1. Define layering ?
⦿Stems still attached to their parent
plants may form roots where they
touch a rooting medium. Severed
from the parent plant, the rooted stem
becomes a new plant.
2. Stems still attached to their parent plants may form roots where they
touch a rooting medium. Severed from the parent plant, the rooted
stem becomes a new plant.
This method of vegetative propagation, called layering, promotes a
high success rate because it prevents the water stress and
carbohydrate shortage that plague cuttings.
Some plants layer themselves naturally, but sometimes plant
propagators assist the process. Layering may be enhanced by
wounding one side of the stem or by bending it very sharply. The
rooting medium should always provide aeration and a constant supply
of moisture.
3. 1. Dig a hole 3 to 4 inches deep.
2. Insert the shoot tip and cover it with soil.
3.The tip grows downward first, then bends sharply and grows upward.
4.Roots form at the bend, and the recurved tip becomes a new plant.
5.Remove the tip layer and plant it in the early spring or late fall.
6.Examples: purple and black raspberries, trailing blackberries.
4. 1. Bend the stem to the ground.
2. Cover part of it with soil, leaving the last 6 to 12 inches exposed.
3. Bend the tip into a vertical position and stake in place.
4. The sharp bend will often induce rooting, but wounding the lower side of the
branch or loosening the bark by twisting the stem may help.
5. Examples: forsythia, honeysuckle.
5. 1. This method works for plants with flexible stems.
2. Bend the stem to the rooting medium as for simple layering, but alternately
cover and expose stem sections.
3. Wound the lower side of the stem sections to be covered.
4. Examples: heart-leaf philodendron, pothos
6. 1. Cut the plant back to 1 inch above the ground in the dormant season.
2. Mound soil over the emerging shoots in the spring to enhance their
rooting.
3. Examples: gooseberries, apple rootstocks.
7. 1. Air layering is used to propagate some indoor plants with thick stems, or to
rejuvenate them when they become leggy.
2. Slit the stem just below a node.
3. Pry the slit open with a toothpick.
4. Surround the wound with wet unmilled sphagnum moss.
5. Wrap plastic or foil around the sphagnum moss and tie in place.
6. When roots pervade the moss, cut the plant off below the root ball.
14. Contd.
• the stem or root which is rooted
is called a layer
• the layer is removed from the
plant only after rooting has
taken place
15. Contd.
• Layering is the process of
developing new plantlets in
which root formation takes
place on layered portion
of stem before they are
severed from mother plant.
16. Principles of Layering
• Through notching or girdling,The
downward tranlocation of carbohydrates,
hormones and other organic substances is
interrupted by the removal of the bark .
• This carbohydrates, hormones and other
organic substances are accumulated in the
girdled site where dormant adventitious
buds regenerates and give rise to root.
17. Simple Layering
• a branch from the parent plant
is bent to the ground
• covered with soil at one point
• terminal end remains exposed
39. LAYERING
Definition:
It is a technique of propagation in which a portion of plant is faced to the
produce adventitious root while it still remains attached to mother plant.
40. Layering
⚫A branch of a plant is bent over and pinned to the
earth at a node
⚫When roots develop the branch is separated from the
parent plant.
⚫Useful for the propagation of woody plants
⚫e.g. blackberry, gooseberry.
41.
42. ADVANTAGES
It is an effective means of propagating species that usually do not root easily by
cuttings as in mango, kumquat, filberts and litchi.
It is the best method of propagation of plants, which reproduce naturally by
layering e.g., black berries, black raspberries, etc.
It does not require precise control on water, relative humidity or temperature as is
required for other methods of propagation.
It is easy to perform and does not require much facility.
It is possible to produce large sized plant with layering within a short time.
Layering is useful for producing relatively a smaller number of plants of good
size with minimum propagation facilities.
43. DISADVANTAGES
It is a costlier technique in areas where labour availability is problem.
It is not possible to produce large number of plants within short time.
The plants produced through layering have usually small and brittle roots.
In layering, the beneficial effects of rootstocks on the scion cultivar can’t
be exploited.
The mortality rate in layers (particularly air layers) is usually high.
44. PRINCIPLES OF
LAYERING
HOW ROOT FORMATION TAKES PLACE IN
LAYERS?
Girdling
Girdling is removing the bark and phloem tissues from a stem.
The stem remains alive because water and nutrients can still travel in the xylem.
This treatment is used in propagation because it can halt the downward flow of
auxin, so it accumulates at the site of girdling and rooting occurs in these areas
even though the stem is attached to the parent plant.
Water and nutrients are supplied to the layered shoots, because the stem is not cut
and the xylem remain intact.
This has how the root formation takes place in ground, serpentine and air-
layering.
45. Etiolati
on
Etiolation is development of plants or plant parts in the absence of light.
The absence of light is favourable for initiation of root primordia in the stem
tissue.
This is how root formation takes place in round and trench layering.
46. FACTORS AFFECTING THE SUCCESS
BY LAYERING
Stem treatments
Etiolation treatment
Physiological condition of the mother plant
Rejuvenation of the stock plant
Treatment with growth regulators
Nutrition
The environmental conditions
47. METHODS OF LAYERING
SIMPLE LAYERING
Simple layering is perhaps the easiest and most efficient method of layering
which is practiced in a great variety of woody plants without disturbing the
parent plant to any extent.
