Question

What is meant by Layering?? State it's 2 types and define it and also what is the difference between the two??? ??

Answer 1

Layering. (Science: botany, technique) a propagation method by which adventitious roots are caused to form on a stem while it is still attached to the parent plant.
Layering has evolved as a common means of vegetative propagation of numerous species in natural environments. Layering is also utilized by horticulturists to propagate desirable plants. Natural layering typically occurs when a branch touches the ground, whereupon it produces adventitious roots.

Two types are ground layering and air layering Ground layering Ground layering or mound layering is the typical propagation technique for the popular Malling-Merton series of clonal apple rootstocks, in which the original plants are set in the ground with the stem nearly horizontal, which forces side buds to grow upward[citation needed]. After these are started, the original stem is buried up to some distance from the tip. At the end of the growing season, the side branches will have rooted, and can be separated while the plant is dormant. Some of these will be used for grafting rootstocks, and some can be reused in the nursery for the next growing season's crop.

Ground layering is used in the formation of visible surface roots, known as "nebari", on bonsai trees.
Air layering In air layering (or marcotting), the target region is wounded by an upward 4 cm long cut and held open with a toothpick or similar, or a strip of bark is removed. The wound is then surrounded with a lump of moisture-retaining medium such as sphagnum moss or cloth, and then further surrounded by a moisture barrier such as plastic film tied or taped to the branch to prevent moisture loss or ingress of too much water as from rain. Rooting hormone is often applied to the wound to encourage root growth. When sufficient roots have grown from the wound, the stem is removed from the parent plant and planted, taking care to shield it from too much sun and to protect it from drying out until the new roots take hold. It can take the layer from a few weeks to one or more growing seasons to produce sufficient roots; this is largely dependent on the plant species and the vigor of the parent plant.