Tree propagation and maintance Flashcards
1
Q
Sexual reproduction
A
- Sexual reproduction
- Genetic recombination from 1 or more
parent trees - Unpredictable outcome
2
Q
Asexual Reproduction
A
- Asexual reproduction
- Same genetic material as parent tree
- Predictable outcome
3
Q
Propagation
A
- Producing new trees from the seeds
or vegetative tissue of parent trees - Sexual propagation
- Seeds
- Asexual propagation
- Cuttings, rhizome, stolons, adventitious
buds, suckering, tissue culture
4
Q
Natural vs managed propagation
A
- Natural – Seeds or vegetative tissue produce new trees in
nature - Excludes human intervention
- e.g., natural regeneration
- Managed – Seeds or vegetative tissue produce new trees under
managed conditions - Includes human intervention
- e.g., clonal propagation for plantation forestry
- Used for amenity/urban, horticulture, plantation forestry
5
Q
Sexual propagation
A
- Seed fall (natural) or seed collection (managed)
- Germination (natural or managed)
- When conditions are right
6
Q
Cost of sexual reproduction
A
- Flowering and fruiting is costly, so environmental resilience is
necessary (reason for reproduction beginning in mature state) - If photosynthetic yield is poor only vegetative buds, no
reproductive buds for next year
7
Q
Sexual propagaiton (stratification)
A
- Period of cold (and possibly moisture)
followed by warmer conditions - Achieved under natural conditions by
transition from winter into spring - Buried or in contact with soil
- Achieved under managed conditions
by temporary cold storage - In a medium of e.g., sand, sawdust, peat
- Breaks embryonic dormancy
- Germination follows
8
Q
Sexual propagation (scarification)
A
- Seed coat can be impermeable to
water and gas → helps to delay
germination - Seed coat needs to be broken down to
allow germination: - Mechanical (e.g., freezing)
- Thermal (e.g., fire)
- Chemical (e.g., digestion)
9
Q
Asexual reproduction features
A
- Vegetative or asexual reproduction
- No need for flowers, cones, fruits, and
seeds - Natural
- Rhizomes, stolons, adventitious buds, suckering
- Managed
- Cuttings, grafting, layering, tissue culture
- All will produce genetically identical
offspring from the parent plant without
need for seed
10
Q
Layering
A
- Roots grow from tree tissue that was
previously above ground - Tissue in contact with ground can be
intentionally wounded to promote
adventitious tissue growth → turns into roots - New tree continues to be supplied with water,
nutrients and photosynthates from parent
tree - Eventually above-ground tissue decomposes,
new tree separates from parent tree
10
Q
Grafting
A
- Tissue from one tree (scion) is
attached to another tree (root
stock) - Vascular tissues repair themselves and
bind together - Ability to optimise both the scion
and root stock for desirable
attributes
10
Q
Maximising success rate of propagation
A
- Success of propagation is called ‘taking’ or
‘striking’ - Striking for layering and cuttings can be
improved by: - Rooting hormone
- Auxin-based powder or liquid that promotes root
growth - Maintaining moist soil environment
- Maintaining humid air
- Success depends primarily on water balance
10
Q
What does a nursery do?
