What would cause my seedlings to look like this?
These are pictures of some artichoke and tomatoes I started. The artichokes germinated with curled, yellowish cotyledons. When new leaves appear, they quickly turn yellow, and some of them brown. Same with tomatoes - the cotyledons yellow before even forming true leaves. My parsley is showing symptoms too - with the cotyledons turning down. They seem to get worse when the sun is out - like the leaves "burn", or curl up.
There are no pests on these plants - and there is supposed to be no fertilizer in this seed starting mix - just peat, limestone, and perlite. I had similar symptoms last year that we thought was the fertilizer- but now the mix has none in it. Our water seems to be fine - with nothing out of the ordinary in our test results. Our soil PH is 6-7 - with our water about 7.5. I normally fertilize lightly with kelp / fish when first true leaves appear - but not sure if these will get to that point - or if feeding them will damage these guys more.
Last thing - we have them in greenhouses - that do not get above 80Â°, as we have the exhaust fans set to go on at 75Â°, with a night time low of 55-57Â°. We keep fans going all the time, to circulate air, and make sure the plants do not stay wet. I have never had damping off issues, and with the exception of the "bad" soil last year, have never had problems like this.
Any ideas? Disease? Contaminated peat moss? I am at a total loss - if anyone has experienced something similar - please share. We will be sending off soil to be sampled, but need to find out what is going on NOW!