Erratic Emergence Due to Shallow Planting

During late May, we visited this Lancaster County corn field that exhibited a severe case of erratic and late emerging corn.
Erratic Emergence Due to Shallow Planting - Articles
Erratic Emergence Due to Shallow Planting
Variation in emergence within the row.
Normally the mesocotyl should be about 0.75 inches long on corn that was planted 1.5 inches deep.