Layering and its types

December 4, 2018

It is one of the artificial methods of asexual reproduction.
In this method, the roots are developed on the stem while the stem is still attached to the parent plant.
This method is commonly used in jasmine, magnolia, strawberry, raspberry, etc.
Many plantlets can be produced in a short period of time.
It is induced artificially by bending the branch to the ground and covering it with the moist soil.
The apical part of the stem produces leaves whereas the underground part produces the roots.
Later the layered branch is separated from the parent plant.

Types of layering

A) Simple layering

In this method, a low growing stem of more than one year age is bent downward and the target region is buried in the soil.
A few inches of the leafy stem must remain above the ground for the bent stem to grow into a new plant.
The buried portion of the stem develops roots after 2-3 months when watered regularly.
When the stem develops roots, it is separated from the parent plant and kept in nurseries.
Plants like lemon, citrus, etc. are propagated by this method.

B) Compound layering

The entire low growing stem is bent downward and buried in the soil in this method.
Its tip should be out of the soil.
The stem should be watered regularly so that the nodes produce new plantlets.
This method is commonly applied in apples, pears, walnuts, etc. to produce many plantlets in a short period of time.

C) Tip layering

The tip of the stem of a plant is buried in the soil to develop new plants in this method.
About a 5 to 8 cm long tip of the stem is buried in the soil and watered regularly.
When the tip develops roots, the portion of the stem is separated from the parent plants after 3-4 months.
This method is commonly applied in raspberry, blackberry, etc.

D) Mound or stool layering

Ground layering, or mound layering is the typical propagation technique.
The original plants are set in the ground with the stem nearly horizontal, which forces side buds to grow upward.

Image source: propgifas

After this, the original stem is buried up-to 20 to 25 cm from the ground.
At the end of the growing season, the side branches will develop roots and can be separated after one year.

E)Air layering

The target region of the stem is wounded or a strip of bark is removed and then encased in a moisture retaining medium, such as a moss or cloth.
It is further surrounded in a moisture barrier such as a plastic film.
Rooting hormone i.e. IBA(Indole -3- butyric acid) is often applied to encourage the growth of roots.
The wounded portion develops roots within 4-8 weeks.
Then, the portion is separated from the parent plant and planted.
Air layering is the most popular method of artificial vegetative propagation.