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Tomato leaves covered in powder sized black spots- purple veins-

Posted by darcygarden 10 SoCA (My Page) on
Fri, May 16, 08 at 1:16

I am going CRAZY trying to find out what is wrong with my tomato plant. This is my only potted tomato and I have no idea what kind it is (it had no tags when I bought it).

The plant is on a stand and sits at eye level so I've been able to keep a good watch over it. I have noticed no aphids, no thrips, and only one hornworm in the 2 months it has been planted. It is our most vigorous plant in terms of foliage growth (3ft x 3ft bush). The plant still looks pretty healthy, BUT...

-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.

I have spent hours looking up every tomato virus, fungus, and mold known to SoCA and nothing seems to match up.
Does anyone know what this is? I don't want to throw it out, it still looks healthy- but I don't want anything spreading to the rest of my tomatoes.

I'm sorry, my camera has broken- I will try to borrow my neighbors this weekend to get a pic.

Follow-Up Postings:

RE: Tomato leaves covered in powder sized black spots- purple vei

Over on the Tomato Pest & Diseases forum you'll find a long post called Problem Solver 2. Just use the forum search for that form if it isn't still on the front page. It is filled with links to images of the different tomato diseases. Browse them and see if you can find a pic that matches your problems.

Off hand it sounds like you have a fungus problem (the black spots) from your description but I can't be sure without seeing it or a great many more details. If that is the case then spraying with an anti-fungus spray such as Daconil (sold under several different names) will help control it.

The purpleing leaves and veins are due to stress - normal for a stressed plants - and will disappear once you ID the other problem and treat it.

Good luck.


Here is a link that might be useful: Tomato Pests & Diseases forum

RE: Tomato leaves covered in powder sized black spots- purple vei

Thanks Dave, but I forgot to mention that I already checked Problem Solver 2.
Here are some pictures (sorry, I had to take them on my laptop so the quality isn't great)

Tomato spot problem

pictures above

The leaves have started curling upwards- visible in the pics. I am diagnosing this plant with about 5 different diseases in my head :)
If I can't figure out what this is by next week, I think I'm going to pitch it... for my own mental health.

RE: Tomato leaves covered in powder sized black spots- purple vei

Could this be spider mites? It looks similar to the black sludge they sometimes leave on plants.

RE: Tomato leaves covered in powder sized black spots- purple vei

Don't pitch it. If you do you'll never know what problem you have and might have the same thing again in the future. Instead, take a sample of the plant to your local cooperative extension office and let them tell you what's wrong and what to do. Pictures can sometimes give a lead to a good diagnosis but hands on with a microscope is far better. Good luck. Don't obsess too much.

RE: Tomato leaves covered in powder sized black spots- purple vei

I have noticed the same thing on my determinate plants growing in containers. Same black marks, leaf curl and purple veining. I have not been successful in determining what it is. The tomatoes that set the earliest are big and just starting to blush. The newer tomatoes seem to be stunted and stopped growing. (I know determinates set all it's fruit at once and then decline, but the later tomatoes are abnormally smaller than they should be). So I was wondering what became of your plants and if you found a diagnosis? I am also growing other varieties of indeterminates that are not showing this at all, although I should mention that they are in a different party of my yard and planted in the ground. I'm beginning to think it may be a mineral deficiency~ it makes sense that they would require more fertilizer?

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