Grafting Factors/Environmental Control Flashcards Preview

Grafting and Budding > Grafting Factors/Environmental Control > Flashcards

Flashcards in Grafting Factors/Environmental Control Deck (17):
1

Budding Rubbers

Budding rubbers must be tied
with a half
-
hitch or slip knot,
which is done at the final turn of
the tape by slipping it under the
previous turn.
Budding rubbers do not
deteriorate in full sunlight and
must be removed later to prevent
girdling the plant.

2

Callus Bridge

Until vascular connections are
formed between the rootstock
and scion, the callus bridge
provides the initial pathway for
water, bypassing damaged
xylem vessels and
tracheids
of
the scion and rootstock.

3

Delayed grating incompatibility

Failure to form a successful
graft or bud union.

Incompatible rootstock
-
scion
combinations can completely
fail to unite.
Frequently they unite initially
with apparent success, but the
graft fails over time. This
process is referred to as
delayed incompatibility

4

Graft incompatibility
cellular recognition

One of the symptoms of
incompatibility in grafts between
distantly related plants is a
complete lack, or a very low
percentage, of successful unions.
Grafts between some plants
known to be incompatible,
however, initially will make a
satisfactory union, even though
the combination eventually fails

5

Graft union formation

The graft union is initially
formed by rapidly dividing
callus cells, originating from
the scion and rootstock, which
later differentiate to form the
vascular cambium (a lateral
meristem) and the associated
vascular system.


The development of a compatible graft is typically comprised of
several major events:
adhesion
of the rootstock and scion,
proliferation of callus cells at the graft interface or
callus bridge,
and
vascular differentiation
across the graft interface.

6

Grafting case

Unwaxed
grafts can also be simply
protected by a polyethylene bag or
even glass jars. Care should be
taken to shade grafts to prevent
heat buildup under the cover.

Waxing may be omitted if
grafts are to be protected
from drying by packing the
grafts in boxes or frames
containing slightly moist
peat.

7

Grafting clips

Plastic graft clips are used in
manual and machine splice
grafting of vegetable crops.

8

Grafting wax

Grafting wax seals over the
graft union, thereby
preventing the loss of
moisture and death of the
tender, exposed cells of the
cut surfaces of the scion and
rootstock.
These cells are essential for
callus production and healing
of the graft union

Hot waxes require heating to
keep the wax liquid.
They are special combinations of
waxes that have a low melting
point.

9

Grow straights

Grafted plants are usually
staked to stabilize the new
shoot growth and initiate a
straight upright trunk

10

Hot pipe callusing system

With some difficult to graft
species, a warm temperature
around the graft can be
beneficial.
The hot
-
pipe callusing
system warms the graft
union to about 80 degrees F.
but keeps the roots and buds
on the scion cool (about 45
degrees F.) to prevent their
premature growth.

11

Non
-
translocatable (localized)
graft incompatibility

This is a type of localized
incompatibility where contact
cells from the two partners fail
to recognize each other and do
not initiate callus formation.
A mutually compatible
interstock
overcomes
translocatable
incompatibility
between the scion and
rootstock

12

Nursery tape

Nursery adhesive tape is similar to
surgical adhesive tape but lighter
in weight and not sterilized.
Adhesive tape is useful for tying
and sealing whip grafts.
When this type of wrapping is
covered with soil, it usually rots
and breaks before any girdling
damage can occur.

13

Parafilm

Parafilm
tape is a self
-
sealing
tying materials which has been
used with successful results to
wrap graft unions rapidly and for
chip
-
budding roses.
This material is a waterproof,
flexible, stretchable, thermoplastic
film with a paper backing. The
film is removed from the paper,
wrapped around the graft union,
and pressed into place by hand.

14

Pathogen-induced graft incompatibility

Walnut blackline

Some delayed incompatibilities
are caused by viruses and
phytoplasma
(
mycoplasma
-
like
organisms).
Examples include cherry leaf
virus in walnut; Apple union
necrosis and decline; and
brownline
in prune caused by
tomato ring
-
spot virus.

15

Polyethylene tape

Clear or colored polyethylene
or polyvinyl chloride (PVC)
budding and grafting strips,
which are 0.5 to 1.3 cm (3/16
to ½ in.) wide and slightly
elastic, allowing for a more
secure wrap.

They are not self
-
adhesive and
require tying

16

Translocatable graft incompatibility

Translocatable
incompatibility includes certain graft/rootstock
combinations in which the insertion of a mutually compatible
interstock
does not overcome incompatibility. Apparently, some
biochemical influence moves across the
interstock
and causes
phloem degeneration. This may be the case with translocation of
prunasin
from a quince rootstock to a pear scion where it is
metabolized into hydrogen cyanide that poisons the graft union

17

Waxed string

Waxed string or twine adheres
to itself and to the plant parts
without tying a slip knot.
It should be removed following
healing of the graft union.