From the photos it looks like early blight. You can treat it organically with copper spray or an organic fungicide. Here's a page that explains more: http://www.tomatodirt.com/tomato-blight-early.html.) With treatment the plant can continue to grow and produce throughout the season, although it may not look pretty.

As for fusarium wilt, the prognosis is less favorable ... to date there is no effective treatment for tomato plants. (See this page devoted to fusarium wilt on tomatoes: http://www.tomatodirt.com/fusarium-wilt.html). Experienced gardeners often recommend destroying the plant. Alternatively you can keep the soil pH in between 6.5 and 7.0 to slow the disease.

Good luck!

Here is a link that might be useful: Early blight in tomatoes: how to identify and treat it

Hello Chris,

Question #1. The key word there is resistant, it doesn't say bullet proof. A resistant plant can still get the disease they were bred to be resist.

As for Question #2. Looking at your photos, I am not sure that you have early blight, as they don't show the "typical" symptoms that the Texas A & M site lists:

"Leaf symptoms of early blight are large irregular patches of black, necrotic tissue surrounded by larger yellow areas. The leaf spots have a characteristic concentric banding appearance (oyster-shell or bullâÂÂs eye)."

Cornell's photos of Early Blight on Tomato Leaves

The spots on the fruit, do they show the symptoms listed here: Cottony Leak? Is the center of those spots watery? (Which can be caused by several fungi, as noted on that page.)

To me, what you have, looks like it might actually be a case of fertilizer burn. Check out number 12 on this page. Also if you do a Google image search for"fertilizer burn on tomatoes" you will see several picture that look a lot like some of yours. Many new gardeners are guilty of "over loving" their tomatoes.

To be able to suggest what might be wrong with your plant, it would be helpful to know more about the environment it is in. So, here are the "usual" questions:

Is the plant in the ground or in a container?

If in a container, what growing medium are you using? How large is the container? Is it self-watering or do you manually water it? Is the container in full sun, part sun or shade?

For both container plants and inground plants, it would be helpful to know these things as well: How often do you water? Have you checked the moisture of the growing medium or soil 3-5" below the surface? Is it dry, just right, or soggy? Are you feeding the plant? How often? What are the NPK values of any fertilizers you are using to feed it? What has the weather been like in your area?

If the plant is in the ground: Have you used any amendments? Do you mulch? If so, with what and how much (how deep)? Are there any other plants near the problem plant that are showing similar issues?

The more information you can give us, the better the chances that someone can give you an accurate diagnosis.

Betsy

This post was edited by bets on Sun, Jun 16, 13 at 19:36

Thanks everyone. To answer some questions, it gets full sun, and is in a 1' tall raised bed, filled with a soil mix from a local nursery. I believe the mix contains compost, wood particles, sand, maybe some fertilizer... it seems pretty fast-draining. I've been watering every 2-3 days, using a hose or watering can at ground level (trying to avoid the foliage) and using the wooden chopstick method recommended here to determine when it's needed. I think I was initially overwatering, and now am erring on the side of letting it dry out too much, but I've never seen the plant start to wilt. I sprinkled a small handful of organic fertilizer (3-6-4) a few weeks ago and watered it in, but that's it. I have 3 other plants in the same bed / growing conditions: an Arkansas Traveler that's starting to show some affected foliage, and a Champion 2 and a Purple Calabash that are both fine. I hadn't mulched, but just added 2" of straw this weekend. The weather has averaged highs in the upper 80s and lows in the upper 50s over the past 2 weeks. I have sprinklers on the yard, and some of the mist might be hitting my tomatoes, but not much.
I haven't seen any stinkbugs in the garden, but I'm not sure what time of day they're active. I've been looking at a lot of pictures online, but haven't seen anything that really matches what I'm seeing. The foliage problems usually start with black, dried out edges, and then progressively turns yellow up the leaf and back along the leaf stem to the main stem, at which point the leaf stem dies and is really easy to break off. The foliage that is sickening doesn't seem to be particularly humid or damp. I don't think it could be over-fertilizing or incorrect watering, but I don't know - that's why I'm asking the experts! :-) The disease seemed to start at the bottom of the plant and spread upward. The plant is continuing to produce good foliage at the growing tips, and is sprouting from the base as well. The spots on the tomatoes seem to just be cosmetic - the fruit is solid underneath, not watery, and it tastes good.
Thanks again for all your help! If you need any more specific pictures to make a diagnosis, please let me know. I'm happy to try using a copper spray or something to see if that helps - could it hurt, or can it harm other garden vegetables (like the chard I have next to that tomato plant?)