Question

Whiptail of cauliflower is due to the deficiency of

• A. Copper
• B. Zinc
• C. Molybdenum
• D. Nitrogen

Hint:

Molybdenum is the only micronutrient whose availability *increases* as soil pH increases. Whiptail of cauliflower is a classic exam topic, so always associate "Whiptail" with "Molybdenum deficiency on acidic soils."

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Deficiencies of specific plant nutrients can cause characteristic physiological disorders and structural abnormalities.
Cauliflower (Brassica oleracea var. botrytis) is highly sensitive to certain micronutrient deficiencies, particularly on acidic soils.

Step 2: Detailed Explanation:
Whiptail of Cauliflower: This is a classic physiological disorder caused by Molybdenum (Mo) deficiency.
Molybdenum is a crucial cofactor for nitrate reductase, the enzyme responsible for converting nitrate to nitrite in plants.
When Mo is deficient, nitrate accumulates in plant tissues, and the normal synthesis of proteins and structural components in leaves is disrupted.
As a result, the leaf blades fail to develop properly, becoming severely stunted, distorted, and irregular.
The leaves are reduced to thin, strap-like structures resembling whips, leaving only the thick midrib intact.
This disorder is common on highly acidic soils (pH $< 5.5$) because Molybdenum availability decreases significantly as soil pH drops.
It is managed by applying sodium or ammonium molybdate or by liming the soil to increase pH.

Step 3: Final Answer:
Whiptail of cauliflower is caused by Molybdenum deficiency, which corresponds to option (C).