One of the commonly used plant growth hormone in tea plantations is

Options

A. Abscisic acid
B. Zeatin
C. Indole - 3 - acetic acid
D. Ethylene

Answer

**Step-by-Step Solution:**

1. **Understanding Plant Growth Hormones**: Plant growth hormones, also known as plant growth regulators (PGRs), play crucial roles in regulating various physiological processes in plants, including growth, development, and responses to environmental stimuli.

2. **Identifying the Options**: The question provides four options:
- Acetic acid
- Zeatin
- Indole-3-acetic acid
- Ethylene

3. **Analyzing Each Option**:
- **Acetic Acid**: This is not a plant growth hormone; it is a simple organic acid and does not play a significant role in plant growth regulation.
- **Zeatin**: This is a type of cytokinin, which is involved in promoting cell division and growth, but it is not the primary hormone used in tea plantations.
- **Indole-3-acetic Acid (IAA)**: This is a natural form of auxin, which is crucial for promoting apical dominance and influencing growth patterns in plants. It helps in the development of new leaves and fruit.
- **Ethylene**: This is a gaseous hormone that primarily regulates fruit ripening and other processes but is not specifically used for promoting growth in tea plantations.

4. **Understanding the Role of Indole-3-acetic Acid in Tea Plantations**:
- Indole-3-acetic acid promotes apical dominance, meaning it encourages the growth of the main stem or shoot. In tea plantations, the apical parts of the plants are often pruned to encourage the growth of lateral buds, which leads to a bushier plant and ultimately increases the yield of tea leaves.

5. **Conclusion**: Based on the analysis, the most commonly used plant growth hormone in tea plantations is **Indole-3-acetic Acid**.

**Final Answer**: Indole-3-acetic acid (Option 3).

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