8 9
80 x 80 " 6
100 x 100 " 4

To find the number of trees that can be set on an acre for any
distance, not given in the above table, multiply the distance
apart in feet together and divide the product into 43,560, the
number of square feet in an acre. The result will be the number
of trees which can be put on an acre of ground.

PLANTING SYSTEMS.

For setting orchards a number of different systems may be used, but the
two best adapted to the pecan orchard, are the square or rectangular and
the hexagonal or septuple. If mixed plantings, such as pecans and
peaches, are to be made, then the quincunx system should be used and a
peach tree set in the center of the square or rectangle formed by every
four pecan trees.

_Square or Rectangular System._ In this system is included only
the methods of setting trees in rectangles, either square or
oblong. It is by far the most commonly used of all the systems,
and the ease with which a field can be laid off in rectangles,
is greatly in its favor.

The rows of trees intersect each other at right angles, and
cultivation may be carried on conveniently either crosswise or
lengthwise of the orchard. The planter has the choice of
placing the trees the same distance apart both ways, or of
planting them closer together in the rows than the distance
between the rows.

[Illustration: FIG. 30. Rectangular Planting System.]

It has been argued that space is not equally divided among the
trees, and while this is apparently true, yet, on the other
hand, the roots of pecan trees, in most cases, penetrate and
permeate all the space allowed in ordinary distances. The roots
will certainly secure all the food and moisture in the top two
or three feet of soil.

When trees are to be planted by this system, the stakes must be
set so as to be exactly in line, whether viewed from the end or
from the side of the field.

_Hexagonal, Septuple or Equilateral Triangle System._ By this
system, six trees are set equidistant from a seventh placed in
the center. The basis of the system is not the square, but the
circle, since the radius of the circle is approximately equal
to one-sixth of the circumference of the circle. The name
septuple, sometimes applied to this system, refers to