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Tomato problem identification (w/ pics): Has anyone had Rust b4?

Posted by darcygarden 10 (My Page) on
Tue, May 20, 08 at 17:49

I am trying to identify what is wrong with my tomato plant. I have checked problem solver #2 as well as searched the internet. The only thing I can find that looks close to what is happening to my plant is the rust fungus. The research I've been able to find says that rust can be a problem along the pacific (where I live), but I can only find information on the rust fungus effecting beans. Has anyone out there had rust on a tomato plant?

Any thoughts would be greatly appreciated.
What does this look like: TOMATO SPOT PROBLEM (5 Pics)

I'm sorry to post about this again, but i found a few similar spots on one of my other tomatoes. If this is rust, then I think there is some stuff I could do now to save the plants. My other theory is that it could be Alternaria Canker because of the black powder appearing on the stems (sort of visible in one of the pics).

I will take a section into the LA extension office if I can't get it under control- but the guy at OSH just told me the wait for results could be over a month, so I'm hoping to "trial and error it" with the new spots I've found on my other tomatoes.

Here is some info I posted earlier about this plant:
-About 1.5 weeks ago I noticed the new growth was purple tinted with dark purple veins. I thought it was potassium so I used seaweed.

-a few days later I noticed what appeared to be black powder on the undersides of some of the older leaves- when I touched the stuff it was sticky. The man at the nursery said it was probably sooty black mold from the neighboring magnolia tree and it should wash off, but it didn't wash off. I tried Safer fungicide.

-today I found that the 'sooty black mold' (?) has spread all over the plant. Not only can I not wash it off, I CAN'T SCRAPE THE STUFF OFF!! The powdery looking black spots have burned into the leaves and it is on the tops of some as well as the stem.

There is no yellowing on the leaves and the black spots are TINY- seriously- the size of sand. The plant is producing tomatoes and has many flowers, though I noticed a very faint "lighter" blotch on the largest tomato (still green). Also, I would have to say the growth of the entire plant has slowed in the last few weeks.

Any thoughts would be greatly appreciated.
Thanks in advance.

Follow-Up Postings:

RE: Tomato problem identification (w/ pics): Has anyone had Rust

Has anyone out there had rust on a tomato plant? I never have nor have I ever heard of it being a problem but since these plants are apparently indoors and house with other carriers I suppose it is possible.

But I would think using the fungicide should have at least improved the condition IF it is a fungus. I don't know off hand the concentration of the chemical in the Safer product - I know that the stronger concentrations of at lest 25-29% are the ones usually recommended.

But I do have a suggestion to try. It is possible that this is bacterial rather than fungul - just a guess from the pics but perhaps bacterial spot. If it is then a fungicide won't help but a peroxide spray might. It can't hurt and might help. Mix up a 9:1 dilution of water and hydogen peroxide (9 parts water to 1 part HP) and mist it on the infected areas. They won't disappear - the damage is done to the leaf tissue - but they shouldn't spread either IF it is bacterial.

When can these plants go outside where the sun and wind/air circulation may control some of this problem?


RE: Tomato problem identification (w/ pics): Has anyone had Rust

  • Posted by jean001 z8aPortland, OR (My Page) on
    Tue, May 20, 08 at 19:43

Don't know what it is. But it's not rust.

RE: Tomato problem identification (w/ pics): Has anyone had Rust

Darcy, It looks like leaf spot which is a fungus disease. The fungus that causes the disease lives in the soil. Have you grown tomatoes in the same spot before? Check out the link.

Here is a link that might be useful: Septoria Leaf Spot of Tomato

RE: Tomato problem identification (w/ pics): Has anyone had Rust

I agree with the PP...septoria fungus. I have the same thing on one of my very new seedlings. Supposedly it doesn't develop until time of fruit set...and I'm about 4 weeks early for that...but it best fits what I'm seeing on my tomato leaves.

RE: Tomato problem identification (w/ pics): Has anyone had Rust

Thanks so much for the info. Sorry it took me a few days to reply, my work schedule has been a little insane...

I had thought leaf spot was possible, but the beginning stage of this fungus was like nothing I could find (picture or description) describing Septoria. It looked like a black/brown dust (raised) was covering the undersides of the leaves- like someone held the plant upside-down and spilled soil on it :) If two of you think that's what it is, then it must be. I thought rust both because that was the ONLY fungus that looked even remotely similar and we had rust on a jasmine vine planted about 6 feet away in the flower bed (this tomato is potted so it does not share soil with any plants).

The good news is- after an all out assault of (Safer) fungicide (every 4 days) and seaweed- the plant appears to be in recovery. A couple of the young tomatoes appear to be a bit deformed so I'm going to keep a close eye on it. The leaf loss was quite extensive, so I may have a problem with sun scald. (btw, in a couple of the photos you can see the whole plant behind me- it's the potted plant on the white stand).

QUESTIONs: If I start using Fish Emulsion with the seaweed now will it encourage some more leaf production to help the sun scald problem? Or will any new leaf growth be effected by the fungus?

The plant is potted so I have not grown anything in the soil before, it must have picked up the disease at the nursery. This is my ONLY potted tomato and I'm noticing a few spots on my other tomatoes (planted in a garden), if I catch this fungus early enough will it contaminate the soil?

Sorry if it was unclear, all of my plants are outside (I brought my laptop out and used the camera built into it to take the pics- GO MAC!!!)

Thanks again for all the posts, diagnosing this little fungus had truly been driving me crazy!

RE: Tomato problem identification (w/ pics): Has anyone had Rust

..."- like someone held the plant upside-down and spilled soil on it "...

Funny you should say that. That is the *exact* thing I thought when I first saw my plants looking like that. Then I realized it didn't brush or wash off.

Glad you found a treatment that seems to be working for you.

My guess is that there's a distinct possibility that even when caught early, the soil will harbor the fungus easily and it will reproduce and spread. Probably only takes a few spores and a bit of moisture.

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