, etc.

[MacKinnon]

Sounds like Septoria Leaf Spot or Early Blight. Ours started doing that about a month ago. Sadly, despite cutting off the diseased branches and treating with an organic certified fungacide, it has spread rapidly. We've lost two plants Our surviving four, one cherry, one beefsteak, and two roma, look pretty bad. The plus is that our tomatoes ripened faster, as the diseased plants were stressed, and started to ripen their fruit! And the tomatoes are fine to eat. The bad side, obviously, is that we will have a much smaller yield.

Our local Extension office said not to compost anything off the tomatoes, and to be sure to plan the tomatoes in a different place in the garden next year, as the fungus can over winter.