What tomato leaf disease is this?

[edweather]

Carolyn has a perfect picture of this on page 24 (give or take) of her book but it's not identified. This just started at the bottom of one of my heirlooms. Assuming it's fungal of some kind. Thanks

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[worth1]

I can't say what it is but a good amputation is in order.
I would have long before the disease showed up
You simply can't make it go away like an infection in an animal.

[MissS]

It looks like Early Blight to me.

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Copper alternating with Daconil will help. Also remove and destroy infected foliage. It does not belong in your compost bin.

[bower]

Look for concentric rings on the brown part for confirmed diagnosis of Alternaria blight.

The old advice was that EB overwinters on plant material that isn't fully decomposed, but now they're saying that in many places it can survive in soil for one or two seasons. Also, a hot composting will kill it, but home composting piles often don't because they're not hot enough. If you do compost your plants, don't use that pile on your tomatoes. And a one to two year rotation out of tomatoes/potatoes/peppers might prevent soil borne infections.

It's always been my impression that Early Blight is just endemic in many places, but there are Alternaria relatives with many alternate hosts that are certainly everywhere. Whether A. solani could be entirely prevented by seed treatments, IDK. Probably not if you have a history of growing either tomatoes or potatoes in the area.
The upshot, if EB is endemic to the area, it is pointless to send your plant waste to the dump.

[edweather]

I'm attacking with copper and Daconil and removing infected foliage. Hopefully it will help. Every year it's something. Things are great until it gets humid and rainy. Been an awesome tomato year so far. Thanks for the suggestions.

[edweather]

Look for concentric rings on the brown part for confirmed diagnosis of Alternaria blight.

The old advice was that EB overwinters on plant material that isn't fully decomposed, but now they're saying that in many places it can survive in soil for one or two seasons. Also, a hot composting will kill it, but home composting piles often don't because they're not hot enough. If you do compost your plants, don't use that pile on your tomatoes. And a one to two year rotation out of tomatoes/potatoes/peppers might prevent soil borne infections.

It's always been my impression that Early Blight is just endemic in many places, but there are Alternaria relatives with many alternate hosts that are certainly everywhere. Whether A. solani could be entirely prevented by seed treatments, IDK. Probably not if you have a history of growing either tomatoes or potatoes in the area.
The upshot, if EB is endemic to the area, it is pointless to send your plant waste to the dump.

Thanks, I will be checking for the concentric rings.

[bower]

Another thing about EB on the lower leaves/older leaves - feeding the plants will help.

You know the old saying 'Feed a cold and starve a fever', well it's kind of like that. Every extension office will tell you to feed for Early Blight. Some other things, it might make it worse, but not the EB.