Yellowing of **young leaves** (chlorosis of young leaves) suggests deficiency of which element?
ANitrogen (older leaves first)
BIron — Fe is immobile; deficiency hits new tissues first
CPhosphorus
DMagnesium
Answer & Solution
Correct answer: B. Iron — Fe is immobile; deficiency hits new tissues first
Fe is immobile in phloem ⇒ deficiency hits YOUNG (newly forming) tissues. Symptom: interveinal chlorosis of new leaves. Fe is needed in chlorophyll biosynthesis (though not part of chlorophyll structure — Mg is). Common in alkaline/calcareous soils.
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