Seedling stem damage at the soil

[DeXodus]

Dear gardeners,

I need some help to identify a problem of a few seedlings that I have.
I am growing some black locust (robinia pseudoacacia) seedlings from seed. Currently they are about 3-4 weeks old. They are planted in a coconut choir that is enriched with fertilizer and vermiculite mixture (50:50). I water them daily very small amounts. I had 3 of them and then one of them fell over. After inspecting I found that the stem at the soil level was damaged. It looked as if it was chewed off. Here is the image of what I recovered:
http://s31.postimg.org/neuus4v23/13090882_1272310596131978_777277671_o.jpg
After inspecting the other two I found similar but smaller wounds on the stems. Here is the seeding with bigger wound:
http://s20.postimg.org/eq3a5xhm5/13063974_1272310602798644_1295072663_o.jpg
http://s20.postimg.org/mwv9xi7ot/13054631_1272310592798645_1038304812_o.jpg
What could have caused this?

 

[ChrisL]

I had a similar problem just last week. Looks identical damage-wise, although I planted beans. Thanks to some good advice from this very site, I identified cutworm. Even dug some up once I knew what to look for.

 

[DeXodus]

This is weird because I am growing these plants inside my apartment, in (atleast I think it is) sterile substrate. Is it still possible to get cutworms in this way?

 

[Chuck]

I don't think that is cutworm damage. I have never seen a cutworm not completely chew through a seedling and aside from that a moth would have had to fly in and lay eggs. That looks, from what I can see, to be damping off disease. I have heard on this forum that damping off is non-existent in Europe so maybe it isn't. Another possible suspect could be roaches. I have seen them chew off a small portion of stem and "drink" the sap that comes out.

 

[DeXodus]

And what is a possible solution for damping off if that is a case? I would doubt roaches because I live in a student dorm which is rather new so I would hope there are non. But you never know.

 

[Chuck]

I don't think that is cutworm damage. I have never seen a cutworm not completely chew through a seedling. That looks, from what I can see, to be

And what is a possible solution for damping off if that is a case? I would doubt roaches because I live in a student dorm which is rather new so I would hope there are non. But you never know.

Your post made me curious so I did a little research. Googled black locust damping off and sure enough the tree is quite susceptible to damping off disease. Unfortunately once damping off occurs to your plant it will be fatal, but the good news is, is that your can prevent it from happening again. All you have to do is mix horticultural cornmeal into your planting medium and when the seed sprouts sprinkle moderately around and on the plant. You can also, to be doubly sure, make a cornmeal tea and spray the plant.

I doubt it is roaches either. The only time I ever saw it was on okra.

 

[DeXodus]

Should I get rid of the current substrate? As I understand damping off happens because of a fungi. Yet I read that as spores travel easy this may not help.

 

[Chuck]

Should I get rid of the current substrate? As I understand damping off happens because of a fungi. Yet I read that as spores travel easy this may not help.

Yes, damping off is a soil born fungus. I would start new seeds in something else but also do this. Check around and see if damping off disease is even possible where your live.

 

[DeXodus]

Could it be by any chance heat lesions? Because I was now just reading that damping off lesions are dark in color and heat lesions are positioned at one side and is whitish. I have a growlamp to supplement natural light but it is only 11W fluorescent lamp, yet my substrate is rather dark so it can soak up alot of heat I guess.

 

[Chuck]

Could it be by any chance heat lesions? Because I was now just reading that damping off lesions are dark in color and heat lesions are positioned at one side and is whitish. I have a growlamp to supplement natural light but it is only 11W fluorescent lamp, yet my substrate is rather dark so it can soak up alot of heat I guess.

I hope it is heat lesions but I think it extremely unlikely because the temperature requirement is high, between 120F-130F. That is hot and I just can't see a 11 watt bulb creating that kind of heat dark soil or not.
I grow many seedlings each year and I have encountered damping off on many different plants and IMO there is no "one size fits all" as to the physical descriptions of the plants injuries. Even among the same variety plant, damping off will take different forms. Take tomatoes for instance. Side by side in the same container one plant will take on a square shape at soil level before turning white and falling over and the one next to it will just turn brown at soil level, shrivel and fall over dead. You may not have damping off, but it won't hurt to prevent it whether you have it or not. Horticultural or Whole Ground or Stone Ground cornmeal is cheap so why take a chance? The cornmeal you get at the grocery store is normally the "enriched" kind. If the package says ENRICHED anywhere on it, IT IS NOT THE RIGHT KIND and WILL NOT WORK.

 

[DeXodus]

I will try the cornmeal then and look if the new ones will have any damage when grown.

 

[Chuck]

I will try the cornmeal then and look if the new ones will have any damage when grown.

And I would be interested to know if there really is damping off in Europe or not.

 

[DeXodus]

So this may be a bit late, but I wanted to make sure. So this plant that I talked before died. I removed the growing media and found completely withered and undeveloped root system. I started new seedlings right after that and now I grown them to the level they where before. I watered them only by soaking the pot though bottom and watered only when media would dry up. No repeating incident up to now. Everything SEEMS to be pointing out to damping off. So it may be that it actually exists in Europe. Just wanted you to know.

 

[Chuck]

So this may be a bit late, but I wanted to make sure. So this plant that I talked before died. I removed the growing media and found completely withered and undeveloped root system. I started new seedlings right after that and now I grown them to the level they where before. I watered them only by soaking the pot though bottom and watered only when media would dry up. No repeating incident up to now. Everything SEEMS to be pointing out to damping off. So it may be that it actually exists in Europe. Just wanted you to know.

did you use the cornmeal too?

 

[DeXodus]

Sadly no. I moved to new country for job/study reasons, and I don't know the language so it was bit too time consuming to try to find some. And in Europe corn products are not popular.