Your crop is Nitrogen deficient.

• Nitrogen is required for production of chlorophyll, nucleic acids, and enzymes.
• Nitrogen is essential for plants to synthesize amino acids, which are the building blocks for protein synthesis.
• These amino acids are then used in forming protoplasm, which is used in cell division and also utilized in producing necessary enzymes and structural parts of the plant and can become part of the stored proteins in the grain.
• Form used by plants: NO-3 or NH+4