n opportunity for selection on somewhat the same basis as
the East Malling clones of apple rootstocks which produce different
sized scion varieties after grafting. Unfortunately, no non-suckering
desirable clones of filberts have yet been reported and even the
non-suckering Turkish tree hazel is grown from seed when such rootstocks
are used (16).

Propagation by Cuttings

Gellatly (7) quoted the success of the East Malling Research Station in
England in rooting cuttings of walnuts grown in the greenhouse and
reported on his own experience in producing short roots on dormant
cuttings of heartnut and Persian walnut. The writer (15) has
occasionally produced roots on softwood cuttings of pecan and hickory
set in a mist humidified greenhouse but the cuttings did not survive.
Mist humidification has been a distinct aid in retaining foliage on
softwood cuttings of filbert and Chinese chestnut until roots were
formed but unless the axillary buds were developed sufficiently to make
new growth immediately thereafter, little or no survival was secured.
Apparently when the cuttings were succulent enough to form roots the
buds were too immature to put out new shoots. If one waited until the
buds were developed the tissue at the base of the cutting was too highly
lignified for root formation. The use of synthetic plant hormones on
cuttings of nut-tree species has been of questionable value.

Propagation by Layers

Mound layers are used quite successfully for the propagation of filbert
varieties but have not proven of value with other nut-tree species.
Chinese chestnut has been reported to layer easily but experiments with
both mound and trench layers of selected varieties of this species at
the Glenn Dale, Maryland Station of the U.S. Department of Agriculture
gave negative results. The writer (15) has occasionally rooted pecan,
hickory, and Chinese chestnut by aerial layering. A marcot box
containing sphagnum moss kept moist by a glass wick immersed in water
from a bottle at the lower end was employed. The time and labor involved
were so great that the experiments were discontinued.

Propagation by Grafting

Bench grafting of walnuts and hickories has been adequately described by
Bernath (3), Hardy (8), Lounsberry (10), Slate (24), and others. This
method has been tested on a commercial basis and apparently should be
considered as one of the most efficient ways to produce nut trees
quickly and cheaply in large quantiti