Transcript GERMINATION - Nc State University

Seeding and Establishment
Germination

1. The seed
a.
sandwiched between lemma and
palea (modified leaves)
b. Caryopsis - dried fruit - has seed
coat with aleurone layer
c.
Endosperm - feeds embryo
d. Embryo
Parts of the Embryo
Apical meristem and immature leaves develops into shoot
 Root primordia plus root cap - develops into
seminal root
 Coleoptile - protects emerging shoot
 Coleorhiza - protects emerging root
 Scutellum - involved in getting
carbohydrates from endosperm, via the
enzyme alpha-amylase


2. The Germination Process
a.
Water is imbibed
1. Seed coat dormancy
2. Irreversible
b. Enzymes activated
1. Hormones released by
scutellum
2. Enzymes needed to
breakdown starch are located
in the aleurone layer
CH2O’s transported to
embryo by scutellum
4. The larger the endosperm the
healthier the seed
Coleorhiza swells and anchors
seed
Primary root (radicle) pushes
through coleorhiza
1. Seminal root
Coleoptile (sheath) reaches surface
and plumule emerges
3.
c.
d.
e.
f.
Mesocotyl elongates in some
seedlings
1. Help protect seed planted
deep if reserves OK
2. Adventitious roots
emerge from crown
3. Plant is able to manufacture
own food after emergence of
first leaf

3. Germination Requirements
a.
Live, non-dormant seed
1. Store in cool, dry place
2. Species differ in germination
b. Adequate moisture
1. Non-reversible process
2. Mulching
3. Light, frequent irrigation
4. Pre-germinated seed
5. Throwing seed on the ground
c.
Proper temperature
1. Some need alternating
temperatures
2. Prechilling of seed Ex. Ky
bluegrass
3. Warm - 70-95; Cool - 60-85
Ex. Species Opt. Soil Temp (Fo)
Bent
59 - 86
Ky-Blue
59 - 77
Tall Fescue
68 - 86
Warm Season
68 - 95
d.
e.
Oxygen
1. Needed for respiration
2. Water logged soils
Light
1. Not always required
2. Crabgrass, goosegrass need
high light
3. Bury too deep in soil

4. Causes of Failure
a.
Plant too deep
b. Crusted soil surface
1. Frequent water
2. Mulch
3. Mechanical breaking
c.
Damage by fertilizer or pesticide
d. Dormancy
e.
Lack of water
5. Initial size of young plant directly related
to seed size
a.
Amount of CH2O reserves
 6. Manage desirable species to out compete
undesirables (weeds)
a.
Cut at height to keep light from soil
surface
b. Fertilize, etc., to keep stand thick
c.
Aerate, water, traffic so not to
compact soil
d. Firm seedbed, proper planting
depth, care during early establishment

Turf Establishment
I. Turf Selection
Selection should be based on the following
criterion:
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Soil Type
Light conditions
Geographic Location
Micro Climates on Site
Desired or Expected Maintenance Level
Knowledge of the many turf species and their
requirements for growth
II. Site Preparation
(1) Soil Samples should be submitted 4-5
weeks before turf installation
(2) Site should be Cleared of all rocks ,
trash and unwanted vegetation .
(3) Preplant weed control may be obtained
with nonselective herbicides and soil
fumigants .
(4) Grading of the site involves two steps
rough grading and final grading.
(5) Rough grading involves major earth
moving major draining correction
(6) After Rough grading has occurred major
soil modification should take place and
may involve the addition of lime,
fertilizers, organic amendments and new
soil.
(7) Once all rough grading has taken place,
the installation of drainage lines and
irrigation systems should begin.
(8) Final grading may be accomplished by
several methods including:
hand raking,
drag mats, and
cultipacker/landscape blades .
(9) Before the planting of any grass proper
starter fertilizer should be applied to
the site, and should be based on the
soil test .
III. Turfgrass Planting
The four main types of turf
establishment are:
seeding,
sprigging,
plugging
plugging
After all site preparations have been
completed establishment may begin.

