Mr. Amling instructs Melanie Longwell in use of the draw knife
Judson Botany Students Learn
Bark Approach Graft

Article and Images by Thomas H. Wilson

   
Mr. Jeff Amling, sociology assistant professor at Judson College, recently conducted a botany laboratory exercise in grafting pecan trees. Jeff learned his grafting skills from his father, Harry J. Amling, Professor Emeritus at Auburn University. The two unproductive Cheyenne pecan trees were in the garden of Thomas Wilson, Judson Professor and botany class instructor.
   
Amling selects the pecan limbs to graph
Mr. Amling explained that the Cheyenne pecan variety has proved unproductive in the southeast and that grafting quality fruiting stock would correct the problem. Amling brought scions of Creek and Amling varieties for grafting. The Amling variety comes from a chance seedling found in Dr. Amling's pecan orchard near Auburn, Alabama.
Mr. Amling selects the limb for the first graft
Mr. Amling trims limb to be grafted as Dr. Wilson assists
Mr. Amling teaches students about vascular tissues involved in grafting
Mr. Amling demonstrated how to age the tree by counting growth rings and he pointed out the difference in bark and wood (Xylem). A short lesson in tree physiology helped students understand the biology of the bark approach grafting technique.
A draw knife was used to expose the bark tissue. It is important to match the vascular cambium of the grafted scion to that of the pecan limb.
A special heavy-bladed grafting knife was used to cut through the bark layer. The narrow strip of bark is peel back and the scion is inserted in the space. The vascular tissue of the scion and the limb are in contact and this allows for the graft to grow into the tree.
Amling uses a draw knife to expose the bark tissue
Amling cuts the limb bark for insertion of scion
Amling secures graft with nylon tape
Amling pours Lindane insecticide to protect tissue from pests
Mr. Amling used nylon tape to secure the graph to the limb. Lindane insecticide was poured onto the grafted area to protect the exposed tissue from pests.
A plastic bag was placed over the graft to maintain a high humidity around the exposed tissue.
Plaslic bag is used to maintain a high humidity
Aluminun foil is wrapped around graft area
Aluminum foil was wrapped around the graft to shield the tissue from the light and to reflect heat. Tree tissues heal best in the dark.
The grafted scion was painted with white latex paint to protect against water loss and to reflect heat.
Bud-break on the grafted scions should occur within about 21 days. After the new stems grow about a foot in length, they will be secured with a stake to prevent wind damage.

Amling predicted the grafted trees should start producing pecans in about three to five years.
Emily Gamble paints the scion with white latex
   
   
   
©Judson College, 2000
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