Twenty years of experimenting with pecan trees at the Iowa Park station
have revealed that pecans in the Wichita irrigated valley of Texas do
very poorly in buffalo grass or Bermuda sod, much better when given
clean cultivation, but best of all when planted with or near evergreens,
particularly conifers.
[Footnote 15: Forty-Eighth Annual Report, Texas Agricultural Experiment
Station. P. 42. 1945.]
In 1926 some pecan trees were set along the west line of the farmstead.
Most of these died soon after setting and the few that survived did not
grow satisfactorily. Later, a general farmstead improvement program
called for Arizona cypress along this line. In 1933, when these pecan
trees were seven years old, they had made little growth and were in such
poor condition that it was decided to ignore them and set the cypress on
equal spacings. Some of the cypress trees were placed very near pecan
trees while others were farther away. None of the pecans were removed,
however.
As the cypress trees grew, the pecan trees near them began to take on
new life, while the isolated pecan trees continued in their unthrifty
state. As the years passed the pecans with companion cypress trees
continued to increase in health and vigor until there was no doubt about
the favorable influence of this companionship. At the time the cypress
trees were set close to the older pecans, other pecan trees were being
set in various locations on the farmstead; some in open sod and others
with or near evergreens of various types. The behavior of these trees
also confirms the value of companion evergreens for pecans in the
Wichita irrigated valley.
At the age of seven years the pecan trees were about the same size and
in equally poor condition. The treatment as far as cultivation and
irrigation is concerned has been the same. Hence, the great contrast in
size of the pecan trees is attributed to the favorable influence of the
companion conifers.
[NOTE BY EDITOR--Heavy shade can reduce soil temperature, on summer
afternoons, more than 20 deg.F six inches underground. This may largely
explain the benefits of companion trees.]
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