In the first picture you can see where the downforce on this planter wasn't working properly. This led to corn being planted to about half the desired depth. This corn is going to come up but will have shallow developed nodal roots which will hinder the plant and probably yield. Emergence will also be uneven. These plants aren't showing any frost damage as they hadn't emerged until recent rains and weren't out of the ground. 

The second pic shows where the downforce was working correctly and seeds were placed at the desired depth. This corn has also been through a frost as evidenced by the burnt leaves. It will come through this ok as the growing point is not above the soil surface yet.