Phosphorus is relatively mobile in the plant, so symptoms usually appear on older leaves first, although overall development is also compromised.

Typical symptoms:
• Slow growth and stunted development.
• Older leaves with dull, dark green tones.
• Appearance of purple, reddish, or bluish pigmentation, especially on the undersides of leaves and stems.
• Poorly developed root system with few lateral roots.
• Delayed flowering and ripening.
• Small fruits and lower yield.

Phosphorus deficiency directly affects the plant's energy and vitality, making it weak and less able to withstand stress.

Developmental stages:
• Early: Older leaves with darker green than normal.
• Intermediate stage: Purple or reddish pigmentation on stems and veins.
• Advanced: Limited growth, short, and sparsely branched roots.
• Final: reduced flowering, poorly formed fruits and low productivity.