Chlorosis in nitrogen deficient plants appears

Chlorosis in nitrogen-deficient plants appears first in the mature leaves and then in the young leaves.
Nitrogen-deficient plants have stunted growth and reduced yield. In many crops nitrogen-related chlorosis begins from the old lower leaves, the leaf tip and midrib turn yellow but the leaf edges stay green.
As deficiency persists yellowing progresses to the upper leaves and leaf necrosis (dying of leaf tissue) occurs.