These observations are presented as a preliminary report of the results
obtained by three enterprising amateurs of nut growing in the western
counties of Tennessee, whose work points the way toward overcoming some
of the weaknesses previously encountered in nut culture in the northern
part of the cotton belt states. These growers are the "three R's" of our
Association in west Tennessee: Dr. Aubrey Richards of Whiteville, Mr.
George Rhodes of Covington, and Mr. W. F. Roark of Malesus. I am giving
this brief account of some of their experiences, with the hope that it
will stimulate others to try their methods under various conditions, and
to report their results at later N.N.G.A. meetings. We do not expect
these methods to work equally well in all parts of the United States and
Canada represented here today, but they are giving promising results in
the mid-South territory, and perhaps will have value in a wider area. As
Mr. Davidson has so ably done at this meeting in the case of his Ohio
plantings, we expect to give you a follow-up report on this work in west
Tennessee at the Toronto meeting or later.
"Twin-T" Budding in Chestnut Propagation
Of the nut trees grown in this area, the chestnut has been the most
difficult to propagate by budding. Nurseries in the upper South have
propagated their pecan and walnut trees mostly by patch-budding or the
similar ring-budding method, with very good success. When applied to
chestnuts, patch-buds have seldom grown. The common T-bud, likewise, has
been a general failure on chestnuts in America, though reported
successful in Japan. Chip-buds have not been much-better.
Several years ago, Dr. Max B. Hardy told me that the inlay bark-graft
had been used successfully with Chinese chestnuts at the U.S.D.A,
laboratory in Albany, Ga., following Dr. B. G. Sitton's use of this
method with pecans in Louisiana. (It is described in a bulletin from
Michigan State College, East Lansing, Mich.) I tried it in a small way,
and had some success using it on chestnuts in July and August. This
spring I suggested it to Mr. Roark and Dr. Richards, both of whom tried
it out, using Castanea mollissima stocks and various scion varieties.
Mr. Roark used the inlay bark-graft in the spring, topworking a C.
mollissima seedling with scions of the Colossal, a hybrid variety from
California. About 50 per cent of these have grown this year. Dr.
Richards tried it during July, on C. mollissima seedlings from a
different source. None of the Colossal would grow on his trees, but he
was partially successful with scions of the C. mollissima varieties,
Hobson, Carr and Zimmerman. He then devised a variation in the method
which was highly successful with C. mollissima varieties. This I shall
call the Richards "Twin-T" bud.
In "Twin-T" budding, a vertical slit is made in the bark of the stock.
Then horizontal cuts are made through the bark at both top and bottom of
the vertical cut. The bud piece is cut from the well matured part of a
current season's twig, leaving a rather thick slice of wood beneath the
bud. (It may be as thick as half the diameter of the twig.) The bud is
inserted in the stock as in ordinary T-budding, then wrapped with a
large sized rubber budding strip. (Westinghouse electrician's tape and
Curity adhesive tape have also been used. Some other brands poisoned the
buds.) The "take" of Chinese chestnut buds by this method has run from
60 to 90 per cent on Dr. Richards' trees of various sizes this year. In
a short nursery row, buds were placed under first or second year bark,
while larger trees were topworked by placing the buds mostly under the
bark of second year limbs.
The Colossal failed again on Dr. Richards' trees when budded by the
"Twin-T" method, but Carr and other Chinese varieties were budded
successfully. The graft-compatibility problem in chestnuts is one of
considerable complexity. Thus Carr, which has presented incompatibility
with certain stocks of C. mollissima at other places, grew on these
trees, and Colossal, compatible on another C. mollissima tree, failed on
trees which are apparently compatible with Carr. The Chinese chestnut
species varies in its graft-compatibilities possibly as much as in other
characteristics (growth, productivity, size and quality of nuts, etc.)
so that nut nurserymen should begin to select their seed for chestnut
understocks with a view toward getting strains with a greater degree of
compatibility to the leading scion varieties.
Mr. Roark has been able to propagate the Colossal upon its own roots by
layering a small tree in his orchard. Two limbs pegged into the ground
in the spring of 1945 had produced roots a year later, and were then
detached from the parent tree. This is a slow but sure method of
propagating nut tree varieties that are not congenial with the stocks
available for grafting or budding. He has also layered sweet cherries
and prune trees by this method which is described in U.S.D.A. Farmers
Bulletin 1501 with reference to filberts.