by Joe Orsi
This year I topworked numerous varieties on to most of my apple trees. Topworking a tree enables you to evaluate multiple varieties in a relatively short time frame and in a limited amount of space. Of course, tills is as long as you can relocate and identify your topworked varieties. Because I do not trust the longevity of external labels, I came up with an innovative technique to record graft positions on a tree using a measuring tape, a compass, a pencil, and a notepad. Even if you are sold on external labels, this technique would be a good way to “backup” those labels.
To record graft position on a particular tree, I initially note the scion variety used and its number of buds. Then, I note the distance and direction (compass bearing) from where the base of the tree meets the ground to where the new graft union is on the tree. Using this technique, I can readily locate a grafted variety on any of my trees. This year I recorded 118 grafts of 66 varieties on 35 trees. Here is an example of how I would record four grafts of two varieties on a Yellow Transparent:
Early Harvest (NW- 68”-6B; SE-76”-2B), and Carroll (E-45”-3B; S-40”-8B)
Date: 1 April 1995
Mother tree: Yellow Transparent on Antonovka (planted 1991, plot B)
In order to relocate the underlined graft of Early Harvest, I would measure 68” up from where the base of the tree meets the ground in a NW direction. There, I would hopefully find a graft union with a six bud scion on it. I painted the scions topworked last year a white color so they wouldn’t be confused with the scions topworked this year. To make identification of topworked varieties even simpler, I try and graft different colors of apples on to a particular tree. Although from past experience the “true” colors of some apples often don’t materialize under Alaskan growing conditions.
Over time, the measured distances from the trunk base to the graft union may shrink due to trunk and limb expansion; however, this reduced distance should be relatively the same for all grafts on a particular tree. The compass bearing from the base of the trunk to the graft would likewise not substantially change unless the tree was moved or the limb that was grafted on to broke off.