Sexual reproduction refers to the process that the sperm of bisexual germ cells combine with eggs to form fertilized eggs, and the fertilized eggs develop into new individuals. Asexual reproduction refers to the process of directly producing new individuals from the mother without the combination of hermaphroditic germ cells. The way in which plants propagate with vegetative organs such as roots, stems and leaves is called vegetative propagation. Artificial asexual propagation methods include grafting, cutting and layering.

So the answer is: nutrition.