HORTICULTURE 22

Laboratory Exercise No. 3a

Propagation by Air Layering and Cutting

INTRODUCTION

Asexual propagation is used to reproduce or multiply many horticultural

plants. Plants that are propagated asexually are genetically the same as the
mother plant. This is also called cloning. Although cloning is being talked
about a lot today, it is not a recent development. Farmers have been cloning
crop plants since before recorded history. One of the oldest clones in
existence is Thompson seedless grapes. The plant with the largest number of
daughter plants is the navel orange. All clones originate from a single plant
and ŵall of the plants that are propagated from it, asexually, are genetically
the same.Some asexually propagated crops that are grown extensively are:
tree fruits, cane fruits, strawberries, sugar cane, potatoes, sweet potatoes,
cassava, cranberries, and most herbaceous and woody ornamental plants.
Almost all the flower crops and green plants grown as greenhouse crops are
also propagated asexually. Plants are propagated asexually to preserve the
genetic characteristics of a particular plant; to propagate plants that do not
produce viable seeds (bananas, pineapple, seedless grape, etc.); to
propagate plants that produce seed that is difficult to germinate or has Avery
short storage life (cotoneaster, willow); and to bypass the juvenile stage of
plant growth when the plants will not flower and bare fruit (apple).

OBJECTIVES

To learn and develop the skills in the propagation of horticultural crops by

layering.

Materials

 Sharp knife
 Rooting medium
 plastic sheet/wrapper
 Tying material (string or adhesive tape)
 Rooting hormone (ANAA)
 Lemonsito tree or any plant available for marcotting
Procedure

A. Air layering

1. Prepare the following materials:

a. Sharp knife

b. Rooting medium (sphagnum moss, sawdust or a combination of garden

soiland rice hull ash-1:2 ratio).

c. plastic sheet (wrapper); plastic. Tying material (string or adhesive tape)

2. Select stem/branch about the size of an ordinary lead pencil or smaller

depending on the crop species that is healthy and as much as possible
without flowers/fruits. At approximately 1 foot from the tip of the shoot, make
a parallel cut on the bark about ½ to 1 inch or approximately equal to the
circumference of the stem/ branch. Remove bark and scrape the exposed
surface of the stem to ensure complete removal of the cambium layer in
order to prevent regrowth of bark before root formation takes place.

3. Root promoting substances may be applied especially at the upper edge of

the girdled stem. This can be done by wetting a piece of cotton with a
prepared solution of the hormone and wrapping or wiping it on the girdled
stem especially at the upper end. The solution can also be mixed/used to
moisten the rooting medium.

4. Position the wrapping material (plastic sheet) by folding it around the stem
enclosing the wound/cut. Tie securely using a string or plastic straw the
lowered of the wrapper at about 3 cm below the lower cut.

5. With the wrapper now forming a receptacle, place or fill it with about 2
handfuls of the rooting medium and then securely tie the upper end of the
wrapper. The medium should be sufficiently moist but not too wet. When
using garden soil, the moisture is enough if the imprint of the finger is left
and little cracks is observed but does not break (too dry) nor turn muddy (too
wet) when squeezed firmly in the hand.

6. When you see through the plastic film that sufficient roots are formed and
are already mature (in most cases yellowish in colour), cut the marcott just
below the ball of the rooting medium that holds the roots.

7. After cutting the marcot, remove the wrapper slowly as well as some of
the leaves and place in a pot or any suitable container with good potting
medium and having enough size to provide sufficient room for roots to
develop further.8. To determine the effects of rooting hormone, consider the
following treatments

T1 -With rooting hormone/substance

T2-Without rooting hormone/substance

RESULTS

TREATME No. Of Days of No. Of % Color Rootin

NT marcots rooting rooted rooting of g
marcot leaves density
s
T1 1 20 days 1 80% Green ++
T2 1 23 days 1 80% Green ++
Rooting Density:

+++ -many roots

+ + - few roots

+- very few

-none

DISCUSSION

Air layering is a propagation method used to encourage roots to form on a

stem while it is still attached to the parent plant. Here’s a general guide on
how to perform air layering: Select a Healthy Stem: Choose a healthy and
mature stem with a diameter of about ½ to 1 inch. Select a location on the
stem where you want roots to develop.Make a Slanting Cut: Make a slanting
cut approximately 4-6 inches below a node (where leaves emerge. The cut
should be about one-third to halfway through the stem. Apply Rooting
Hormone (Optional): Applying a rooting hormone to the cut area can promote
root development, but it’s optional. Wrap the Cut Area: Wrap the cut area
with damp sphagnum moss or a similar rooting medium. Cover the moss with
plastic wrap or a plastic bag, securing it above and below the cut. Secure the
Covering: Use string or twist ties to secure the covering tightly around the
stem, ensuring a good seal to retain moisture. Wait for Roots to Develop:
Roots usually take a few weeks to a few months to develop. Check
periodically by carefully opening the covering and inspecting the area.
Separate and Plant: Once you see sufficient roots (several inches long),
carefully cut the stem below the rooted section. Plant the rooted section in a
pot with well-draining soil or directly in the ground. Care for the New
Plant:Provide proper care for the newly propagated plant, including regular
watering and appropriate light conditions.

