Transcript POWER_AND_TECH_files/Unit 11

PLANT PROPAGATION
The creation of new life!
Propagation means to multiply or make new
Propagation methods require:
Knowledge
Skill
Practice
Propagation is an ART!!
PROPAGATION METHODS
Sexual propagation: Reproduction
involving a female (egg) and
male (pollen) sex cells to produce
a seed
 Some plants can only be reproduced
by seeds
Cross-pollination is when one
flower is pollinated by another
flower with different characteristics
Self-pollination is when pollen of the
same plant is used
PROPAGATION METHODS
 Asexual propagation: Reproduction using cuttings
from leaves, stems, or roots to make new plants
 Based on the principle of totipotency
 Allows the production of a CONSISTENT crop
 Totipotency is the ability of a single cell to divide and
recreate another type of cell
 Creates a monoculture
 Only one plant variety is present
in a particular environment
SEED GERMINATION
 As a seed germinates, or begins to grow, it will start to
absorb water
 After the seed coat cracks, two things happen:
 The radicle, the plant’s first root emerges into the soil to
serve as an anchor
 The plumule, also known as the shoot or seed bud,
emerges from the soil
 Cotyledons, or seed leaves, emerge
 Dicotyledons: plants with two cotyledons – Example: Beans
 Monocotyledons: plants with one codyledon – Example: Corn
GERMINATION CONDITIONS
 The seedbed is the soil or medium in which seeds are sown
 The seed has requirements for:
 Temperature
 Wind tolerance
 Insects and pests
 Moisture
 Exposure to light
 Air circulation
 Planting depth
 Placing between seeds
DORMANCY
Two methods of breaking seed dormancy:
 Scarification: The process of slightly
damaging or breaking the tough seed coat
which allows water penetration into the
seed
 Example: Rubbing seed against sand paper, a
file, or a rough surface
 Stratification: A cold treatment process
given to some seeds to complete ripening
and overcome dormancy
 Seeds are place in a plastic bag
inside a refrigerator around 36-38° F
METHODS OF SEEDING
 When propagating by seed, you must think
of the appropriate method:
 Indirect seeding: Seeds are first
planted in pots or containers
 Direct seeding: Seeds are
planted directly into the garden
 When seeds planted indirectly,
they must be transplanted
 Transplanting: To move a plant
from one location and plant it in another
METHODS OF DIRECT SEEDING
 Furrow method: narrow grooves
are made into the soil
 Broadcasting: sprinkling the seeds
across a given area
 Individual method: placing the
seeds in the soil or media by hand
 Can be done by hand or
automated equipment
 Large commercial operations
 Specialized growing
AFTER SOWING SEEDS
 Make sure to place an identification
marker!!
 Name of seed and date sown
 Lightly mist the media until damp
 In order to retain moisture, plastic wrap
can be applied over the top of the flat
 Make sure to harden-off plants grown
indoors before moving them outside
 Hardening-off: process where young
plants receive less care and a greater
range in temperatures in order to
acclimate them to living outside
TYPES OF AVAILABLE SEEDS
 Seed selection is VERY important
 Seeds are labeled with:
 Name of the plant
 Expiration date
 Germination percentage
 Plant seed percentage
 Inert material percentage
 The germination rate is the
amount of seeds that are expected to germinate
 Inert material may be weed seeds or plant material
ROOT PROMOTION IN ASEXUAL PROPAGATION
 Asexual propagation is like cloning plants
 Having an appropriate rooting medium is
important
 A sterile mix, free of diseases or pests
 Horitcultural sand
 Moss – Peat and sphagnum
 Vermiculite
 Perlite
 Often cuttings are grown in a
mixture of these
ASEXUAL PROPAGATION
 Temperature is important
 Some plants prefer bottom heat which is
artificial heat that keeps the soil or media warm
 Moisture and light exposure are also significant
 Cuttings can be taken from different plant growth
 Softwood: New plant growth
 Hardwood: Older growth
on a woody plant
STOCK PLANT
 To give cuttings the best start,
the stock plant, or main plant
the cuttings are taken from
should be:
 Healthy specimen
 Free of insects and disease
 Take cuttings from the top of
the plant which is often
younger, cleaner, and healthier
 Auxin is sometimes required in asexual propagation for
root development
METHODS OF ASEXUAL PROPAGATION
 Cutting: a process where part of the stock is cut off in
order to reproduce a new plant
 Stem cutting: Requires at least 3 nodes per cutting
 Tip cutting: Cutting from the tip of the stem
 Leaf cutting: a leaf, a leaf and petiole, or a portion
of a leaf is taken from the stock plant
 Polarity: Tendency of a cutting to develop
roots from the bottom and sprouts from
the top
 Leaf-bud cutting: Cutting of a bud and node
 Root cutting: Cuttings from roots
LAYERING
METHODS OF ASEXUAL PROPAGATION
 Division: Process of dividing plant that spread
underground
 Example: Iris, daylily, ferns
 Separation: Process of propagating plants that
spread by aboveground stems or bulblets
 Example: Spider plant
 Tissue Culture: Cloning plants
from genetic material
GRAFTING
 Grafting: Attaching twigs, buds, or
roots onto other stems or roots
The two plants must be closely related
for the plants to fuse
 Scion: Portion of the plant attached
during grafting
 Rootstock: The lower portion of the
plant that receives the graft or bud
 Interstock: A twig that is grafted
between the scion and rootstock
BUDDING METHODS
 Budding: A form of grafting where a
bud is attached to stock plant by
various means to produce a more
desirable plant
 A budstick twig is used as a source
of buds
 Patch method
 Chip bud
 T-bud
OTHER TYPES OF GRAFTING
 Whip and tongue
 Bark graft
 Slipping bark: When the cambium is actively growing
and can be pulled back easily
 Approach
 Four-flap grafting