TECHNIQUES OF PROPAGATION BY CUTTINGS
I. TYPES OF CUTTINGS
1. Stem cuttings
a. hardwood (deciduous, narrow-leaved evergreen)
b. semi-hardwood
c. softwood
d. herbaceous
2. Leaf cuttings
3. Leaf-bud cuttings (single-eye or double-eye nodal)
4. Root cuttings
A. Stem Cuttings
1) Hardwood
cuttings (deciduous)
-easy to prepare and ship, inexpensive "canes"
-most hardwood cuttings are prepared during the dormant season (late fall,
winter, early spring)
i.e. privet, forsythia, wisteria, salix, cornus, spirea
-cuttings taken from the shoots grown in the previous growing season
some cuttings are from 2-year-old woods (fig, olive, plum)
-obtain cuttings from healthy stock plants
nutritional status of cutting wood affects rooting
-cut just below a node and 1.3-2.5 cm (.5-1 in) above a top node
cutting length varies with species
'De eyeing' needed for rose (Rosa muliflora) planted in the field
use of a slanted cut to identify a proximal or distal end
2. Narrow-leaved
evergreens
-slow rooting: moisture condition important
-ease of rooting
easy to root --- low-growing junipers, Thuja, chamaecyparis, Taxus
difficult to root- upright junipers, spruce, hemlock (Tsuga) pinus,
firs (Abies)
-cuttings are taken between late fall to late winter
-cutting types
most cuttings --------- straight cuttings (new growth)
Juniperus chinensis --- old, heavier wood good
Juniperus excelsa ---- older shoots harvested from lower
part of stock plant better
Taxus species -------- heel or mallet cuttings better
3. Semi
hardwood cuttings
-summer or early fall cuttings
somewhere between succulent and woody stem
-spring softwood cuttings prepared in heel or mallets
own root peach cuttings (1000 ppm IBA teatment)
-species
camellia, pittosporum, rhododendron, azalea, holly, eunymus
4. Softwood
cuttings
-spring or summer cuttings of soft, succulent growth
-generally root fast
-swift handling important to prevent dehydration
-species
(forsythia, magnolia, weigela, spirea, pyracantha, oleander, hydrangea, poinsettia)
5. Herbaceous
cuttings
-cuttings of succulent, herbaceous plants
-fast rooting
-growth regulator treatment may not be needed
-presence of leaf enhances rooting
-species
geraniums, chrysanthemum, coleus, carnation, many foliage plants (tropical
plants)
B. Leaf Cuttings
-Adventitious
roots and shoots formed at the base of leaf blade, leaf petiole
-The original
leaf does not become part of the new plant
-Examples
Sansevieria ---- new plant forms at the base
S. trifasciata laurenti -varigated sansevieria
periclinal chimera- use a division method
Begonia rex ---- leaf sections containing vein
African violet ---leaf with petiole
Kalanchoe pinnata (Bryophyllum pinnata) - offsets
C. Leaf-bud Cuttings
-Consists
of a leaf blade, petiole, an axillary bud on a node
-Single-eye
or double-eye nodal cuttings
-Examples
D. Root Cuttings
-Roots
of young stock plants (juvenile)
-Taken
during winter and early spring
before new growth starts
carbohydrates stored in root essential
-Stick
root cuttings with the proximal end upward
-Plants
that can be propagated by root cuttings
coralberry (Acantopanax pentaphyllus)
trumpet vine (Campsis ranicans)
flowering quince (Chaenomeles speciosa)
bleeding heart (Dicentra species)
fig (Ficus carica)
apple (Malus species)
phlox (Phlox species)
white poplar ( Populus alba)
sumac (Rhus spp.)
black locust (Robinia pseudoacacia)
rose (Rosa spp.)
