Which condition favours guttation

Options

A. High humidity
B. Low humidity
C. More transpiration
D. Bright sunlight

Answer

**Step-by-Step Solution:**

1. **Understanding Guttation:**
- Guttation is the process where water oozes out from the tips or margins of leaves. This typically occurs in the early morning hours.
- The water loss occurs through specialized structures called hydathodes, which are located at the leaf margins.

2. **Role of Hydathodes:**
- Hydathodes are responsible for the loss of water during guttation. They release not just water, but also dissolved salts (both organic and inorganic) present in the xylem sap.

3. **Conditions for Guttation:**
- Guttation occurs when the rate of transpiration (water loss through evaporation) is lower than the rate of water absorption by the roots.
- This situation creates a positive root pressure, which pushes excess water out of the hydathodes.

4. **Analyzing the Given Options:**
- **High Humidity:** In conditions of high humidity, the rate of transpiration decreases because the air is already saturated with moisture. This leads to a situation where water absorption can exceed transpiration, favoring guttation.
- **Low Humidity:** Low humidity increases the rate of transpiration, which would not favor guttation as more water is lost than absorbed.
- **More Transpiration:** An increase in transpiration means that water loss is greater than absorption, which would inhibit guttation.
- **Bright Sunlight:** Bright sunlight typically increases transpiration rates due to higher temperatures and light intensity, which again would not favor guttation.

5. **Conclusion:**
- Among the options provided, high humidity is the condition that favors guttation because it results in lower transpiration rates, allowing for excess water to be pushed out through the hydathodes.

**Final Answer: High Humidity (Option A)**

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