Which of the following is not a growth promoting activity of plant growth regulators ?

Options

A. Cell division
B. Pattern formation
C. Seed germination
D. Abscission

Answer

To determine which of the following is not a growth-promoting activity of plant growth regulators, we will analyze each option provided:

1. **Cell Division**:
- Cell division is a fundamental process in growth where cells divide to increase in number. This is a clear growth-promoting activity as it contributes to the overall growth of the plant.

2. **Pattern Formation**:
- Pattern formation refers to the developmental process where cells differentiate and organize into specific structures and patterns. This process is essential for the proper development of plant organs and is also considered a growth-promoting activity.

3. **Seed Germination**:
- Seed germination is the process by which a seed develops into a new plant. This process is crucial for the continuation of plant life and is a growth-promoting activity as it leads to the growth of new plants.

4. **Abscission**:
- Abscission is the process of shedding or dropping off of plant organs, such as leaves, flowers, or fruits. This process does not promote growth; instead, it often signifies the end of a growth phase for those organs.

Based on the analysis above, the option that is not a growth-promoting activity of plant growth regulators is **Abscission**.

### Final Answer:
**D. Abscission**