sassafras (Sassafras albidum)
lilac (Syringa vugaris)
II. STOCK PLANT MANIPULAITON
A. Pruning and Girdling
-Pruning
annually needed
maintain juvenility, plant shaping, increased cutting production
timing for flushes, reduce reproductive shoots
-Type
of pruning
a.stooling- Hydrangea, Senecio
b.hard pruning- Forysythia, Weigela
c.light pruning- only tips removed
d.moderate pruning- Viburnum
e.hedging- berberies, Pyracantha
f.renewal pruning- 3year schedule
g.double pruning
-Girdling
to induce root primordia (IBA helpful)
pines, sweetgum, sycamore, oak
exclusion of light at root initiation site
B. Etiolation, Shading, Banding
-Used
for difficult-to-root plants
-Cuttings
are taken after a series of events involving shading, banding, and blanching
followed by growth regulator treatment
III. ROOTING MEDIA
- Aeration, water retension important
- Coarse mineral
materials
perlite, vermiculite, scoria, pumice, rockwool, sand
sterile materials
- Organic amendments
also used
peat-lite, peat-rockwool (peatwool)
peat-vermiculite, peat-bark-sand
- Nutrients
during rooting not essential
fertilizer is needed after root initiation
- Propagation
unit systems (commercial)
Jiffy-7 used for herbaceous
Root cubes
Rockwool blocks
Gro-plugs
- Some plants
can be direct stuck
i.e. Geranium, poinsettia, chrysanthemums
IV. WOUNDING
-Wounding at
the base of the cutting promotes rooting in some species
i.e. Juniper,
arborvitae, rhododendron, maple, holly, magnolia
-Stripping the
basal leaves off a cutting
i.e. Juniper,
berberry
-Use of razor
blade or wounding tool
V. GROWTH REGULATOR TREATMENTS
-Auxin-type growth regulators (IAA, IBA, NAA)
Increase percent cuttings rooting
Hasten root initiation
Increase number of roots per cutting
Enhance uniformity and quality of rooting
A. Growth Regulators
-Indolebutyric
Acid (IBA) most commonly used
-Naphthaleneacetic
acid (NAA) used less frequently
-IBA or
NAA is prepared in the liquid or powder form
K-salt form of IBA now available (Organic chemistry)
-water soluble
-just dissolve 2g K-IBA in 1000ml water
to get a 2,000 ppm solution
B. Methods of
Growth Regulator Applications
1. Using
commercial powder preparations
-wood or difficult-to-root plants need higher strengths
-herbaceous (easy-to-root) cuttings need low strengths
-treat a bundle of freshly cut cuttings together
-pretreatment with 50% ETOH, methanol, or Aceton may be used
-Immediately stick after treatment
2. Quick-Dip
method
-use 500ppm-10,000 ppm IBA solution
-dip 1 cm at the proximal ends for approx. 5 seconds or more
-immediatly stick in soil
-use small alliquot of solution each time
3. Soaking
(old method)
-soak the cut ends (2.5 cm of proximal end) in a dilute IBA solution (~100
ppm) over night
-may be used for difficult-to-root plants
4. 'Toothpick'
method
-used for difficult-to-root plants (i.e.oak)
-insert a toothpick that has been pretreated in a solution of high concentration
IBA into the cutting
VI. DISEASE PREVENTION
- Harvest cuttings
from disease-free stock plants
- Surface disinfestation
use disinfectants
physon
chlorine dioxide (ClO2)
isopropyl alcohol
monochloramine
sodium hypochloride (clorox)
- Fungicide treatment
use of
fungicide solution to dip cuttings
Benlate, Captan, alliette (systemic)
- Fungicide drenches
during propagation
"Banrot"-
pythium, rhizoc
- Rose crown gall
control
use of non-virulent
form of Agrobacterium
- Mycorrhizal
fungi may be added to the rooting media
difficulty in incorporating
beneficial endomycorrhize
VII. ENVIRONMENTAL CONTROL
A. Enclosed
Structures
-Polyethylene
tunnels
-Coldframes
or Hotframes (bottom heat recommended)
-Indoor
polytents (Wardian Case)
B. Intermittent
Misting
-Widely
used for softwood, semihardwood, hardwood, herbaceous cuttings
-Open
mist (outdoor) vs. enclosed mist (indoor)
-Intervals
and duration vary by environmental conditions
15sec/30min intervals, etc.
C. Mist Nozzles
-Influence
droplet sizes (50-100 µm)
-Types
of nozzles
pressure jet
whirl nozzle
deflection (anvil nozzle)
D. Types of
Mist Controls
-Timers-----1)
24-hour time clock
2) on/off controller (interval vs. duration)
-Electronic
leaf
-Screen
balance
-Photoelectric
cell
-Comperterized
controll
E. Fogging
Systems
-Droplet
size <20 µm (stainless pipe, pure water)
-Centripetal
foggers (oscillating)
-High
pressure fogging (MEE system, micromist)
(500-1000 psi)
VIII. SANITATION
A. Algal Growth
Contol
Blue-green
algae (Oscillatoria, phormidium, arthrospira)
Green
algae (stichococcus, chlamydomonas)
-control
eliminate water collection areas
algicides- Algimine, Algae-Go 36-20
Algofen (dicklorophen), Cyprex
Agribrome (bromine)
B. Water Quality
pH
soluble
salts
total
carbonates
SAR ----Sodium
absorption ratio
IX. CUTTING NUTRITION
- Nutrients
in leaf tissues are leached out during misting
start
out with healthy cuttings
- Root initiation
does not require exogeous fertilizer
- Fertilizers
are needed after root formation
- If fertilizer
is needed (i.e. ligustrum) use slow release fertilizers
in rooting medium (Osmocote)