# What is this horrible tomato plant disease? **URL:** \ **Category:** Factual Questions\ **Created:** [May 16, 2006, 5:43pm UTC](https://boards.straightdope.com/t/what-is-this-horrible-tomato-plant-disease/357005 "2006-05-16T17:43:58Z")\ **Posts on this page:** 16\ **Page:** 1
**Author:** ![Zsofia](https://avatars.discourse-cdn.com/v4/letter/z/7bcc69/32.png) [@Zsofia](https://boards.straightdope.com/u/Zsofia)\ **Post date:** [May 16, 2006, 5:43pm UTC](https://boards.straightdope.com/t/what-is-this-horrible-tomato-plant-disease/357005/1 "2006-05-16T17:43:58Z")
Just when my beloved beautiful heirloom tomato plants have started to think about blooming, there’s something wrong with them! It seems to be mostly on the plants to the left of the garden (so maybe it’s something that spreads), and I don’t see any bugs. The blooming ones are to the right. First I noticed some dry, curled leaves, and now I see that they’ve got dead spots all over them. I cut off the affected foliage - no idea if I was supposed to do that, but I panicked! I looked on the Clemson Extension’s information pages and the only thing that seems like it might be it is maybe septoria leaf spot? Except this started on the top foliage, not the bottom, and the pictures I’ve found don’t really look right. Here’s a picture I took, which didn’t come out so great - it’s the third picture. [Horrible no good terribly awful sad leaves](http://www.bulblet.com/archives/2006/im-a-pepper-youre-a-pepper/) I’d really appreciate anything you guys can tell me about it - what it is, what I can do about it. If I have to I’ll take it down to the county extension, but their hours are really inconvenient with my work schedule, so I was hoping the Dope would come through for me. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [May 16, 2006, 6:09pm UTC](https://boards.straightdope.com/t/what-is-this-horrible-tomato-plant-disease/357005/2 "2006-05-16T18:09:56Z")
> [@Zsofia](#): > > [Horrible no good terribly awful sad leaves](http://www.bulblet.com/archives/2006/im-a-pepper-youre-a-pepper/) It looks more like a mineral deficiency than a disease to me. [Color Pictures of Mineral Deficiencies in Tomatoes](http://www.hbci.com/~wenonah/min-def/tomatoes.htm) It’s hard to tell from your photo, but perhaps that purple color makes me think about phosphoros. ---
**Author:** ![Finagle](https://avatars.discourse-cdn.com/v4/letter/f/b19c9b/32.png) [@Finagle](https://boards.straightdope.com/u/Finagle)\ **Post date:** [May 16, 2006, 6:17pm UTC](https://boards.straightdope.com/t/what-is-this-horrible-tomato-plant-disease/357005/3 "2006-05-16T18:17:03Z")
Maybe [tobacco etch?](http://www.ces.ncsu.edu/depts/pp/notes/oldnotes/vg15.htm) Are you a smoker or do you have tobacco fields nearby? Apparently tomatoes are susceptible to many of the viruses that infect tobacco. ---
**Author:** ![Zsofia](https://avatars.discourse-cdn.com/v4/letter/z/7bcc69/32.png) [@Zsofia](https://boards.straightdope.com/u/Zsofia)\ **Post date:** [May 16, 2006, 6:40pm UTC](https://boards.straightdope.com/t/what-is-this-horrible-tomato-plant-disease/357005/4 "2006-05-16T18:40:44Z")
I’m not a smoker, there are no nearby tobacco fields. Could overwatering cause a mineral deficiency? For a while there my drip irrigation timer was malfunctioning and I didn’t realize it, so the plants got a LOT of water as seedlings. Also, we’ve had a lot of rain recently. The soil is “new” and a local mix - everything else is doing amazingly well in it. Should I fertilize? Add something? ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [May 16, 2006, 7:14pm UTC](https://boards.straightdope.com/t/what-is-this-horrible-tomato-plant-disease/357005/5 "2006-05-16T19:14:16Z")
> [@Zsofia](#): > > Could overwatering cause a mineral deficiency? Yes, nitrogen, potassium and phosphorus are all very water soluble, [and subject to leaching](http://www.canr.msu.edu/vanburen/e-896.htm). Tomatoes like _lots_ of nutrients. [Get them some fertilizer.](http://www.google.com/search?hs=q60&hl=en&lr=&c2coff=1&client=firefox-a&rls=org.mozilla%3Aen-US%3Aofficial&q=tomatoes+fertilizer&btnG=Search) ---
**Author:** ![Zsofia](https://avatars.discourse-cdn.com/v4/letter/z/7bcc69/32.png) [@Zsofia](https://boards.straightdope.com/u/Zsofia)\ **Post date:** [May 16, 2006, 7:26pm UTC](https://boards.straightdope.com/t/what-is-this-horrible-tomato-plant-disease/357005/6 "2006-05-16T19:26:40Z")
I’ve got an organic tomato fertilizer at the ready - they got some when I planted them and it directs to side-dress when they set fruit. I should go ahead and side dress? That won’t interfere with flowering or fruit? ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [May 16, 2006, 7:40pm UTC](https://boards.straightdope.com/t/what-is-this-horrible-tomato-plant-disease/357005/7 "2006-05-16T19:40:24Z")
> [@Zsofia](#): > > That won’t interfere with flowering or fruit? Not if you really have leached out everything from the first application. Going too high on nitrogen likely won’t effect fruiting much this early in the season and I think you’ve good evidence of leaching showing up in your plants. But it’s _your_ call. ---
