to the
tree.

Yield and Nut Quality of the Common Black Walnut In the Tennessee
Valley[12]

By Thomas G. Zarger, Tennessee Valley Authority

Black walnut occurs on open, non-crop land in the Tennessee Valley
region. Trees grow around the farmstead, along fence rows, and in
pastures on most farms. In recent years harvesting of walnuts for market
from these trees has increased significantly. Looking forward to a
fuller utilization of the wild black walnut crop, knowledge on the
bearing habits of these open-grown black walnut trees was required. To
supply this information a study of tree growth, nut yield, and nut
quality was undertaken in 1940. Results on nut yield available from this
study after six years are summarized in this report.

[Footnote 12: Contribution from TVA Forestry Relations Department,
Forestry Investigations Division on a project conducted in the Forest
Products Section.]

This study was initiated with the selection of representative open-grown
walnut trees throughout the Tennessee Valley. In 1940, 96 sample trees
were selected and 36 trees were added to the study in 1942. These 132
trees are located in 42 counties and afford a good representation of
age, size, and growth quality of open-grown black walnut. Each sample
tree has been visited annually. Entire crops were collected, carefully
weighed and sampled: tree diameters and other measurements were taken
for the tree growth phase of the study. When convenient, nuts were
hulled in the field with a corn sheller, but more often they were
brought to Norris and run through a hulling machine. After hulling, the
nuts were dried until cured, then a sample for each tree was tested for
percentage of filled nuts, nut weight, and cracking quality.

Yield

Results on nut yield and nut quality for the 132 sample trees have been
condensed to the presentation in Table 1. For the six-year period the
average tree in this study had a diameter of 13.3 inches and yielded 33
pounds of hulled, dry nuts a year. The yield of common black walnut
trees in the Tennessee Valley is characterized by extreme variation.
Tree size, of course, influences nut yield. One-half of the yields from
a 6-inch diameter tree ranged from no crop to 4 pounds of hulled, dry
nuts; whereas half the yields from a 22-inch tree ranged from 40 to 100
pounds. A yield of less than one-half pound of hulled, dry walnuts was
considered "no crop". Some individual trees had unusually high or