Plant Propagation PPT

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Transcript Plant Propagation PPT

Objective 17.1
Define Propagation.
 Objective 17.2
List the two types of plant propagation.
 Objective 17.3
Define germination.
 Objective 17.4
Identify the life cycle of plants.
 Objective 17.5
Identify the parts of a seed.
 Objective
Define seed dormancy.
 Objective 17.7
Explain why some seeds will not
germinate right after ripening.
 Objective 17.8
Define scarification.
 Objective 17.9
Identify the factors affecting germination.
 Objective
Identify germination media
requirements and components.
 Objective 17.11
Explain the ideal germination
 Objective 17.12
Identify the proper steps in
transplanting a seedling.
Define Propagation
Propagation: the
increase of a plant
species from one
generation to the
List the two types of plant
Sexual propagation:
– The union of a male
and female gamete.
– Produces a
genetically unique
Asexual propagation:
– The “clone” of a
plant that is
genetically identical
to the “mother
Define germination
Germination: the
development of a
seed from a resting
stage to a stage of
Stages of Germination
Identify the life cycle of plants
–Germinate, grow, flower and
die in one growing season.
 Seed Coat:
– Hard surface that protects
the interior of a plant.
Comprised of two coats
–Testa: outer layer
 Endosperm/Cotyledons:
– Food storage section of
the seed.
It supplies enough
energy for the plant to
grow until the leaves
start to produce
– The miniature plant that forms from the
union of the sex gametes.
Four parts
1st terminal bud
Develops into the first shoot that
emerges from the seed.
true stem
– Causes the
plumule and
cotyledons to
emerge from
the seed.
root of the
1st to emerge
from the seed
1st leaf or
leaves that
emerge from
the seed.
They fall off
after the 1st
true leaves
Define seed dormancy
 Seed
–A protective condition that prevents
the seed from germinating until all of
the environmental factors required
for optimum growth are present.
Explain why some seeds will not
germinate right after ripening
 Some
seed coats are too thick or
extremely hard to allow moisture
into the embryo.
 Some seed coats contain a
chemical inhibitor that must be
washed away.
Define Scarification & stratification
 Scarification:
– The scratching or removal of the seed
coat to induce germination.
 Sandpaper
 Removal
of an end of the seed
 Create a crack in the seed
 Soak in sulfuric acid
– Must be washed several times after soaking in
sulfuric acid.
– dried
Identify the factors affecting
 Water
– The seed does not need to be submerged
in water, just moist.
– The water softens the seed coat.
– Causes the embryo to release the
hormone gibberlin.
– Gibberlin activates digestive enzymes
that cause the release of cytokins &
– Cytokins and auxins induce cell
elongation and cell division.
 Temperature
– Minimum: point at which seed will NOT
 32-39
– Optimum: desired level for most species
 68-86
– Maximum: point at which seeds will not
 113-120
 Light
– Affects germination
– 4 types of light
responsive plants
 Full
 Half light/ half dark
 Full darkness
 No affect either way
Identify germination media
requirements and components
 Requirements
– Not too heavy
– Contain small amount
of nutrients for plant growth
– Free of all pathogens or weeds
– Holds water, but allows aeration and
drainage (porosity) components
 Vermiculite
–Soft surface
–Light weight
–Holds 500 % water by weight
(1ft3=9lbs=40 lbs of water)
 Perlite
– Sterile
– Volcanic rock
– Light weight
– Rough surface holds water because of
surface tension
– Drains well
– pH 7.0-7.5
– Dusty & floats out of the medium
Ideal general propagation soil
Two bushels
Sphagnum peat moss- 1 bushel
Horticulture vermiculite 3- 1 bushel
Ground limestone- 10 tablespoons
20% supers phosphate- 5 tablespoons
Ammonium nitrate- 4 tablespoons
Chelated iron sequestrene 300- 1 level
* marithon= systemic insecticide
Explain the ideal germination
 Aeration
– Must have enough air for respiration
– If the soil is too hard (no pore space),
water retention will be dramatically
 Temperature
–Plants have an optimum
temperature for growth
–Bottom heat (5-10 higher than the
air temperature) helps expedite
–Heat should be removed once
germination occurs because the
plants become too succulent (soft)
and “leggy” and does not
transplant well.
 Moisture
–Too much water causes the plant to
–Too light water causes the plant to dry
out and die.
Water drives many of the reactions
in the plant.
–Photosynthesis, respiration,
nutrient uptake and nutrient
 Intermittent
Low-Pressure Misting
– Controlled by a
 Time clock
 Solar-activated counter
 Electronic leaf
 Sub irrigation
– Seed flats are soaked with water from
the bottom.
* Applied only during daylight hours because of
disease and lower temperature caused by
evaporative cooling of the water
 Light
– Red wavelengths have the most
influence on germination
– Far-red light become “leggy”
Identify the proper steps in
transplanting a seedling
Transplant once the 1st
true leaves are fully
Only remove plant
from the plug-tray
that can be planted
within a few minutes
Water once
transplanted to set the
soil and prevent
drying out