Hey, new here but desperately needing a positive ID on the problem cropping up in my tomato seedlings. I've never grown them from seed before so I don't know what to look for. No disease profiles online seem to match it exactly - I thought maybe bacterial spot/canker, but it's not quite right and it's so dry here that it didn't make much sense anyway. Maybe nutrient deficiency? Some sort of fungus? I just need to figure out if it's safe to put these in the garden come last frost time, without contaminating the soil with something nasty.
So: They're about 5 weeks old, mixed varieties (supersweet 100 cherry, roma, early girl, big boy, brandywine, and a mix of other heirlooms from burpee). The problem in the pictures is primarily on the older leaves, but younger leaves eventually get it too. Nothing wrong on the stems, plants seem strong and lively. Seed leaves have been yellowing and falling off on their own. Currently fertilizing with Age Old Grow (20-10-10), which is organic and not supposed to be able to burn plants, but for a while they were just in seed starter with no added nutrients. Drainage is good, and they're under a sun lamp so they should be getting enough light? Though it's only 100w, so who knows.
Anyway, pics:
[img]https://I.imgur.com/DBJPd.jpg[/img]
[img]https://I.imgur.com/5ZjCl.jpg[/img]
Any ideas?
In the very beginning, I was just watering from above, but in probably the last three weeks I've held the leaves aside and watered at soil level. So the leaves shouldn't have been wet for a long while. Very good point though, and something I'l have to be careful of, esp as I start moving them out into the real sun.