Exudation' is due to

Options

A. O.P
B. Root pressure
C. Diffusion pressure
D. Transpiration pull

Answer

**Step-by-Step Solution:**

1. **Understanding Exudation**: Exudation refers to the process where water and dissolved substances are released from the plant, particularly from the cut surfaces of stems or leaves.

2. **Identifying the Causes of Exudation**: The question lists several potential causes: osmotic pressure, root pressure, diffusion pressure, and transpiration.

3. **Focusing on Root Pressure**: Among these, root pressure is a significant factor. Root pressure is generated when ions from the soil are actively transported into the vascular tissues of the roots.

4. **Mechanism of Root Pressure**: As ions are absorbed, water follows due to osmosis, increasing the pressure within the xylem. This positive pressure is what drives water upward through the plant.

5. **Observing Exudation**: Exudation can be observed in the early morning when the atmospheric moisture is high. When a stem is cut, water droplets can be seen oozing out due to the root pressure.

6. **Conclusion**: Therefore, the main process responsible for exudation is root pressure.

**Final Answer**: Exudation is due to root pressure.

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