Herbaceous Cuttings - NAAE Communities of Practice

advertisement
Herbaceous Cuttings
Plant Science

Which of the following plants do you
think would be easier to propagate using
the leaves?
Plant Propagation by Cuttings

Asexual propagation - the controlled reproduction
of plants by taking a piece of vegetative plant
tissue and encouraging it to regenerate a
complete plant.

Sexual propagation - development of a new plant
by meiosis & fertilization in the flower to produce
a viable embryo in a seed.

Totipotency – ability of a single cell to regenerate
all characteristics of the plant.
Advantages of asexual
propagation






Plants are uniform
Quick establishment
Only means of propagation in certain
species
Seed-borne diseases avoided
Less expensive
Heterozygous material may be
propagated without genetic alteration
Disadvantages of asexual
propagation





Systemic viral infection can spread to all
plants
Planting materials are bulky
Storage of asexual material is cumbersome
and short term
All plants are genetically identical and
subject to the same hazards to the same
degree
Mechanical propagation in some cases is
not practical
4 Categories of Cuttings

Softwood cuttings – from soft, succulent, new spring growth
of deciduous or evergreen species

Semi-hardwood cuttings – from woody, broad leaved
evergreens, and leafy summer cuttings of deciduous
plants with partially matured wood

Hardwood cuttings – from dormant woody material –
taken in late winter or early spring before leaves appear –
from previous year’s growth

Herbaceous cuttings – from succulent, non-woody plants,
with leaves at upper end
Types of Herbaceous Cuttings





Definition of a cutting -Detached
vegetative material from a plant used
to produce a new plant.
4 types:
Stem
Leaf
Leaf-bud
Root
Stem Cuttings
2 types
 Stem-tip cuttings – tip (terminal end) is
cut and used to produce a seedling
 Stem-section cuttings – pieces of stems
containing at least one bud (not a
terminal bud) and used to produce a
seedling

Leaf cuttings
A whole leaf or part of one that is
detached and used to raise a new plant.
 Examples: begonia, peperomia, African
violet
 Cutting consists of leaf plus part of the
leaf stalk (petiole)
 Leaf-vein cuttings –
 cutting the veins at several points and
securing the leaf on the media

Leaf-bud cuttings
Consists of a short piece of a leaf,
petiole, and short piece of stem with an
attached bud in the leaf axil.
 Great when source material is scarce.

Root cuttings
Small sections of the roots are divided and
planted vertically or horizontally.
Proximal – nearest the crown of the plant –
always should be up
Distal – farthest from the crown
Cuttings and Water uptake

Removed from functioning root system

There is little to no water uptake and can
lose water to the air

Placing cuttings under a intermittent mist
system provides water and high humidity
Adventitious roots

New roots form in places that normally
do not grow roots (Ex: Stems, leaves)
Cultural requirements

The tissue of the cuttings should contain enough
of the organic and inorganic nutrients to support
new growth to the point of becoming selfsupporting.
- Electric heating cables are commonly used to
hold the medium at about 75F. Air temperature
of 70-80F day and 60-70F night are generally
satisfactory.
Light Requirements

The presence or absence of light is generally not
decisive in rooting, although light tends to inhibit
root initiation.

The general practice is to use shading to decrease
light intensity but not to exclude light.
Media

The rooting medium should be well aerated, hold
sufficient moisture, and be easily sanitized.

Soil is generally a poor choice. Commonly used
media include perlite, and various mixtures of
sand, peat, and vermiculite.

In this lab we will use a 1:3, Bark Mix :Perlite mix
Auxins
Auxins - a group of natural plant growth
hormones, which can be applied directly to the
cuttings.
 Most commonly used compounds: synthetic
auxins,
indolebutyric
acid (IBA), and
napthaleneacetic acid (NAA).
 Available in powder and liquid forms
 Rootone, Hormodin, Rhizapon & Dip ‘N Grow.

Common Auxins

Indole 3- butyric acid (IBA)
- Best for general use, non-toxic to plants over a
wide concentration range

Napthaleneacetic acid (NAA)
Powder Formulations Vs Liquid
Formulations of Rooting Hormones
Is Dip’ N Gro the Way to Go?
Liquid rooting hormone vs. powder
formulations
 Contains both IBA and NAA
 Dilution rates – versatility of product
 Absorbance into cutting vascular system
 Alcohol incorporated into product –
sanitation
 Superior Performance

Auxin Forms

Powder – Rhizapon, Hormodin, etc.
› Easy to use, but not as uniform
› Not as effective as liquid auxins Predrilling holes for sticking

Liquid - Dip ‘n Grow
› Usually 3 to 5 second dip in solution
› Dip as a bundle, not one by one
› Majority of auxin is absorbed at the cut
surface of cutting base
› Versatile

Depending of plant material,
concentration levels are suggested:
› Herbaceous & Softwood 1:20
› Semi-hardwood 1:10
› Hardwood 1:5

Dip time: 3-5 seconds
› 5-second dip is equally effective as a 160-
second dip in promoting root growth. Longer
dips, may cause phytotoxicity
Problem with auxins – they degrade in
light
 Powder formulations – once opened,
subject to clumping
 Liquid – 3 year shelf life if kept in a sealed
container
 Once diluted, 10 hour effectiveness

Another Issue: Auxins in Excess

Inhibit bud development

Cause yellowing and dropping of leaves

Blackening of the stem

Eventual death of cutting
Which should a grower use?
Other Methods of Application
Spray auxins to runoff over base of
cutting
 Cuttings stuck in media and auxin
sprayed on leaves and stem until auxin
drips in to media
 Total immersion of cuttings - ivy, clematis,
Ficus

Pre-Chemical Treatment of
Cuttings

Treated with broad spectrum fungicidal
dips prior to sticking
Sources for plant materials:
Outdoor landscape
 Greenhouse
 Annuals
 Houseplants
 Friends and Neighbors

Lab: Herbaceous Cuttings
- In addition to the different concentration levels,
the length of time that the growth regulator
remains in contact with the base of the cutting
can also have an effect on rooting, which will be
demonstrated in this laboratory project.
Materials Needed








Plant cuttings (to be designated)
Propagation knife or razor blade
Labels
Pencil
1000 ppm IBA (Indole-3-butyric acid) and
500 ppm NAA (1-Naphthaleneacetic acid)
Dip’ N Grow Dilution cup
Propagation medium in flats1:3 Bark Mix : Perlite
Herbaceous Cuttings: Methods
Each group should prepare 12 uniform stem cuttings from the same
genus, species and if applicable the same cultivar or variety and divide
them into 4 equal groups.
Re-cut the base of each group of cuttings and dip the base of each
group into 1000 ppm IBA 500 ppm NAA (1:19 Dip N’ Grow : water)
for the following time periods:
0 second- control
 2 seconds
 15 seconds
 30 seconds

Any Questions??
Download