Seeding.
– Correct methods of spreading seeds
include: rotary spreader, drop spreader
hydroseeder
– All methods of spreading seed must be
calibrated so that they will apply the seeds at
the correct rate and uniform in distribution.
– After seeds are spread they should be mulched
with straw/hay to help maintain soil moisture
– Types of Mulches in use today include: straw
(wheat), pine straw fiber mats/cloths, shredded
newspaper
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Sprigging
(1)
(2)
(3)
(4)
What are sprigs? individual plants or
sections of grass plants which contain
several viable nodes, usually stolons
Grasses which may be sprigged are:
bermuda’s, zoysia, St. Augustine,
Bentgrass
Sprigs may be spread and planted by:
hand placement (individual),
Broadcast/mechanical
Equipment which may be used to
spread sprigs include: hand placement,
sprig planters , hydro seeder.
(5)
(6)
To help insure sprig establishment,
the sprigs should be rolled/packed to
insure good soil contact, manual
packing, rollers and cultipackers
may be used to pack the sprigs into
the soil.
After the sprigs have been planted
the should be watered 3-5 times
per day for the first 2 weeks after
planting.
(7)
(8)
A light application of mulch (straw)
may be applied to the sprigs to help
maintain adequate soil moisture.
Fertilizing the sprigs will depend on
the type of grass and the desired rate
of establishment. In general you
should apply balanced fertilizer at the
time of sprigging and 1/2 lb N/1000
sq ft very two weeks for a month after
sprig planting.

Plugs
(1)
(2)
(3)
What are plugs? small sections of
turf which include roots.
Grasses which may be plugged
include: All grasses which spread
by stolons and or Rhizomes.
Sources of plugs are:
individually grown plugs, sod cut
up, aeration cores.
(4)
(5)
Plugs may be planted by hand
and by specialized machine.
The watering schedule for plugs is
basically the same as for
sprigging.

Sod
(1)
(2)
(3)
(4)
What is Sod?
large sections of intact turf
Which grasses may be planted as
sod? all grasses
Sod is planted by laying the sections
in a uniform manner without cracks
between sections to provide a
complete covering of the soil.
After the sod is laid it must be
rolled to insure there is good root to
soil contact.
(5)
(6)
If after laying the sod cracks
are still present they should be
filled with sand/soil to reduce
desiccation of the sod edges.
In some cases the sod may be
topdressed with sand to reduce
undulations on the turf. This
practice of topdressing is mainly
used in the golf course industry for
newly sodded tees and greens.
(7) After installation, sod should be
watered as follows: lightly 3-5
times/day to maintain adequate soil
moisture for minimum of 2 weeks after
planting

Post Planting Care
(1) Mowing:
Seeded sites
Sprigs/Plugs
Sod
(2) Fertilization:
Seeded sites
Sprigs/Plugs
Sod
(3)
Pest Management:
Weeds in newly established lawns.
Insects in newly established lawns.
Diseases of newly seeded lawns.

IV. Lawn Renovation
1. What is renovation? Establishment
of new or different turf into or on an
existing site without major soil
disturbance
(1) There are two types of renovation
complete and partial.
(2) Partial Renovation involves the
establishment of a new turf in an
existing lawn without killing the
existing lawn.
(3)
Benefits of partial renovation
include reduced erosion and
better control of soil moisture by
using the old lawn as a nurse
grass.
(4) Problems which may result from
partial renovation are lack of
control of problem weeds and
possible competition from the old
turf.
(5)
(6)
Complete renovation involves the
killing/removal of the existing
turf without major soil
disturbance.
Benefits from complete renovation
are complete control of problem
weeds and existing turf, which
result in less competition for the
new turf.
(7)
(8)
Complete renovation sites may
suffer from erosion and poor water
retention due to the removal of all
organic matter/vegetative material
from the site.
The three ways to establish turf
during a partial renovation are:
overseeding, slit seeding and
plugging/sprigging.
(9)
The procedure for partial
renovation is:
a.
mow old lawn short and
remove clippings.
b. use selective herbicides or
spot sprig nonselective
herbicides to control
problem weeds
c.
verticut or aerate
d. seed, slit seed, plug
Slit Seeder
Seed Box
Seed Delivery
(10) The procedure for complete
renovation is:
a.
use nonselective herbicide
to kill lawn and weeds
b. wait recommended time
before planting
c.
mow site low after kill and
remove clippings
d. verticut heavily or aerate
site
e.
remove debris and or drag
in cores
f.
seed, slit seed, plug
(11) Post planting care for a renovated
site is basically the same as
normal establishment procedures.