Phosphorus Deficiency Phosphorus is a mobile element. Initial symptoms of phosphorus deficiency begin with the plant appearing darker green overall, with a reduction in plant growth, leaf size, and stem thickness.
Expected symptoms include:
Irregular spotting along leaf margins, turning necrotic
Purplish to red pigmentation on leaf margins, older leaves, or stems
Marginal spotting on older leaves along the leaf margin.
Healthy, phosphorus-supplied plant.
Irregular brown spots will form on leaf margins during early stages of phosphorus deficiency.
During moderate phosphorus deficiency, the appearance of necrotic brown spots persists and moves beyond leaf margins.
Severe phosphorus deficiency leads to severely stunted plants and leaf death of oldest leaves.