Question

why bulb is not a method of natural vegetative propagation
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Answer 1

Vegetative reproduction (vegetative propagation, vegetative multiplication, vegetative cloning) is a form of asexual reproduction in plants. It is a process by which new organisms arise without production of seeds or spores. It can occur naturally or be induced by horticulturists. Plant structures allowing natural vegetative propagation include bulbs, rhizomes, stolons and tubers. Grafting and budding are horticultural techniques used to join parts from two or more plants so that they appear to grow as a single plant.

its the answer...

Answer 2

Bulb is a method of natural vegetation actually it is a stem tuber which mostly occurs in onions.