When artificial methods of vegetative propagation are utilised?

Explanation

**Step-by-Step Solution:**

1. **Definition of Vegetative Propagation:**
- Vegetative propagation is a method of asexual reproduction where new plants grow from fragments of the parent plant. This can include roots, stems, or leaves.

2. **Artificial Methods:**
- Artificial methods of vegetative propagation refer to human-made techniques used to propagate plants. These methods include grafting, layering, cutting, and tissue culture.

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