Which one does not affect apical dominance ?

Options

A. IAA
B. IBA
C. Gibberillins
D. Indole Acetaldehyde.

Answer

### Step-by-Step Solution:

1. **Understand Apical Dominance**: Apical dominance is a phenomenon in plants where the main central stem grows more strongly than the lateral stems. This is primarily due to the presence of certain plant hormones.

2. **Identify the Hormones**: The hormones that are typically involved in apical dominance include auxins, which are produced at the tip of the plant. The most common auxins are Indole-3-acetic acid (IAA) and Indole-3-butyric acid (IBA).

3. **Analyze the Options**:
- **IAA (Indole-3-acetic acid)**: This is a type of auxin and is known to promote apical dominance.
- **IBA (Indole-3-butyric acid)**: This is another auxin that also supports apical dominance.
- **Gibberellin**: This is a different class of plant hormone that does not play a role in apical dominance.
- **Indoleacetaldehyde**: This is a derivative of IAA and is also involved in apical dominance.

4. **Determine the Correct Answer**: Since gibberellin does not affect apical dominance, it is the correct answer to the question.

5. **Conclusion**: The hormone that does not affect apical dominance is **Gibberellin**.