Describe the process of air layering and its advantages.

• A. Propagation by seed in soil
• B. Grafting onto rootstock
• C. Air layering involves removing a stem and planting in water
• D. Inducing roots on a stem while still attached to the parent plant; advantages include high success rate and propagation of exact cultivars.

Answer: (D)

Air layering is a vegetative propagation method where roots are induced on a stem while it remains attached to the parent plant. You select a healthy stem, wound or girdle a small section to expose inner tissue, and surround that area with a moist rooting medium such as sphagnum moss or peat. The setup is sealed with plastic to keep moisture in, and sometimes rooting hormone is used to speed root formation. When a healthy root system has developed, you cut below the rooted section and transplant the new plant.

This approach has several advantages. It often has a high success rate because the new plant develops roots while still fed by the parent’s vascular system, producing a robust, well-established plant once separated. It also propagates exact cultivars, preserving the parent’s genetic identity, which is especially valuable for varieties that don’t root well from cuttings or from seed. Additionally, you can produce a sizable, mature plant more quickly than from seed, and you avoid the variability that can come with seed propagation or the need to graft onto rootstock. By contrast, propagating by seed introduces genetic variation and isn’t the same as cloning the parent, while grafting joins a scion to a rootstock, and removing a stem to plant in water describes a different form of cutting propagation rather than air layering.