Question

The optimum temperature for the ideal vegetative growth of wheat

• A. 4-6 \(^\circ\)C
• B. 10-16 \(^\circ\)C
• C. 16-22 \(^\circ\)C
• D. 22-28 \(^\circ\)C

Hint:

Wheat is a cool-season C\(_3\) crop.
Its optimal temperature ranges follow a logical progression:
- Germination: 20-25 \(^\circ\)C (fastest) but grows at lower temps.
- Tillering/Vegetative: Cool (16-22 \(^\circ\)C).
- Maturity: Warm and dry (20-25 \(^\circ\)C).

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Wheat (Triticum aestivum) is a temperate (Rabi) crop that requires distinct temperature ranges for different physiological growth stages.
These stages include germination, tillering, vegetative growth, flowering, and grain filling.
Detailed Explanation:
Temperature is a critical environmental regulator of wheat development:
- The minimum or cardinal temperature for wheat germination is around 3 to 4 \(^\circ\)C.
- Ideal tillering occurs in cooler environments, specifically between 16 and 20 \(^\circ\)C.
- For active vegetative growth and photosynthetic accumulation, the plant requires slightly warmer, moderate temperatures ranging from 16 to 22 \(^\circ\)C.
- Temperatures exceeding 25 to 30 \(^\circ\)C during the vegetative stage can reduce tillering, accelerate development, and cause premature flowering, which ultimately decreases biomass and grain yield.
- During the grain-filling (ripening) stage, a slightly warmer temperature of 20 to 25 \(^\circ\)C is optimal, though heat stress above 30 \(^\circ\)C can cause shriveled grains.
Therefore, the range of 16-22 \(^\circ\)C is identified as the optimum for vegetative growth.

Step 2: Final Answer:
The optimum temperature for the ideal vegetative growth of wheat is 16-22 \(^\circ\)C.