Vegetative Propagation

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Vegetative Propagation

• Development of plants from
• Stem Cuttings

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Introduction

• Cuttings can be taken from almost any part of the
  stock plant (the original plant) to produce new
  plants that are genetically identical.
• The actual method chosen depends on the species
  of plant and time of year
• Stem
• Softwood
• Herbaceous
• Semi hardwood (evergreen)
• Deciduous hardwood
• Leaf
• Roots

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Steps in taking Softwood cuttings

• Softwood cuttings are taken from the tips of
  shoots which are young and green and where the
  stem is still soft.
• The cutting should be 5 10 cm long
• The lower leaves should be removed to reduce lose
  of water through transpiration sometimes it is
  also necessary to reduce the area of larger
  leaves as well.
• The cut end should be dipped into a rooting
  hormone (Seradix B no.1, containing IBA
  indole-3-butyric acid)
• The cutting should then be inserted into a
  rooting medium and left in a humid environment.

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Steps in taking Herbaceous Cuttings

• Succulent, nonwoody plants (Chrysanthemums,
  Carnations etc.) may be propagated this way
• A stem 8 13 cm long with or without leaves
• The conditions required for sucessful propagation
  are the same as for softwood cuttings
• Bottom Heat (placing the pot on a heating pad to
  warm the rooting medium up to an optimum 20 25
  oC) will stimulate root formation to be initiated
  faster.

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Steps in taking Semihardwood Cuttings

• Woody, broadleaved evergreen plants are
  propagated in this way
• The stem should be 8 15 cm long with lower
  leaves removed (up to a 1/3 of the original
  surface area)
• The stem should be removed just below a bud
• A heel should be left on the cutting to increase
  the surface area of the cambium cells (growing
  and dividing cells). This can be done by pulling
  the stem downwards to rip a little of the bark
  off the stock plant
• IBA, high humidity and bottom heat enhance rooting

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Steps in taking Deciduous Cuttings

• This method is suitable for deciduous or
  narrow-leaved evergreen species such as pines)
• The length of the stem varies depending on the
  species e.g. 20 cm for black currants to 3 m for
  poplar poles
• At least 2 buds (nodes) must be on the stem
• The material is usually taken from last seasons
  growth during autumn (pruned branches are often
  used)
• The stem may be wounded by removing bark from the
  just above the basal cutting (at the bottom) to
  expose more cambium aids root development
• Dipping in a strong IBA powder such as Seradix 3
  is often required
• The stems should be inserted into the ground
  outside and do not require any additional heat or
  increased humidity because they do not have any
  leaves to lose water from

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Summary of Stem Cuttings
Type of cutting Description Season propagated Length of cutting Conditions
Softwood New, soft succulent woody species Spring to summer 8 13 cm High humidity, bottom heat, rooting hormone (Auxin such as IBA)
Herbaceous Succulent stems from nonwoody plants Year round 8 13 cm High humidity, bottom heat
Semi-hardwood Partially mature wood on current seasons growth, wood plants Late spring to late summer 8 15 cm IBA, high humidity and bottom heat. Cutting should be wounded to have a heel
Deciduous Mature, dormant, woody plants Autumn to late winter Up to 3 m A high concentrated IBA application, planted directly outside
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Steps in taking Root Cuttings

• This method is best carried out on young stock
  plants during winter
• It is not a common method but can be used for
  Wisteria or Ailanthus
• The polarity (which way is up) is very important
  when planting vertically. Usually the root
  cutting is planted horizontally just below the
  surface of the rooting medium
• Bottom heat helps to develop roots and shoots in
  a few weeks

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Leaf Cuttings 1

• The laminar (leaf blade) or petiole (stalk) may
  be used to propagate a few varieties of plants
• African violets and begonias are propagated by
  removing a single leaf (either the whole leaf or
  part of the blade)
• Sansevieria (mother-in-laws tongue) leaves may
  be sliced into sections
• Begonia rex leaves have their veins cut and laid
  flat on the growing medium

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Leaf Cuttings 2

• As the leaves have no roots, they must be
  provided with a highly humid environment and
  bottom heat is recommended
• The new plants develop from either the end of the
  petiole or from the veins of the blade depending
  on the method used

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Physiology of Root and Shoot Formation for
Cuttings

• All cuttings go through similar physiological
  developmental stages from the time of cutting to
  weaning (when the cutting is removed from the
  propagation area to an environment similar to
  which it will be planted).
• Dedifferentiation is the early stage when
  adventitious roots or buds form from
  differentiated cells triggered to form new
  meristematic cells.

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The First StageDedifferentiation this is when
adventitious roots or buds form from
differentiated cells triggered to form new
meristematic cells.This occurs in the cambium
cells.

• The Second Stage
• The formation of root initials from cells near
  the vascular bundles which have become
  meristematic by dedifferentiation.

The Third StageParenchyma cells form callus
which develops behind the wounded surface of
thecutting to protect it from drying out and from
pathogens.
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• The Fourth Stage
• Development of the Root Primordia from the root
  initials.

The Fifth Stage Growth and emergence of the
adventitious roots through the outer tissues and
through the callus. Vascular tissue develops
between the root primordia and the cutting.
The Sixth Stage The cutting is removed from the
propagating area and hardened off or weaned.
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