What are common signs of nitrogen deficiency in plants?

• A. Interveinal chlorosis in young leaves.
• B. Yellowing of all leaves evenly with stunted growth.
• C. Pale green leaves (chlorosis), slower growth, and older leaves yellowing.
• D. Leaves curling upward.

Answer: (C)

Nitrogen is essential for making chlorophyll and proteins, and it moves easily from older leaves to new growth when scarce. Because nitrogen is mobile, the plant prioritizes the newer leaves, so the older leaves lose nitrogen first and yellow. The drop in chlorophyll from insufficient nitrogen causes pale green leaves, and overall growth slows since the plant can’t synthesize enough proteins for rapid growth. That combination—pale green leaves, slower growth, and yellowing of older leaves—is the typical sign of nitrogen deficiency. Other patterns, like interveinal chlorosis in new leaves or uniform yellowing with stunting, point to different nutrients or stresses, not nitrogen specifically.