Grafting LAT 109 Portland Community College

History China 1560 B.C. (non-verifiable) 424 B.C.E. by one or more of the followers of Hippocrates Aristotle ( B.C.) wrote about grafting Theophrastus ( B.C.) wrote about grafting Roman empire (common practice) Paul the Apostle –discussed grafting between the good and the wild olive trees (Romans 11:17-24) 16 th century – cleft and whip grafts widely used in England; knowledge that the cambium had to line up; wet clay and dung used to protect grafts 17 th century – grafted orchards planted in England

Earliest verifiable written record of grafting Some trees however, grow from grafts implanted into other trees: they live independently on these, and the fruit which they bear is different from that of the tree on which they are grafted. This is how: first of all the graft produces buds, for initially it still contains nutriment from its parent tree, and only subsequently from the tree in which it was engrafted. Then, when it buds, it puts forth slender roots in the tree, and feeds initially on the moisture actually in the tree on which it is engrafted. Then in course of time it extends its roots directly into the earth, thorough the tree on which it was engrafted: thereafter it uses the moisture which it draws up from the ground. - On the Nature of the Child, thought to have been written in about 424 BCE by one or more of the followers of Hippocrates

History China 1560 B.C. (non-verifiable) 424 BCE by one or more of the followers of Hippocrates Aristotle ( B.C.) wrote about grafting Theophrastus ( B.C.) wrote about grafting Roman empire (common practice) Paul the Apostle –discussed grafting between the good and the wild olive trees (Romans 11:17-24) 16 th century – cleft and whip grafts widely used in England; knowledge that the cambium had to line up; wet clay and dung used to protect grafts 17 th century – grafted orchards planted in England

Terms Grafting – art and science of connecting two pieces of living plant tissue in such a manner that they will unite and subsequently grow and develop as one composite plant. Scion – piece of detached shoot with several buds and of the chosen variety that when attached to the rootstock will become the shoot system of the grafted plant; one year old Rootstock (understock, stock)- lower portion of the graft that becomes the root system of the grafted plant; maybe seedling or clonal

Terms Vascular cambium – thin layer of meristematic cells between the xylem and phloem Callus – mass of parenchyma cells that develop from and around wounded plant tissue; both the scion and rootstock

Uses (ornamental) Perpetuating clones that cannot otherwise be propagated Benefits of certain rootstocks (size, disease resistance) Change cultivars of existing plants (topworking) Hastening growth and maturity Special forms (cactus)

Top working

Grafted cacti

Factors influencing success Taxa Botanical relationship – The closer 2 plants are taxonomically, the more likely it is that they can be grafted successfully Polarity Temperature – moderate temperatures for callus formation Water status – avoid desiccation at the graft Growth activity Craftsmanship Disease

Incompatibility Union never forms Small number of unions form (low success) Dies eventually Deficiency symptoms Dwarfing Differential growth at the union

Incompatibility Union never forms Small number of unions form (low success) Dies eventually Deficiency symptoms Dwarfing Differential growth at the union

Biology/physiology of grafting 1.Line up vascular cambium of scion and rootstock 2.Wound response 1.Necrotic layer (both – 1 cell thick) 2.Callus formation (both – undifferentiated cells from under necrotic layer) 3.Callus forms an outer suberized layer – necrotic layer dissolves

Biology/physiology of grafting 3.Callus bridge formation 4.New vascular cambium in the callus bridge 1.Differentiation of callus tissue to cambial tissue 2.Takes 2-3 weeks in woody plants 5.Secondary xylem (1 st ) and phloem (2 nd )

Stem cross section

Tools and supplies Knife (sharp!) – flat on one side, slope on the other Tape – rubber, parafilm, plastic, raffia, twine, etc Wax “Omega” grafting tool

Single-workedDouble-worked

Approach grafting or in-arching

Whip and tongue graft

Cleft graft

Saddle (wedge) graft Saddle Wedge

Side & veneer graft Side Veneer

Grafting tool V Omega T