Question

Element contributing to the disease and draught resistance is ________________

• A. N
• B. K
• C. P
• D. C

Hint:

Think of potassium (K) as the "quality" and "defense" nutrient in crops. It regulates stomatal movement, which controls transpiration and helps the plant survive drought and resist diseases.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Essential plant nutrients play distinct biochemical and physiological roles in plant metabolism.
While some nutrients promote vegetative growth or energy transfer, others are critical for osmotic regulation and stress tolerance.

Step 2: Detailed Explanation:
Let us analyze the role of potassium (K) in plant stress tolerance:
- Potassium is a highly mobile macronutrient that does not become a permanent structural component of plant compounds.
Instead, it exists as a free ion (\(\text{K}^+\)) regulating cell turgor and osmotic potential.
- In drought conditions, potassium regulates the opening and closing of stomata.
Adequate potassium levels ensure that stomata close rapidly during water stress, minimizing water loss from transpiration.
- Potassium also strengthens cell walls and promotes the synthesis of proteins and cellulose, creating physical barriers that prevent pathogen penetration.
This makes the plant more resistant to diseases and lodging.
- In contrast, nitrogen (N) promotes rapid, succulent vegetative growth, which can increase vulnerability to pests, diseases, and drought when in excess.
Phosphorus (P) is essential for energy transfer (ATP) and root development, and carbon (C) is a basic structural building block obtained from \(\text{CO}_2\).
Therefore, potassium is the element that contributes most to disease and drought resistance.

Step 3: Final Answer:
Potassium (K) is the nutrient that contributes to disease and drought resistance in plants.