Grafting Terms Flashcards
1
Q
Grafting
A
- The art of joining two pieces of living plant tissue together in such a manner that they will unite and subsequently grow and develop as one composite plant
2
Q
Budding
A
- A form of grafting that uses a smaller scion piece - sometimes just a piece of the stem with an axillary bud
3
Q
Bark Slipping
A
- the vascular cambium is actively dividing, producing young thin-walled cells on each side of the cambium
- these newly formed cells separate easily from one another, so the bark “slips”
4
Q
7 points
Reasons for Grafting
A
- perpetuating clones
- combining different cultivars into a composite plant (rootstock: dwarfing, drought tolerance, disease resistance)
- obtaining special forms of plant growth ( standards, weeping plants)
- changing cultivars of established plants (topworking)
- reducing time to flowering
- tree repair
- disease indexing
5
Q
5 requirements
Requirements for a successful graft union
A
- compability between graft partners
- proper cambial association
- proper timing (scion - dormant; rootstocks - often active)
- protect graft union from desiccation
- post grafting care
6
Q
Bench Grafting
(Bench Working)
A
- is done with bareroot rootstocks or rootstocks in containers
- this is done on a bench in a protected environment
7
Q
Field Grafting
A
- the grafting is done in the field
- take place at a time of the year when favorable temperatures are expected and the vascular cambium is an active state
- these conditions generally occur during the spring months
- includes crown grafting, top-grafting, topworking, and repair grafting
- field grafting of decidious plants is done from late winter to late spring
- grafting should take place shortly before new growth starts
- the scions should be prepared from mature, dormant wood of the revious season’s growth
8
Q
Crown Grafting
A
- grafts made near the root-shoot junction (which is the junction of the root and shoot system)
- in earlier times, it referred to grafting several scions in a crown-like circle onto an established larger rootstock
9
Q
Top Grafting
A
- are grafts made in the top of the rootstock
- basically any graft that is not made at the bottom of the rootstock close to the ground (which is crown grafting)
10
Q
Topworking
A
- The grafting of a new cultivar onto established trees in the orchard
11
Q
Scion
A
- The top part of the graft
- A short piece of shoot or a single bud
- a short piece of detached shoot containing several dormant buds
- becomes the new shoot system of the graft
12
Q
Rootstock
(Understock)
A
- the lower or underground portion of the graft
- will develop into the rootsystem of the grafted plant
- could be a seedling, cutting, or root piece
- could have roots already or be just a stick
13
Q
Seedling Rootstocks
A
- rootstocks propagated from seed
- can be mass-produced relatively simply and economically
- usually virus-free
- tend to be more deeply rooted and more firmly anchored plants than clonal rootstock
- may show genetic variation leading to variability in growth and performance of the scion variety
14
Q
Clonal Rootstocks
A
- vegetatively propagated by stool layering, rooted cuttings, or micropropagation
- are desired for uniformity, stree and disease resistance
- also influence the size and growth habit of the grafted plant and flowering and fruit development of scion
15
Q
Interstock
(Intermediate Stock)
(Interstem)
A
- a piece of stem inserted by means of two graft unions between the scion and the rootstock
- used if scion and rootstock are incompatible - use interstock as middle man
- used to produce special tree forms (make standards)
- used to control disease (e.g. fireblight resistance)
- used to take advantage of their growth-controlling properties
- Double working: the grafting or budding of an interstock between the rootstock or scion
16
Q
Double Working
A
- The grafting or budding of an interstock (interstem) between the rootstock and scion.
- to propagate a plant by grafting or budding a scion to an intermediate piece of one variety on a rootstock of another variety
- as for overcoming incompability between scion and stock or for providing a superior trunk
17
Q
Callus
A
- the mass of parenchyma cells that develop from and around wounded plant tissues.
- It occurs at the junction of a graft union, arising from the living cells of both scion and rootstock.
- The production and interlocking of these parenchyma (or callus) cells constitute one of the important steps in callus bridge formation between the scion and rootstock in a successful graft.
18
Q
Cambium
A
- a thin tissue located between the bark (periderm, cortex, and phloem) and the wood (xylem)
- its cells are meristematic
- they are capable of dividing and forming new cells
- cambial regions of the scion and rootstock must line up so that the vascular systems can reattach in the graft union
20
Q
Graft Failure
A
- An unsuccessful graft caused by atanomical mismatching, poor craftsmanship, adverse environmental conditions, disease, or graft incompatibility
- sings of graft failure: suckering from below graft union, dissimilar growth between the rootstock and scion (one side grows a lot faster than the other), crown dieback, and the toppling of the tree with a clean break at the graft union
21
Q
Graft Incompatibility
A
- An interruption in cambial and vascular continuity leading to a smooth break at the point of the graft union, causing graft failure.
- It is caused by adverse physiological responses between the graft partners, disease, or anatomical abnormalities.
- can lead to disimilar growth between the rootstock and scion
- can be delayed for years before failing
22
Q
Grafting and Budding Knives
A
- are flat on one side and have a tapered edge on the other to make a sharp, clean cut
- either a folding or fixed blade
- the fixed type blade is stronger, and if a holder of some kind is used to protect the cutting edge, it is probably the most desired
- a well-built, sturdy knife of high-carbon steel is essential
- the metal flap opposite the sharp end of the blade is used to separate the bark during the T-cut of the rootstock. The quill is also used to separate the bark during T-budding
- must be very sharp at all times
- good knives will hold that sharpness for longer
- look like pocket knives
