[A]: Rate of transpiration is high in low wind velocity.
[R]: Wind removes humid air from around the leaf due to which transpiration is high.

Options

A. If both A and R are true and R is the correct explanation of A
B. If both A and R are true but R is not the correct explanation of A
C. If A is true and R is false
D. If both A and R are false

Answer

To analyze the statements provided in the question, we will break down the concepts of transpiration and the effects of wind velocity on it.

### Step-by-Step Solution:

1. **Understanding Transpiration**:
- Transpiration is the process through which water vapor is lost from the aerial parts of the plant, primarily through small openings called stomata located on the leaves.
- This process is essential for the plant as it helps in nutrient uptake, cooling, and maintaining turgor pressure.

2. **Factors Affecting Transpiration**:
- Several factors influence the rate of transpiration, including light intensity, temperature, humidity, wind velocity, and soil moisture.
- Among these, wind velocity plays a significant role in determining the rate of transpiration.

3. **Analyzing Statement [A]**:
- The statement claims that "Rate of transpiration is high in low wind velocity."
- This statement is incorrect. When wind velocity is low, the air surrounding the leaves becomes humid because the moisture released from the leaves does not disperse quickly. This high humidity around the leaves reduces the concentration gradient for water vapor, leading to decreased transpiration.

4. **Analyzing Statement [R]**:
- The statement states that "Wind removes humid air from around the leaf due to which transpiration is high."
- This statement is correct. When wind velocity is high, it removes the humid air surrounding the leaves, allowing drier air to replace it. This increases the concentration gradient for water vapor, promoting higher rates of transpiration.

5. **Conclusion**:
- Since statement [A] is false and statement [R] is true, the overall conclusion is that the assertion (A) is incorrect while the reason (R) is correct.

### Final Answer:
- **Assertion [A]**: False
- **Reason [R]**: True