y destroyed simply
because they had been forgotten. The next highest mortality cause
reported was pre-establishment loss; this was blamed for 9 percent of
the deaths. Losses resulting from delayed planting were placed in this
category, also those where the report was "trees failed to leaf out."
Insects and diseases were reported as causing 7 percent of the
mortality.
=Growth and Bearing.= Those who plant improved black walnut trees
naturally want to know how soon they will begin bearing. This survey
shows that bearing begins much earlier than most people thought. Trees
in 32 percent of the plantings established between 1939 and 1944 were
bearing by 1946. Of these 342, 113 began bearing 2 to 4 years after
planting; 120 bore their first crop after 5 years; 109 began bearing
after 6 to 8 years (Table 2). According to the reports, the earlier
plantings were slower to come into bearing than the later plantings.
This probably is not a true picture. We suspect that after six or eight
years the actual date of first bearing had been forgotten in many cases.
Growth was reported in terms of total height for each tree. These
heights were then converted to annual growth rates for trees 3 to 8
years old and placed in arbitrary classes are follows: low (less than 1
foot) medium (1 to 2 feet), and high (over 2 feet). Test plantings in
North Carolina had the highest growth rate; those in Mississippi, the
lowest. In other states, growth rates fell between these two and were
quite similar for the most part (Table 3). Average for all trees was 1.6
feet per year. Trees averaging less than one foot of height growth per
year were slow to come into bearing. Only 14 percent of the trees in the
low growth rate class were bearing. On the other hand, 71 percent of the
trees with a high growth rate had come into bearing. Growth of black
walnut, following recovery from transplanting shock, depends on site
conditions and tree care. Trees set in fertile soil with an adequate
moisture supply and kept free of livestock and other damage make rapid
growth. Trees set in poor, thin or droughty soil do not make much growth
if they survive at all. Black walnut is very sensitive to any wounds
and, if subject to mechanical or livestock damage, growth is retarded.
Cases of exceptional growth and bearing were reported. One in eastern
Tennessee is worthy of brief description. There were two trees in this
planting set approximately 40 feet apart. One was on th
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