Question

Interveinal chlorosis in crops is a typical characteristic of nutrient deficiency symptom of -

• A. Potassium
• B. Manganese
• C. Zinc
• D. Phosphorus

Hint:

Nutrient Deficiency Patterns:
- Interveinal Chlorosis: Manganese (Mn), Iron (Fe), Magnesium (Mg - on older leaves).
- Marginal Scorching: Potassium (K).
- Purple Pigmentation: Phosphorus (P).
- Rosetting Little Leaf White Bud: Zinc (Zn).

Answer 1

The Correct Option is B

Concept:
Plant nutrient diagnostic keys utilize visual deficiency symptoms to identify specific mineral shortages in crop plants.
Interveinal chlorosis is characterized by the loss of chlorophyll (yellowing) in the laminar tissue between the veins of leaves while the veins themselves remain dark green.
The position on the plant (older leaves, middle leaves, or younger leaves) and the specific interveinal patterning help pinpoint the deficient nutrient element.
Manganese plays a fundamental role in the oxygen-evolving complex of photosystem II and chloroplast membrane integrity.

Step 1: Role and Symptomatology of Manganese (Mn):
Manganese ($\text{Mn}^{2+}$) is essential for the photolysis of water in photosynthesis, nitrogen metabolism, and enzyme activation.
Because manganese is relatively immobile in plant tissues, its deficiency typically manifests on middle-to-younger leaves.
The classic symptom is pronounced interveinal chlorosis, where veins remain green and produce a characteristic checkered or netted appearance, often followed by grey speck symptoms (e.g., Grey speck of oat, Marsh spot of pea).

Step 2: Evaluating Other Options:
- Potassium (A): Deficiency causes marginal chlorosis and scorching/firing along leaf tips and margins on older leaves.
- Zinc (C): Causes "little leaf", rosetting, and broad bleached bands (white bud in maize) due to impaired auxin synthesis.
- Phosphorus (D): Imparts dark green foliage followed by purple/bronze pigmentation along veins on older leaves due to anthocyanin accumulation.

Step 3: Final Answer:
Hence, interveinal chlorosis with a distinct green vein network is a characteristic symptom of Manganese deficiency, corresponding to option (B).