Nitrogen is essential for corn plant growth, being one of the main building blocks of proteins. Therefore if the initial plant growth slows, if they are slow to come to flower and have thin stalks, there might be an indication of a nitrogen deficiency.
Young corn plants are also most likely deficient in potassium if they are slow to develop. Potassium deficiency increases the susceptibility to stalk rot leading to shorter crops.
When corn plant growth is severely stunted – leaves are thinner than normal, wrinkled and weak, it indicates a boron or manganese deficiency.
In case of a copper deficiency the tips of the new unfolding leaves are also dried-out and the stalk is often soft and limp.