TITLE:
Propagating Figured Wood in Black Walnut
AUTHORS:
James R. McKenna, Wayne A. Geyer, Keith E. Woeste, Daniel L. Cassens
KEYWORDS:
Juglans nigra, Figured Wood, Forestry Breeding, True-to-Type, Grafting, Clonal Forestry
JOURNAL NAME:
Open Journal of Forestry,
Vol.5 No.5,
June
15,
2015
ABSTRACT: Figured
black walnut lumber is a specialty wood product that commands a high price for manufacturing
fine furniture and interior paneling. Two common figured grain patterns occur
in walnut; they are known as “fiddle-back” or “curly” grain, depending on the
number of horizontal lines visible in the grain of the finished wood. The
occurrence of figured walnut in nature is rare and unpredictable. Trees that
have consistent figured patterns throughout the log are of exceptional value.
Conversely, trees with partial or spotty figured patterns are considered
defective and are reduced in value. Conventional breeding of seedlings, or
cloning figured trees by grafting, are possible methods to propagate figured
wood in walnut. The value of such material, however, will depend on figure
being expressed predictably. For breeding to succeed, the trait of interest
must be genetic and heritable. For clonal propagation to be effective, the
trait must be reproduced true-to-type. In this study, we evaluate the grain
pattern of both grafted and seedling walnut from several highly figured wild
selections. Logs from grafted trees of three clones propagated in the 1970s in
Kansas were evaluated. Only one log from one clone showed some figure in its
lumber. Ten-year-old seedlings from the figured walnut clone “Lamb” were grown
and cut in Indiana and evaluated for figured grain, and none showed any sign of
figured grain developing. Our conclusion is that figured grain in black walnut
does not propagate true-to-type through grafting or by growing open-pollinated
seed. Although evidence of some genetic control of figure was found,
environmental and other factors appear to play a greater role.