PROPAGATION BY LAYERING
I. WHAT IS LAYERING
-A propagation
method by which adventitious roots are induced on a stem
while it is still attached to the parent plant
II. FACTORS AFFECTING THE SUCCESS OF LAYERING
A. Nutrition
B. Stress -use of mist (water stress detrimental)
C. Stem Treatments
-Bending,
cut, notching, girdling
-Interruption
of downward translocation of organic compounds
(carbohydrates, auxin, rooting cofactors)
D. Light Exclusion
-prevent destruction of auxin
-Blanching
----- covering of an intact stem
-Etiolation
----- due to shoot development and elongation in the absence of light
E. Physiological
Conditioning
-Movement
of carbohydrate
-Seasonal
growth style
F. Rejuvenation
-Rooting
at the base of new shoots
III. USES OF LAYERING
A. Multiplication
of plants that reproduce naturally by layering
-Black
raspberries, trailing blackberries
B. Propagation
of plants whose cuttings do not root easily
-Filberts
-Muscadine
grapes
-Mango,
litchi
C. Producing
a large-sized plant quickly
-Ficus
elastica
D. Propagation
of plants without propagation facility
-use of
outdoors, large plants
IV. DISADVANTAGES
A. Labor intensive
B. Not cost efficient
C. Mass propagation
often difficult
V. TYPES OF LAYERING
A. Tip layering
-Use of
succulent branches with tips burried in soil
-Blackberries,
raspberries
B. Simple layering
-One-year-old
shoots
-Flexible
braches are bent down and burried in the middle
-Filberts,
dieffenbachia, many other plants
C. Serpentine
layering
-Similar
to simple layering
-Branch
is covered at multiple sites
-Muscadine
grape, clematis, wisteria
D. Air layering
-Girdle
the bark of a stem at the site desired for root initiation
-Use one-year-old
stem
-Growth
regulator application to wound site, wrap with poly film
and stuff sphagnum peat moss between film and girdle
-Ficus,
monstera, croton, mango, citrus, philodendron, dracaena,
many tropical plants
E. Mound layering
(stooling)
-Cut back
stems in spring to the ground level
-When
new shoots develop, put a soil mound to cover the bases
-Plants
are separated after rooting
-Apple
rootstocks, cashew, pecan, many fruit trees
F. Trench layering
-Bury
a branch longitudinally in a trench
-Shoots
emerge from nodal points
-Difficult-to-root
woody plants