Help...what have I got, how do I fix it?
 

Here is a picture of leaves I removed from a tomato plant in my garden. Any ideas what it is and how do I get rid of it?

Looks a lot like Septoria. Take off any leaves that have the brown spots. They'll most likely be at the bottom. Bag them up; don't let them lay around the garden and don't compost them. Next, get Bonide copper fungicide spray, or the equivalent. Spray all your tomato plants although try not to hit the blossoms too hard. Get the underside of leaves as much as possible. Try to do this when you have a few days without rain, so it won't wash off. Best to do the spraying near the end of the day, or very early so it'll dry before the sun is too hot. I have septoria here; I've found Post Office Spoonful is a good tasting small cherry that grows so fast it outgrows septoria and doesn't seem too much affected (blossoms don't abort, for example). Dotson's Lebanese Heart is another that keeps on producing through Septoria.
Nan

Yup, Miss Nan is spot-on, methinks. I get it every year to some degree...it's manageable.

It's hard to actually "get rid of it" but you can manage to keep it under control so you get a harvest and keep it progressing slowly. If you find you're spraying every week, you might want to switch off with a product called Daconil. I don't recommend putting a lot of copper into your soil. The problem with Daconil is getting it to spray on the plant; mostly it comes out in a stream that's horrible to try to get all over a plant. If you have a pump sprayer, I guess it's easier.
Nan

[QUOTE=Nan_PA_6b;706030]Looks a lot like Septoria. Take off any leaves that have the brown spots. They'll most likely be at the bottom. Bag them up; don't let them lay around the garden and don't compost them. Next, get Bonide copper fungicide spray, or the equivalent. Spray all your tomato plants although try not to hit the blossoms too hard. Get the underside of leaves as much as possible. Try to do this when you have a few days without rain, so it won't wash off. Best to do the spraying near the end of the day, or very early so it'll dry before the sun is too hot. I have septoria here; I've found Post Office Spoonful is a good tasting small cherry that grows so fast it outgrows septoria and doesn't seem too much affected (blossoms don't abort, for example). Dotson's Lebanese Heart is another that keeps on producing through Septoria.
Nan[/QUOTE]

This. I use Southern Ag brand liquid copper fungicide. Any is OK.