A
- Nursery produces trees for transplanting out into the
landscape - Bare root, ball and burlap, or container-grown trees
10
Q
Cutting
A
- Plant tissue removed from parent plant and
partially buried in rooting media - part of the shoot or root
- 5 – 15 cm for soft wood and 20 – 25 cm for hard
wood - Small hardwood cuttings (~30 cm) called wands
- Large hardwood cuttings (> 1 m) called poles
(poplar/willow) – above forage line - Cutting develops new roots and shoots - same
genetic material as parent plant
11
Q
Bare root tree features
A
- Field grown
- Undercutting and wrenching
produces dense, fibrous root
system → hardens tree against
eventual transplant
12
Q
Ball and burlap tree features
A
- Field grown
- Undercutting and wrenching
produces dense, fibrous root system
→ hardens tree against eventual
transplant - Large root ball, covered by soil, dug
and wrapped in burlap and wire
basket
13
Q
Container-grown tree features
A
- Containers vary in volume and structure
- Soft-walled fabric or plastic planting bags
- Not reusable
- Hard-walled plastic pots
Causes root defects although root pruning pots can mitage this
14
Q
Tree end use
A
- Production size depends on end use
- Plantation forestry, small size (< 30 cm in height)
- Bare root or container
- Amenity/urban, large size (> 200 cm in height)
- Bare root, container, or B&B
- Restoration, small size (< 30 cm in height)
- Bare root or container
- For commercial horticulture, grafting is most common → skipping juvenile stage
15
Q
Root biomass
A
- Implications for posttransplant survival
- Root biomass retained by
containers - Root biomass may be
removed at time of planting
to correct defects - Undercutting, wrenching
and/or tree spade removes
large proportion of roots
from bare root and ball &
burlap trees, but produces
a fibrous root system
16
Q
Root defects
Implications
A
- Implications for post-transplant
survival - Long-term problem
- Container can create circling,
kinked, girdling, or bound roots - Defects not always visible with
containers - B&B and bare root are generally
free of defects
17
Q
To prevent root defects
A
Containerised stock
should be replanted
into successively
larger pots before
their roots reach the
edge of the container
18
Q
Root desiccation
A
- Implications for posttransplant survival
- Soil remaining in
contact with roots in
containers and B&B
productions types
minimises root
desiccation - Bare root susceptible to
desiccation
19
Q
Staking or guy wires
A
- Implications for stability,
production cost - Containerised trees are
susceptible to instability - Field-grown B&B and
bare root trees produce
anchoring structural
roots - Undercutting and/or
wrenching may lead to
temporary instability
20
Q
Weed/Grass Competition
A
- Implications for water/nutrient availability,
production cost - Container-grown trees subjected to little
competition - Limited by surface area of container
- Easily removed
- B&B and bare root are field grown, so
competition can be significant - Weeds/grass can be removed mechanically or
chemically or with mulching at a cost
21
Q
Growing Media
A
Implications for optimal growth in nursery, transportation, post-transplant survival due to water loss, production and planting cost.
22
Q
Potting mix used in containers features
A
- Mainly organic material (e.g., peat, bark), but can
include coarse sand - Light weight → good for transportation/handling, but
loses water to surrounding soils post-transplant - Sterilised → avoids weeds and pathogens or diseases
- Fertilised → slow-release fertiliser to provide nutrients
- pH → appropriate for species being grown
23
Q
B&B and bare root are field grown
A
- Heavier soils → better water retention, but poor for
transportation/handling (B&B only) - Fine-scale control over pH, fertilisation is more difficult
- B&B takes soil to destination, bare root leaves soil at nursery
24
Q
Irrigation and fertilisation
A
- Implications for water/nutrient
availability, production cost - Container-grown trees have access to
limited soil volume, so water and nutrient
availability may be limiting - Irrigation systems provide required water
and nutrients to containers - B&B and bare root trees are field grown,
so water/nutrient availability is less
limited → large soil volume - Drought or nutrient poor soils still require
management
25
Q
Stocking implications
A
- Implications for production cost, economies
of scale, pricing for consumers, profit for
growers - Container-grown trees can be grown
intensively - Bare root can be grown somewhat
intensively, but require space between rows
for undercutting/wrenching machinery - B&B are grown extensively, thus allowing
tree spade access to disinter tree for
transplanting - Smaller trees can be balled and burlapped by
hand, requiring less access space
26
Q
Root ball weight of different production methods
A
- Implications for handling
and transportation →
production and planting
costs - B&B very heavy,
requires specialised
machinery - Bare root light, can be
moved by hand, by
individuals - Container weight
depends on size
27
Q
While in production temporary storage may need to be used to prevent descication …
A
This has an implication on tree survival, production and planting costs
Weather and logistic traits may also be why trees require to be stored
28
Q
Each different production techniques has implication on the easy of planting
A
29
Q
A
