Phosphorus deficiency typically presents as what symptom?

• A. Older leaf yellowing
• B. Stunted growth with dark green leaves
• C. Interveinal chlorosis on young leaves
• D. Leaf curling

Answer: (B)

Phosphorus is essential for energy transfer and genetic material in plants, so when it’s deficient, growth slows and the plant remains stunted. Leaves often appear dark green, and in many crops you may even see a purplish or reddish tint on stems or undersides of leaves, especially in cooler conditions. This pattern—reduced growth with dark green foliage—fits phosphorus deficiency best.

Interveinal chlorosis on young leaves is more typical of iron deficiency, which disrupts chlorophyll formation. Yellowing of older leaves points toward nitrogen deficiency, where the plant redirects growth and foliage changes occur earlier on older tissues. Leaf curling can result from a variety of issues, not specifically phosphorus shortage.