Module 8 - Grafting Flashcards
How old is the grafting technique?
Over 2000 years old
Define grafting.
The art of joining parts of plants together to unite and continue growth as one plant
What is the top portion of the graft called?
Scion
How long should a scion be and how many buds should be included?
several inches with 2-4 buds
What is the bottom part of the graft called?
Rootstock, understock, stock
What is the interstock?
Part of graft sometimes used to overcome incompatibility between scion and rootstock
What are 3 reasons to use grafting?
- cuttings are difficult to root
- make use of a rootstock that has desirable qualities (for ex. butternut attached to walnut not affected by fungus that attacks butternut)
- control the growth or size of plant (for ex. keeps dwarf apples dwarf)
Name the 13 types of grafting.
Whip-and-Tongue
Cleft
Side-Veneer
Splice
Saddle
Cutting
Double Worked
Root
Top
Bridge
Inarching
Bark
Bench
It is important to make sure the ________ ________ is aligned on all grafts!
vascular cambium
Name the graft:
o 6-15mm in size
o 1 cut 1” to 2” long through stem with second cut through middle called the tongue – do the same with the scion and the two lock in place.
o After graft bury it in moist material to encourage callusing (parenchyma cells develop) for 2-3 weeks
Whip-and-tongue
Name the graft:
o Using branch
o 8-10 cm in diameter, cut 1-2” down the middle on rootstock, then prepare a few scions from the donor that are tapered at the bottom 1-2” so that it will fit in the root stock.
o Afterwards add grafting wax to prevent loss of moisture
o Often done on fruit trees to change the cultivar of the fruit that is produced on one branch
Cleft graft
Name the graft:
o Remove wedge from root stock
o Taper scion so that it fits exactly in the wedge space
o Only once you have a successful graft can you cut the top of the root stock off.
o The new plant will grow at a slight angle at first
Side veneer
Name the graft:
o Done for plants that heal very quickly
o Simple cut, wrap with rubber bands or ties. No wedge to hold in place
o Generally limited to indoor grafting.
Splice
Name the graft:
o Remove wedge from scion
o Produce wedge from root stock
o Often done with plants that produce larger stems
o Important that the bark does not peel off from the underside of wood.
Saddle
Name the graft:
o Take two cuttings and attach one on top of the other
o Leafy scieon to a leafy cutting that’s unrooted
o Neither section is rooted
o Sometimes done with citrus and rose
o Scion and rootstock are both splice grafted
o Rootstock is treated with rooting hormone inserted in a rooting medium in a fog chamber (high humidity helps prevent loss of moisture from the graft
Cutting aka twig
Name the graft:
o In cases where scion is not compatible with rootstock
o Take a portion of stem from a 3rd plant for interstock which will allow the 3rd graft to be successful
o For incompatibility problems and produce dwarf trees
Double worked
Name the graft:
o Root stock is entirely root tissue
Root
Name the graft:
o Used to change the cultivar of a fruiting tree or grapevine
Top grafting / top working
Name the graft:
o Used to repair the injured trunk of a tree
o Prepare clean edges then insert scions from another plant, tapered on top and bottom. Insert on bark of the recipient tree
Now tree can transport water and nutrients through the scions
Bridge
What is inarching used for? How is it done?
To repair the roots of a tree.
o Prepare area to receive scions which are inserted into the ground and hopefully these will produce rots
Name the graft:
o Similar to cleft grafting
o Instead of cut down middle of branch, peel a little bit of bark and insert a scion that’s tapered into stock and sealed with wax
o Done in late winter/early spring when bark is able to easily peel away from the wood (slipping)
Bark
What is bench grafting?
Grafting in indoor, controlled conditions. Often use whip and tongue technique for bench grafting.
A ______ machine can cut grafts in a certain pattern
grafting
What is the physiology of grafting?
- Production of callus tissue (parenchyma cells that have not specialized)
a. No matter how well you make a cut there will be a little bit of space between the cut surfaces. This is why we need the calluses to form - Intermingling of parenchyma cells that make up the calluses
- Production of new vascular cambium – becomes one continuous vascular cambium
- Vascular cambium produces new xylem and new phloem!
What does it mean that polarity must be observed?
buds of the scion must be pointing upwards.
What are some considerations when choosing plant tissue and implementing a graft?
- Disease free
- Mother plants are true-to-type
- Buds dormant
- Vascular cambium must align
It’s important for the _____ _______ to be successful before the buds start to grow leaves.
bud union
How can you prevent graft from drying out?
Cover union in grafting wax so it won’t desicate.
Avoid exposing cut surfaces to dry air.
What is the ideal temperature range for performing grafts?
10-30 degrees c
What are the limits of grafting?
- Scion and rootstock must have some level of botanical relationship
- Plant parts from different cultivars of the same species can most likely be grafted successfully
Can you interchange rootstock and scion species?
No. For ex.
If you attach scion of peach onto plum it won’t work
If you attach a scion of a plum onto a peach it will work
