The number of female flowers can be increased by the application of

Options

A. IAA
B. `C_(2)H_(4)`
C. Ck
D. All of these

Answer

To solve the question regarding how to increase the number of female flowers, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks which substance can be applied to increase the number of female flowers in plants.

2. **Identify the Options**: The options provided are:
- IA (Indole Acetic Acid, a form of auxin)
- C2H4 (Ethylene, a gaseous hormone)
- CK (Cytokinin)
- All of these

3. **Analyze Auxin (IA)**:
- Auxin is known to promote apical dominance, delay abscission (the dropping of leaves and fruits), and assist in root formation.
- However, it is not primarily associated with the promotion of female flowers.

4. **Analyze Ethylene (C2H4)**:
- Ethylene is a gaseous hormone that plays several roles in plant development.
- It is specifically known to promote the formation of female flowers in certain plants, such as cucumbers.
- This makes ethylene a strong candidate for increasing the number of female flowers.

5. **Analyze Cytokinin (CK)**:
- Cytokinins are involved in promoting cell division and delaying aging in plants.
- While they are important for growth, they do not specifically promote the formation of female flowers.

6. **Conclusion**: Based on the analysis, ethylene (C2H4) is the hormone that promotes the formation of female flowers. Therefore, the correct answer is option 2: C2H4 (Ethylene).

### Final Answer:
The number of female flowers can be increased by the application of C2H4 (Ethylene).

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