Tomatoes Yellow Leaf Spots

[TyThePlantGuy]

Would anyone happen to kbow what these yellow spots are on my month old tomato seedlings? I haven't noticed them before. I noticed them recently after a deep watering. My tomatoes are inside under grow lights. I keep the nursery as clean as a nursery can get. I keep it ventilated as well.

[nickdub]

Doesn't look like anyhting to worry about to me. Are you giving them any fertiliser ?

[TyThePlantGuy]

Yes, Down to Earth, Vegetable Garden 4-4-4. I just recently gave them some Down to Earth, Fish Powder 12-1-1. I gave them the 4--4-4 last month it's a slow release. I gave them the 12-1-1 as a soil drench.

[ameno]

If anything, that may be too much fertiliser. At the very least, I think it's probably too much nitrogen. I don't usually feed my tomatoes at all until they start flowering (although I do repot them twice).

That won't be what's causing the leaf spotting, though. I imagine that's some sort of physiological condition, likely caused either by sun scorch or by something slightly caustic falling on the leaves (like, for example, your fertiliser when you apply it). Whatever caused it, as long as the new leaves are healthy then it's nothing to worry about.

[quanglewangle]

Agree that's a lot of nitrogen.

If the lights are powerful the spots could be scorch marks caused by water droplets acting like a lens.