Tomato Seedlings Leaf Problems

Question: I have been growing tomatoes from seed for about 5 weeks under grow lights. Overall, the transplants look pretty strong, but one variety in particular has leaf browning/drying at the leaf veins. This problem seems to be contained to the Glacier variety (https://www.botanicalinterests.com/product/Glacier-Bush-Tomato-Seeds), which I have not grown before. The leaves have been very curled from the beginning, but I thought this might just be the way the variety looks. These four plants are much smaller than my other varieties. There are a few concerns with other varieties too, however, mostly early leaves (not just cotyledons) yellowing/wilting/dying, but the newest, biggest leaves appear healthy. (My main concern is the Glaciers right now, as they look the worst, but I thought I should provide this other tidbit in case it helps.) I hope to discern if my tomatoes will outgrow whatever is affecting them or if they will continue to have problems and perhaps I shouldn't bother planting them outside next month.

More context: I reused my plastic seed trays from previous years, but made sure to wash them well and disinfect with bleach. My seed-starting medium was leftover from last year--not reused but the bag had been opened. White mold does tend to grow on the top of the soil in my house (in most all of my houseplants, not just these seedlings) but it doesn't usually hurt the plant. 

Thanks for any insight you can provide to what's going on!

responder: The Question Asker Replied April 24, 2023, 9:49 AM EDT
response: (Forgot to attach the form!)

responder: Susan, UVM Extension Master Gardener Volunteer  Replied April 25, 2023, 11:11 AM EDT
response: Rachel:  Thank you for contacting the UVM Extension Master Gardener Helpline.   The photos you sent are very helpful in order to see the problem with your tomato plants.  First of all, these Glacier plants with the potato shaped leaves are an heirloom variety tomato. Heirloom tomato plants tend to be more finicky with growing conditions and also tend to have more problems.  In looking at the photo, the plant itself looks fine, and I would suggest just removing these lower leaves.  Curling leaves usually happen at the bottom of the plant.   Also, your seed starting mix may be the cause of the problem.  (I have attached information from various universities below, that stress the importance of new, fresh, seed starting mix.) These plants are large enough to transplant, so I would suggest transplanting them into another pot with new sterile potting soil, and I believe the plant should be fine. Other things to keep in mind:  if you are using grow lights, keep the lights within a few inches of the plants as they grow, and raise the light as needed.  This will prevent tall leggy plants.  Also, start tomato seeds indoors approximately 6 weeks before last frost date (late May or Memorial Day timeframe is the time to set plants out in the garden, after giving them a week or two outdoors in a shady area to harden off). Heat mats for starting tomato seeds will ensure that the proper 65 - 85 degree temperatures will aid in seed germination. Don't let soil dry out, but don't leave soil soggy, as this may result in fungal problems, such as damping off. When you set out these heirloom tomatoes, try to not let the lower leaves touch the ground, as soil spores will splash up.  Remove these leaves.  Heirlooms tend to be more susceptible to blight.  But, you can't beat the taste, so they are worth the effort! I hope you find the information below helpful.  I especially like the University of Maine fact sheet! How to prevent seedling damping off | UMN Extension FS787: Starting Vegetable Seeds Indoors (Rutgers NJAES) Tips for growing tricky heirloom tomatoes | Illinois Extension | UIUC Bulletin #2751, Starting Seeds at Home - Cooperative Extension Publications - University of Maine Cooperative Extension (umaine.edu)

responder: The Question Asker Replied April 25, 2023, 7:43 PM EDT
response: Hi Susan! Thank you for your response. I do have the seedlings under lights, and in fact I already transplanted them once. I guess I started them too early (I thought it was more like 8 weeks-- my transplants were still very small when I set them out last year).  I'm writing back with an unfortunate update: The other tomato seedlings (NOT the Glaciers) that I previously thought were fine ... are not fine :(  Many are losing lower leaves--they wilt and fall off--and the top leaves, although they look good & green, are flimsy and some are drooping. I am seeing some white circles on stems. Do you think this is a fungus? Do I have to throw them away and buy starts? Might they survive if I chop the stem above the white circles and try to re-root them in water?I am including some more photos. Thanks!!

responder: The Question Asker Replied April 25, 2023, 8:11 PM EDT
response: Or could it be edema ?? Some of the tomatoes seem to have raised bumps on the leaf veins and stems. one more picture attached. https://gardening.usask.ca/articles-and-lists/articles-disorders/disorder-edema.php (I am currently in the master gardener class, and I am desperate to know what is ailing my tomatoes!)

responder: The Question Asker Replied April 25, 2023, 8:12 PM EDT
response: (sorry, here's the photo)

responder: Susan, UVM Extension Master Gardener Volunteer  Replied April 26, 2023, 2:29 PM EDT
response: Rachael:  After receiving your new update today, I reached out to Ann Hazelrigg for her thoughts on your tomato problem.  Here is what she had to say: Tomatoes are so weird. They do all sorts of things as seedlings it seems. The important thing with seedlings is to look at the new growth (sounds like that is fine and has good size/color). That tells me the roots are probably good (but she could also check those for white fibrous healthy roots). If she is seeing wilting of new leaves, it could be a factor of dryness/too close to lights or root issues. Do they recover when lights are off or when they are watered? Do the roots look good? If both new growth and roots look good, those first (older) leaves are not important. They often die, look bad, etc. because the plant is kind of "dumping" them in favor of the new growth. she can clip those off and stay the course. the plants should grow out of it just fine. I would watch the Glaciers a bit. I would not be concerned as long as the new growth is coming out strong and healthy. If not, please let us know. I was given tomato seeds at Christmas and they were just recalled by the company (not Johnnys) because they found they were infected with tomato brown rugose virus, a new bad virus in tomatoes. We were advised to destroy them. https://www.canr.msu.edu/news/tobrfv-a-new-concern-for-tomato-and-pepper-producersThe white circles could be edema but i would need a better picture. This is common in young seedlings when they do not have enough light and too much water. They will grow out of the abiotic disorder.  Hope this helps.  (Interesting about the new tomato brown rugose virus, and also interesting that the company would recall the seeds).   So, hopefully, the plants will grow out of the problem.  Don't give up on them yet! Sue