Remember that not all plants are suitable for air layering, so it’s good to
research and understand the specific requirements of the plant you’re
working with. This method is often used for woody plants and fruit trees.

GUIDE QUESTION

1. What are the advantages and disadvantages asexually propagation ?

Asexual propagation Is the controlled perpetuation of plants. Its objective

is to achieve an increase in number to preserve the essential
characteristic of a plant. Those crops that cannot produce seeds hence
cannot reproduce sexually will be propagated asexually. There are also
crops that can produce seeds, but for economic reasons, convenience and
expediency they are propagated asexually.Asexual propagation will be
practiced because most fruits and ornamental plants areheterozygous,
the genetic makeup of which are easily lost if propagated by
seeds.Asexual propagation is necessary to grow cultivars that rarely
produce viable seeds.In some crop species, asexual propagation is easier,
more rapid and economical toperform than by using seeds. Vegetative
propagated plants in general produceflowers and fruits earlier. Basically,
its advantages are:

 Quicker and more certain.

 Produces identical quality as the parent.
 Plants that do not have viable seed can be reproduced.
 Flowers produced are of superior quality.
 Desirable character of fruit can be maintained.

2. 2.What are the other methods of layering aside from air layering?
Describe each method.
1. Simple layer-can be accomplished by bending the low growing or
flexible part to the ground. Cover part with the soil leaving the
 remaining 6-12 inches above the soil. Bend the tip into a vertical
position and stick in place.
2. Tip layer-it is quite similar to simple layering. Dig a whole 3-4
inches deep. Insert the tip of a current season shoot and cover it
with the soil. The tip goes downward first then ben sharply and
grows upward. Roots form at the bend.
3. Compound or Serpentine layer-Bend the stem and the rooting
medium as for layering but alternately expose section of the
stem. These sections should have at least one bud exposed and
one bud covered with the soil. One is on the lower side of each
stem section to be covered. This method works well with
producing vine-like growth like grapes.
4. Mound or stool layering-useful in heavy stem. Closely branch
shrubs or rootstock of three fruits. Then, cut the plant back to
one inch above the surface in the dominant season. Dominant
buds will produce new shoots in the spring. Mount soil over
shoots as they grow so root will develop.
5. Trench layer-is similar to mound layering except that the plants
are initially placed horizontally in the stool bed. Trench layering is
the choice for those plants that have strong apical dominance
and do not form many shoots after an initial cutback.

3.What particular stage of the marcotting operation that is considered most

critical?

The most critical stage of the marcotting operation is by selecting the bark
andmaking cuts on the bark and scraping them.

4.Discuss the effectiveness of root promoting substances/hormones.

Rooting hormone will increase the chance of successful plant rooting in most
cases. When rooting hormones are used, the root will generally develop
quickly and be of higher quality than when plant-rooting hormones are not
used. Applying too much rooting hormone can damage the cutting. Just as
taking too much medicine doesn’t cure you any faster, overdosing on rooting
hormone harms the cutting rather than help sit.

5.Considering the materials you used. Which is more advantageous to use,

hardwood, semi-hardwood or softwood cuttings? Why?

Softwood and herbaceous cuttings are the most likely to develop roots and
become independent plants, hardwood cuttings the least likely.
CONCLUSION

Air layering or marcotting is important and has a lot of advantages in some

plants that produced sexually.Marcottingalso improve the early bearing which
clones are starting to produce much earlier than trees grown of seeds. The
marcotting method can produce the smaller trees such the trees, even fully
grown, stay smaller and so need not as much space in the garden or block
and are easier to harvest. By understanding the methods of layering we can
apply a certain method that is suitable for a particular plant, basically, to
layer plants effectively. Lastly, with the use of root hormones we can improve
our marcots. As such, rooting hormone will increase the chance of successful
plant rooting in most cases. When rooting hormones are used, the root will
generally develop quickly and be of higher quality than when plant-rooting
hormones are not used.

REFERENCES

Bareja, Ben (2021-08-27). “What Is Air Layering, Its Advantages, and

Disadvantages”. Crops Review.New Plants From Layering, Department of
Horticulture, Purdue University Cooperative Extension