Answer & Solution
Answer: Option B
Solution:
The correct answer is Option B: CRI (Crown Root Initiation).
Here's why:
Understanding the Stages: Wheat plants go through several growth stages. Tillering, jointing, CRI (Crown Root Initiation), and flowering are all important.
Limited Irrigation Impact: When you can only irrigate once, you need to choose the stage where water stress will cause the MOST significant yield reduction.
Why CRI is Critical:
* The CRI stage (around 21 days after sowing) is when the plant starts developing its permanent root system.
* This root system is crucial for nutrient and water uptake throughout the rest of the plant's life.
*
Water stress during CRI severely limits root development, leading to stunted growth and reduced grain yield.
Why Other Options Are Less Critical (with only one irrigation):
*
Tillering: While important for plant density, water stress here is less damaging than at CRI, especially if later growth is supported.
*
Jointing: This is when the stem elongates. While water is needed, a good root system established during CRI is more fundamental.
*
Flowering: Important for grain formation, but if the plant suffered severely at CRI due to lack of water, the potential yield will already be significantly reduced, making a later irrigation less effective than one at the CRI stage.
In short, irrigating at the CRI stage gives the wheat plant the best foundation for healthy growth and maximum yield under limited irrigation conditions.