For making simple layers, rapidly growing shoots are first trimmed off side
branches and leaves for 10-20 cm behind the tip; the shoot is then bent to
ground level and covered with 5-7.5 cm of soil, leaving the tip of the shoot
exposed above the soil.
If the shoot comes out of the soil, it should be pegged down to the soil.
The soil around the buried stem is kept reasonably moist, especially during
the dry period.
Sometimes a notch or a girdle or a ring is made to the stem before burying
it to the soil.
48. This operation interrupts the downward movement of metabolites generated by
the leaves, resulting in accumulation of carbohydrates and hormones above the
notch, girdle or ring which ultimately stimulate the root formation.
In most plants, rooting is complete within 4-8 weeks.
The rooted layer is severed from the stock plant and kept in a pot in the nursery
for about a year before planting it in the final site.
E.g., lemon, black berry, grape, etc.
49. TIP LAYERING
Tip layering is practiced in such plants which have got trailing type of shoots, in
tip layering, growing tips of such plants are bent down and buried in the soil to a
depth of 5-7.5 cm or they may be inserted in pots.
The covered portion becomes etiolated and swollen, and strikes root within 2-3
weeks.
The rooted layer is then severed from the mother plant and transplanted either in
a permanent location or in the nursery.
E.g., blackberries, raspberries, gooseberries, currant, etc.
50. SERPENTINE LAYERING OR COMPOUND
LAYERING
This is also very easy to perform and is practiced in plants which have long
slender shoots like Jasminum or Clematis.
Stems of these plants are laid in the ground and alternately covered and exposed
over their entire length.
Sometimes the shoots are layered into pots sunk in the ground.
A slanting cut of about 5 cm long is given at a point where the shoot is to be
layered sometimes ringing or girdling is also dose.
Roots strike at or in close proximity to the node that is covered and new shoots
arise from the buds which are not covered.
E.g., strawberry.
51. TRENCH OR CONTINUOUS LAYERING
In trench layering, the branch is placed in a shallow trench and is
covered for its
• entire length, leaving only the terminal portion exposed.
Trench layering has the advantage of producing many plants per
branch.
When the root formation is complete, the soil is removed aroun
the layered shoot, and the rooted layers are cut off from the origin
stock plant.
Trench layering can be adopted in the vegetative propagation of
rootstocks of
52. MOUND OR STOOL LAYERING
Mound (stool) layering consists of cutting back the stem of a plant to the ground
during the non-growing season and covering the basal portion of the newly
developing young shoots in the spring with a mound of soil.
Covering with soil keeps the shoots etiolated and encourages root formation.
Mounding should be done with moist soil.
Sometimes to encourage root development, ringing or girdling at the base of the
young shoot and application of root-promoting substances are practiced.
E.g., apple root stock, pear, peach, etc.
53. Mound or stool layering: (a) the top is removed, (b) soil is heaped around the
young shoots arising on the topped stump, (c) formation of roots at the bases of
shoots, (d) removal of rooted layers.
54. AIR-LAYERING
This method is also known as Chinese layerage, pot layerage, marcottage and
gootee.
Air-layering is very popular and practiced in a wide range of plants, because the
method is easy to perform, does not require any specialized equipment and does
not disturb the plant.
Generally, long, one- to two-year-old shoots are used for air-layering.
First, the leaves are removed from the base of the selected shoot, then the stem
is given a notch or is girdled by removing a ring of bark about 2-3 cm wide.
The girdle helps in building up high carbohydrate and hormone reserves which
are necessary for easy and profuse rooting.
The cut surface is sometimes treated with hormones to bring about further
improvement in rooting.
The ringed or girdled area is then covered with a handful of moist soil.
55. This ball of earth is again covered with moist sphagnum moss, wrapped
with the polythene sheet and the two ends are then tied.
The polythene film used for wrapping retains moisture and allows gaseous
exchange.
Air-layering is usually done either in spring or in monsoon.
Depending on the species, rooting takes place within 4-8 weeks.
The rooted layer is separated from the parent plant in two or three stages to
reduce the stock of sudden separation.
The first cut, V-shaped and going in half way through the stem, is given
about 2.5 cm below the point of root emergence.
The second cut which is given to deepen the first one is given a week later.
A few days later the final cut is given, separating the layer from the mother
plant.
56. The rooted layers are either planted in pots or in the nursery beds in a shady
place until they are fully established and show renewed growth.
E.g., guava, pomegranate, etc.
57. REFERENCES
Plant propagation and nursery management by R. R. Sharma and Manish
Srivastav.
Propagation of tropical and subtropical horticultural crops by T. K. Bose, S.
K. Mitra, M. K. Sadhu, P. Das, D. Sanyal.
Fundamentals of horticulture by Jitendra Singh.
Basic concepts of fruit science by Neeraj Pratap Singh.
www.leavingcertbiology.net.
www.online-sciences.com.
www.majordifferences.com.
