DISTINGUISHING CHARACTERISTICS OF SCIONS
Loss of identification markings from my grafted trees has, on occasion,
caused me much confusion. There was one time when I had from six to ten
varieties of hickories and their hybrids grafted on wild bitternut
hickory stocks, totally lacking in identification. Although this
disconcerted me considerably, I knew of nothing I could do except to
wait for the grafts to bear nuts and determine the varieties from these.
As I continued my experimental grafting, I made sure that the tags I
used were not only indestructible, but also secured to the grafts in
such a way that the action of the wind could not wear them out nor cause
them to drop off.
Not long after this had happened, I received from Dr. Deming a shipment
of about twenty varieties of hickory scions. While I was preparing this
material for grafting, I noticed that each variety could be readily
distinguished by its appearance in general and, specifically, by
differences in its leaf scars. I also noticed markings on the bark,
particularly the stomata, which differed with each variety. Color and
stripes added further differentiation. Although I also found variations
in the size and shape of the buds, I later discovered that these do not
always remain constant within a variety, but depend somewhat on each
season's growth. For instance, a second growth sometimes develops during
a favorable season with a large number of lateral buds growing out of it
like spines.
It seemed to me that if scions could be maintained in an approximately
fresh state, they would furnish a key by which any variety of graft
could be determined as easily as it could by its nuts. I therefore set
myself to preserve scionwood in its fresh state. First, I cut five-inch
pieces of plump, healthy wood, each piece having a terminal bud. I
placed these buds downward in large test tubes which I then filled with
pure, strained honey. Such models did very well for a time, but after
about a year, the honey crystallized and of course the scions were no
longer visible. I emptied the tubes and washed them, cleaned the scions
in warm water, replaced them and refilled the tubes with pure glycerine.
I submerged a thin, zinc tag, stencilled with the varietal name and bent
to conform with the contour of the tube, inside of each one as a name
plate which could not easily be lost or removed. I also labeled each
cork with the name of the variety enclosed so that any one of them
could be located when looking down at a nest of tubes in a vertical
position.
In order to display these preserved specimens at illustrated lectures, I
had a rack made of redwood, of a size to hold twenty tubes. The tubes
could easily be taken from the rack for closer observation by members of
an audience. I find this to be an interesting adjunct to various nut
culture exhibits I make in trying to promote nut culture education.
Since I was able to identify my unlabeled, hickory grafts by means of
this catalogue of submerged scions, I consider it of great practical
worth. At the present time, I have about 50 hickory specimens, a good
catalogue, although not a complete one. I see no reason why the same
thing could not be done with black walnut or any other kind of nut
scions.