When propagating woody cuttings, why is a growth-promoting substance sometimes applied to the base?

Applying a growth-promoting substance, often referred to as rooting hormone, at the base of woody cuttings encourages the development of roots. This substance typically contains auxins, which are plant hormones that stimulate root formation. By enhancing root development, the cuttings can more effectively absorb water and nutrients, leading to a greater chance of successful propagation.

Additionally, while the primary purpose of these hormones is to facilitate rooting, they can indirectly aid in the healing process of the cuttings. The rooting hormone helps to expedite the natural healing that occurs at the cutting site, further increasing the chances of survival once planted.

Moisture conservation is another benefit associated with the application of growth-promoting substances, as the new roots can help maintain hydration for the cutting. However, this moisture retention is more of a supportive function rather than the main objective of using the growth-promoting substance.

Overall, the effectiveness of rooting hormones encompasses multiple benefits, which is why the answer includes all of these aspects as contributing to the success of propagating woody cuttings.