Mycorrhizal association :

Options

A. increases absoption of phosphates
B. are benefical to roots of higher plants only
C. are absent in agricultural crops
D. are characteristic of monocots only

Answer

### Step-by-Step Solution:

1. **Understanding Mycorrhizal Association**:
- Mycorrhizae are symbiotic relationships between fungi and plant roots. This association is crucial for nutrient absorption, particularly phosphorus, which is often limited in soil.

2. **Analyzing the Statements**:
- The question presents several statements regarding mycorrhizal associations:
- They increase absorption of phosphate.
- They are beneficial to the roots of higher plants only.
- They are absent in agricultural crops.
- They are characteristic of monocots only.

3. **Evaluating Each Statement**:
- **Statement 1**: "Mycorrhizal association increases absorption of phosphate."
- This statement is **true**. Mycorrhizae enhance the plant's ability to absorb phosphorus from the soil.
- **Statement 2**: "They are beneficial to the roots of higher plants only."
- This statement is **false**. Mycorrhizal associations are found in a wide variety of plants, not just higher plants.
- **Statement 3**: "They are absent in agricultural crops."
- This statement is **false**. Mycorrhizae are present in many agricultural crops and contribute to their growth and yield.
- **Statement 4**: "They are characteristic of monocots only."
- This statement is **false**. Mycorrhizal associations are found in both monocots and dicots.

4. **Conclusion**:
- The only correct statement from the options provided is that mycorrhizal associations increase the absorption of phosphate. Therefore, the answer to the question is that mycorrhizal associations are beneficial for nutrient absorption, particularly phosphorus.