A farmer is interested to cultivate cucumber plants in his field. Then suggest him the correct plant growth regulator which can induce more number of female flowers in those plants?

Options

A. Ethylene
B. Abscisic acid
C. Gibberellins
D. Cytokinins

Answer

To answer the question about which plant growth regulator can induce more female flowers in cucumber plants, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Requirement**: The farmer wants to cultivate cucumber plants and is specifically interested in increasing the number of female flowers.

2. **Identify Plant Growth Regulators**: We need to evaluate the different plant growth regulators available and their effects on flower sex expression in cucumbers.

3. **Evaluate Each Option**:
- **Option 1: Ethylene**: Ethylene is known to promote female sex expression in flowering plants. It increases the number of female flowers while reducing the number of male flowers. This makes it a suitable choice for the farmer's needs.
- **Option 2: Abscisic Acid**: This plant growth regulator does not influence sex expression in flowers. Its primary role is in processes like leaf and fruit abscission, making it an unsuitable option for this purpose.
- **Option 3: Gibberellins**: Gibberellins are known to promote male flower development and help in seed germination. Therefore, this option does not meet the farmer's requirement for increasing female flowers.
- **Option 4: Cytokinins**: While cytokinins promote cell division and growth, they do not have a direct effect on the sex expression of flowers. Thus, this option is also not suitable.

4. **Conclusion**: Based on the evaluation, Ethylene is the plant growth regulator that can effectively induce more female flowers in cucumber plants.

### Final Answer:
The correct plant growth regulator to suggest to the farmer for increasing the number of female flowers in cucumber plants is **Ethylene**.

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