it was all good and always has been. Not sure but it looks like you should fill your box up with more soil. I have planted 4 per square and get at least 1 good ear per stalk. Dixie was getting 2-4 ears per stalk...that is really something...http://thewealthyearth.com
Looking good and healthy though

the reason you got no corn is the plants where too close together and there were not enough plants.
if planting corn the whole 4ftx4ft box must be corn see the other corn thread.

I planted 1 packet of corn seed last year with 4 plants per sq. ft. It got really tall and tasseled, then flopped over in a heavy rain as it is shallow-rooted and the soil is so loose and fluffy in my raised bed. Spent a stressful hour out there with my hubby - I held the corn plants upright and he wove twine in the "french weave" fashion in and out of the plants and tied it to stakes at the ends of rows to set them upright again. They continued to grow and we did get some corn, though not every plant produced. Not sure if this is because they lost their "rooting" or just our cold northern Wisconsin summer was too short. I chose a much shorter variety for this year, hoping it will not flop over. But I just read that raccoons LOVE the shorter variety, easier to reach the corn. WAAAAAHHH!! Incidentally, I am also going to try "underplanting" squash or cukes amongst the corn this year, supposedly coons don't like walking through those. If you co-plant with pole beans, let the corn get a head start or the beans out-grow the corn!

I think the trouble here is that there is only one row. Most recommend at least 4 rows. That improves the chances of the tassels getting onto the silk of other plants. (pollunation). The wind may blow in any direction and 4 rows should cover all instances.....I should talk. I was raised on a corn farm and I can't grow corn to save by bippy.

I planted an entire 16' x 4' bed of corn, 4 per sq ft last year. Didn't get any edible ears, only a few very small ears with only a few kernels. My entire garden did poorly last year, weather and bad soil. I am going to try it again this year, but if it doesn't turn out, probably be the last year. If you have the space, it is fun to try. If you are short on space, I would use it for more productive crops.

I just let the farmers grow corn... I would rather use my space for crops that produce much much more in that same space.