Corn seeds germinate rapidly directly in soil. For good polination, corn is usually planted in a rectangle. Therefore, direct seeding of more plants than you may have would likely overtake the transplants and do better with more corn.

Last week my late corn took a beating very similar in your pics and I figured that it's either early morning squirrels or late nite raccoons. I surrounded my plot with nylon netting but the varments were still getting into the corn chewing thru the nets and eating the pre-ripened ears like peeling bananas. I was wrong on both varment counts. I placed a large hav-a-hart trap in the middle of the corn plot (with ear inside) and the next morning I had a skunk in the trap with an ear eaten to the bone. I knew that skunks were stealing my grapes but apparently they love Ambrosia sweet corn too.

it doesn't look insect-related to me--i am often wrong, but it looks like a fungal problem connected to water on the leaves overnight. the one (miserable failure) time i grew corn, i had these same spots. the plant outgrows them.

From your initial description of the issues your plants are facing, I was leaning towards thinking your plants were having a root rot issue. I still sort of lean that way, but not as much as I was in the beginning. Root rot is very common on heavy, slow-draining clay and you have fast-draining sandy soil where it is much less common. The specific root rot I had in mind often progresses in a linear manner. For example, if it hits a row of shrubs, you'll see it move from one to another in a linear manner. However, in field crops it also progresses in a circular manner. However, you're in OKC and it is more common in the southern OK counties, and not so much in OKC, I think. If you did find the stringy growth I described in the root zones of dead plants, or observed a white spore mat on the soil surface near those plants, though, I'd go back to my original feeling that it sounds a lot like cotton root rot, which I just happen to have battled here in our heavy red clay. One question that would help rule out cotton root rot is this: when the leaves die, do they cling to the plant or do they drop? Cotton root rot can affect plants very suddenly, it affects over 2000 known species, it is very fast-acting (i.e. quick to kill plants), it moves in a linear or, in crops, in a circular fashion, and it is common in clay soil. So, it might not be your problem, but a similar root rot might be. Keep in mind, there's the disease type of root rot caused by specific fungal diseaes and there's the physiological kind of root rot caused by plants standing in water/wet soil until their roots literally rot and die. The folks at Horn's seemed to lean towards the physiological form of root rot when they expressed their opinion that your plants are being overwatered. You're the one who has to decide if they are right. I still think it is very hard for fast-draining sandy soil to stay wet enough to root rots. One way to figure out if the plants are dying because they are too wet is to dig up a dead plant and look at the roots. Do they look healthy and alive or dead? Since you have sandy soil, I think root knot nematodes could be an issue, but I don't have a lot of experience with them. If you have root knot nematodes, you'll see knots, galls or swellings on the roots of an affected plant that has died. You can google and find a photo of roots with root knot nematode damage. I am inclined to think you need to take a three-pronged approach. 1.) Feed your plants if they haven't been fed in the last couple of weeks. Fast-draining sandy soil that is being heavily watered may not be providing the plants with enough nutrition, and plants that are "hungry" or underfed are more vulnerable to diseases and to heat stress. 2.) Spray with a fungicide on a regular schedule as the fungicide labels direct. Watch to see if your plants improve. 3.) Treat for insects in whatever way you're comfortable using, but I am not convinced they are the issue. And then there is the watering issue. You want your plants to be in moist soil, and you want it to be as uniformly moist as possible. It is better to keep it somewhat moist at all times than to alternate between very dry and very wet because both those extremes stress plants. And, if it were the heavy April/early May rains that were the issue, I would have thought the plants would have showed symptoms long before the heat wave arrived last week. As long as you water with a sprinkler system, your plants are going to be more vulnerable to fungal diseases, so a regular preventative spraying program of fungicide during the growing system probably would be a good idea. You didn't mention if your beds are mulched, but if they aren't, they need to be. Mulching helps keep fungal spores in the soil from being carried up onto the plants by water splashing up when the sprinkler system is in use. I am a little worried about the roses. Look at the undersides of the leaves. Do you see spider mites? Both the fine webbing and the discolored leaves sound like spider mite damage. Look at the photos in the link below and see if they resemble your roses. The ones in the linked photos may be further along with the mites than yours are, but your plants still ought to look similar if it is mites. I don't really know what the answer is as far as plant death. I think it is still likely to be a fungal disease, but without seeing the plants can't rule root knot nematodes in or out, or anything else for that matter. Dawn Here is a link that might be useful: Spider Mites on Roses