Which method involves cutting a woody stem in a way that resembles a shield?

The method that involves cutting a woody stem in a way that resembles a shield is known as heal cuttings. In this technique, a slanting cut is made on the stem, and a portion of the bark is retained to support the developing new plant. This “shield” shape helps in providing a large area for the formation of callus and roots when placed in a suitable medium. The bark's presence helps facilitate the healing process, which is critical in the rooting phase.

Heal cuttings are primarily used in the propagation of certain woody plants and are effective because they establish a direct connection with the parent plant’s vascular system. This method ensures a higher success rate for the cuttings as they can draw nutrients and moisture during the initial stages of root development.

Other methods listed, such as cane cuttings, leaf petiole cuttings, and single-eye cuttings, utilize different plant parts or cutting techniques that do not resemble the shield shape characteristic of heal cuttings, thus distinguishing them from this specific method.