Rootstocks for walnuts and hickories are very easily grown from seed.
Chestnuts are grown with variable success, and it would seem that
particular care in drainage of the seed bed, and possibly the use of one
of the seed fungicides, should improve chestnut germination.
The present trend in the propagation of fruit trees is toward selection
of particularly suitable rootstocks. Do some nut tree seedlings accept
grafts more readily than others? We do not know. Numerous writers have
discussed the idea of varying degrees of compatibility of rootstocks
with scions and Jones[1] has brought together considerable evidence to
relate incompatibility among plants with something parallel to allergy
in animals. Initial growth of the scion leads to a flow of foreign
bodies into the stock. The theory is advanced that the stock develops
antitoxins to these foreign bodies which succeed in killing the scion a
few weeks later.
If a particular strain of nut tree stock is some day found to be of
particular value for grafting, or for propagation of a disease resistant
type, as in the chestnut, the propagation of such stock vegetatively
would be essential. A present illustration is the series of Malling
apple rootstocks which are grown from cuttings.
I have tried many times to grow chestnuts from cuttings with no success.
A few experiments now in progress are limited to Malling IX apple stocks
which I assume are not especially difficult to root. I am trying several
modifications of a principle of making the cuttings at some time after
girdling the stem. The hope is that in this way there will be
accumulated at the base of the cutting more than the usual reserve of
nutritive elements together with whatever plant wound hormones and plant
growth substances the twig is capable of synthesizing.