**Author:** ![Zsofia](https://avatars.discourse-cdn.com/v4/letter/z/7bcc69/32.png) [@Zsofia](https://boards.straightdope.com/u/Zsofia)\ **Post date:** [May 16, 2006, 7:53pm UTC](https://boards.straightdope.com/t/what-is-this-horrible-tomato-plant-disease/357005/8 "2006-05-16T19:53:06Z")
So, should I just do it to the plants that are showing those leaves (which do look a lot like that picture)? Or should I do to all of them? ---
**Author:** ![Finagle](https://avatars.discourse-cdn.com/v4/letter/f/b19c9b/32.png) [@Finagle](https://boards.straightdope.com/u/Finagle)\ **Post date:** [May 16, 2006, 8:28pm UTC](https://boards.straightdope.com/t/what-is-this-horrible-tomato-plant-disease/357005/9 "2006-05-16T20:28:45Z")
> [@Zsofia](#): > > So, should I just do it to the plants that are showing those leaves (which do look a lot like that picture)? Or should I do to all of them? Do it to half of the plants, including half of the ones with problems. Then you have a control and you know if your hypothesis is correct. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [May 16, 2006, 9:23pm UTC](https://boards.straightdope.com/t/what-is-this-horrible-tomato-plant-disease/357005/10 "2006-05-16T21:23:05Z")
> [@Finagle](#): > > Do it to half of the plants. This just guarantees half the plants’ll continue to suffer. The objective here is _tomatoes_, not _science_. If the nutrients are leaching, they are going somewhere, perhaps over to the peppers or eggplants you have next to the tomatoes. You don’t want to overfertilize those. I’d just fertilize the obviously affected area. I’ve got a downspout that drains into one corner of my garden, and every year I end up having to fertilize the tomato plant in that corner several times. ---
**Author:** ![Zsofia](https://avatars.discourse-cdn.com/v4/letter/z/7bcc69/32.png) [@Zsofia](https://boards.straightdope.com/u/Zsofia)\ **Post date:** [May 16, 2006, 9:25pm UTC](https://boards.straightdope.com/t/what-is-this-horrible-tomato-plant-disease/357005/11 "2006-05-16T21:25:24Z")
Okay, will do. Any idea on how long it should be until I see some results? (Particularly considering I did, in fear and anger, chop off some planty bits?) ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [May 16, 2006, 9:33pm UTC](https://boards.straightdope.com/t/what-is-this-horrible-tomato-plant-disease/357005/12 "2006-05-16T21:33:39Z")
A week or two should allow significant improvement. (Of course, I’m totally wrong here, and your plants really _are_ suffering from _Southern tobacco rusty wilt mosaic stunt potyvirus_…) ::crosses fingers, hopes for best:: ---
**Author:** ![RetroVertigo](https://avatars.discourse-cdn.com/v4/letter/r/b38774/32.png) [@RetroVertigo](https://boards.straightdope.com/u/RetroVertigo)\ **Post date:** [May 16, 2006, 9:37pm UTC](https://boards.straightdope.com/t/what-is-this-horrible-tomato-plant-disease/357005/13 "2006-05-16T21:37:46Z")
> [@Squink](#): > > that purple color makes me think about phosphoros I’ll second the phosphoros deficiency idea, flowering plants suck down phosphoros. I’ve noticed that alot of the time deficiency in macro-nutes are caused by having a deficiency in micro-nutes (zinc, magnesium, calcium, boron) since nutrient uptake is usally tied together. ---
**Author:** ![RetroVertigo](https://avatars.discourse-cdn.com/v4/letter/r/b38774/32.png) [@RetroVertigo](https://boards.straightdope.com/u/RetroVertigo)\ **Post date:** [May 16, 2006, 9:44pm UTC](https://boards.straightdope.com/t/what-is-this-horrible-tomato-plant-disease/357005/14 "2006-05-16T21:44:14Z")
::stupid submit button:: Have you checked your soils ph? Phosphoros will only be absorbed within a certain range. If this is the case some agricultural limestone could be the solution. ---
**Author:** ![siberia](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/siberia/32/9129_2.png) [@siberia](https://boards.straightdope.com/u/siberia)\ **Post date:** [May 16, 2006, 10:25pm UTC](https://boards.straightdope.com/t/what-is-this-horrible-tomato-plant-disease/357005/15 "2006-05-16T22:25:15Z")
It sure looks like Alternaria canker to me which is a fungal problem. It is spread by wind. Wounding (pruning, etc.) of young plants provide excellent entry points for infection. I will say that without a closeup shot of the damage, I cannot be 100% certain. ---
**Author:** ![Zsofia](https://avatars.discourse-cdn.com/v4/letter/z/7bcc69/32.png) [@Zsofia](https://boards.straightdope.com/u/Zsofia)\ **Post date:** [May 16, 2006, 11:16pm UTC](https://boards.straightdope.com/t/what-is-this-horrible-tomato-plant-disease/357005/16 "2006-05-16T23:16:40Z")
> [@siberia](#): > > It sure looks like Alternaria canker to me which is a fungal problem. It is spread by wind. Wounding (pruning, etc.) of young plants provide excellent entry points for infection. I will say that without a closeup shot of the damage, I cannot be 100% certain. I found some pictures of that one - the leaves could be my problem, but I don’t have those stem cankers. There is a little bit of stem discoloration on the little itty bitty stems with the leaves on them, but that’s just purple splotching, not like the pictures I saw.