You most likely got seed that was treated with a fungicide. Most commercially vended seed is treated. Many mail order companies that cater to home gardeners sell untreated seed although those who also vend to farmers will offer a choice of treated or untreated seed. The treated seed are better for emergence as it prevents rots and other fungal attacks on the seed itself. Once the plant is on its own, it does help but is not a cure all. I suspect that you had an attack of smut as the corn was earing out. Here is a link that might be useful: corn smut

If you are interested. Please scroll to bottom to see those no longer available. John Here is a link that might be useful: seed offering

I think you maybe reading too much into the linked article. They are offering you general guidelines, not any absolutes. So just to be clear I am not saying it isn't in soil, it is. It is all soil. I am saying that it isn't ONLY in the soil. It is also in the air and on surfaces all around you. Soil-less potting mix starts out at the factory as sterile. (Bales of peat do not.) During transport, storage, and once you open the bag it is no longer sterile. The extension offices are quite right in saying start out with a sterile soil-less mix. That improves your odds. But they are not saying that you still can't get damp-off even when you do. That is an important distinction. What I am trying to tell you is the fungus spores, just like all other fungus is in the air all around us. The only way you could prevent the fungus from coming in contact with your plants is by doing the whole process in a vacuum. You can't so there is no need to dump out mixes because the new you get will quickly also be contaminated. But it isn't the inactive floating-around fungus spores in the soil or in the air or on the container that do the damage. They just lie there, dormant, unless they are given the conditions they need to go active, to grow and replicate and produce the toxins that do the damage. Deny any fungus spore acidic pH, humidity, excess moisture, and expose it to good air circulation and it remains dormant and eventually dies. <Knowing that my plants are going to start off under the lights, would you recommend switching back to my smaller 72-count cells, or should my 50-counts work equally well as long as I go more by the weight and not soil appearance to judge dryness?> I don't think it makes any difference. We start all our plants in the greenhouses in bulk flats and then transplant to 6 packs or other larger containers depending on planned sale form. Many times I have started 20-30 tomato seeds in each cell of a 4 pack when I'm only germinating a small number of the variety. That way I can get 100-200 plants going in a small space. But as long as I use a soil-less potting mix that is pH balanced, keep good air circulation going, and limit the water there are no problems. Dave

The common cause of damp-off is OVER-watering. Overly wet soil that is kept consistently too wet is ideal for damp off to develop. Keeping soil lightly moist until germination is fine but once germination happens you need to cut back on the watering. And I think you'll find most will agree that watering most any crop even daily, much less 2x a day, is over-watering. ;-) The goal is deep watering (longer period of time) and much less frequently. Depending on where you live and your climate you may easily find that 1x per week is sufficient. Dave