Your crop is Manganese deficient.

• Manganese plays a vital role in photosynthesis by aiding in chlorophyll synthesis
• Manganese plays an essential role in enzyme maintenance
• Manganese influences the uptake and assimilation of other nutrients in the plant
• Manganese affects energy budget by regulating carbohydrate metabolism.
• Reduction of nitrates in plants is only possible if sufficient manganese is present
• Similar to copper, manganese is important for immobilization of free oxygen radicals.
• Manganese is very immobile in plants, with deficiency symptoms appearing first on younger leaves.
• Form used by plants: Mn+2