Question

Which one of the following is an immobile nutrient in plants?

• A. Nitrogen
• B. Potash
• C. Calcium
• D. Iron

Hint:

Immobile nutrients in plants: Calcium ($Ca$) and Boron ($B$) (deficiency appears on terminal buds); Highly mobile: $N, P, K, Mg$ (deficiency appears on older lower leaves).

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Plant nutrients are classified as mobile or immobile based on their phloem transport and redistribution capacity.

Step 2: Detailed Explanation:
Calcium ($Ca^{2+}$) and Boron ($B$) are structurally bound in cell walls (calcium pectate in middle lamella) and are completely immobile in plant vascular tissue.
Because they cannot be translocated from older to younger tissues, deficiency symptoms of calcium appear first on the emerging apical buds and terminal leaves.
In contrast, Nitrogen ($N$), Potassium ($K$), and Magnesium ($Mg$) are highly mobile.

Step 3: Final Answer:
Hence, calcium is an immobile nutrient in plants.