ich I did far more
experimental work than with the walnuts, was beclouded by the fact that
many successful, apparently compatible varieties, grew and throve on the
native bitternut stock without bearing fruit, except for just a few nuts
occasionally; and yet there was no apparent difference between the scion
diameter and the trunk diameter, nothing like the overgrowth of the
black walnut when grafted on butternut. So it took many years and a
different growth phenomenon to open my eyes as to what was the trouble
in getting hickories to bear on foreign root systems.

The final solution of the problem was determined by my observation this
year of grafted hickories of several sizes and ages were Weschcke
shagbark (_C. ovata_)[33] scions and other hickory scions, such as
Siers, Bridgewater, Deveaux, Beaver, and Fairbanks have been grafted on
the same tree to act as pollinators for the Weschcke, which is devoid of
pollen.[33] This year particularly, the difference in rate of growth
between two varieties grafted on the same stock was very apparent; in
every case all other varieties greatly exceeded the growth of the
Weschcke hickory, but in many cases, only the Weschcke hickory had any
nuts growing on the graft, and if there were any nuts on another graft,
there were but a few. In practically all cases, the diameters of the
scions of varieties of hickory other than the Weschcke were at least
twice the diameters of the Weschcke grafts, and the growth of all
varieties so grafted was healthy and vigorous and thoroughly compatible
with the native bitternut hickory root system.

Several years ago I had to trim some of these other varieties back in
order to allow the Weschcke graft to get more growth because it was so
backward in development that it looked as though it might be crowded out
of existence. It never occurred to me in those years that it was the
difference in rate of growth between the two varieties which was really
responsible for the difference in the diameter of the scion growth, and
not some accident of propagation. Now it is very apparent, from the many
examples that I have about me, that the Weschcke hickory is about
one-half as fast a grower as such varieties as Bridgewater, Deveaux,
Laney, Siers, and many others. This, then, accounts for the heavy
bearing of the Weschcke when it starts to bear on the bitternut roots,
and it also explains the lack of bearing in such varieties as Beaver,
Fairbanks, Laney, Siers, P