ecan is 79%, that is it will grow and
bear well where the pecan units are as low as 79% of those of the place
of its origin or to use rough figures, 80%.

When we come to ascertain the pecan units of the locations where the
northern pecan grows and bears well we will consider Evansville and
Vincennes, Ind., as places where it bears well; Burlington, Ia., as a
place where it does quite well, but not as well, as in Evansville;
Clinton, Ia., as a place where trees are growing well but where they
bear a large crop only once in several years; and Charles City, Ia., as
a place where the pecan does not mature its nuts. The pecan units are
also shown for several important places outside of the native pecan
area.

Highest Lowest Average

Evansville, Ind. (1919) 147.5 (1917) 116.4 135.7
Vincennes, Ind. (1914) 144.7 (1918) 123.1 130.8
Burlington, Ia. (1914) 125.8 (1917) 90.2 108.4
Clinton, Ia. (1914) 109.2 (1917) 75.3 94.9
Charles City, Ia. (1914) 91.2 (1915) 65.4 78.5
New York City (1914) 101.2 (1917) 85.2 94.3
Lancaster, Penn. (1919) 108.7 (1917) 84.9 98.4
Gettysburg, Penn. (1919) 108.4 (1916) 89.4 100.7
Cincinnati, O. (1914) 131.7 (1917) 88.9 109.5
Baltimore, Md. (1919) 127.2 (1917) 106.7 121.0
Washington, Md. (1918) 126.8 (1917) 104.7 119.3
Hartford, Conn. (1919) 88.9 (1917) 74.8 85.1

If we consider that Evansville and Vincennes are the center of the pecan
district near which most varieties have originated and that a place
should have 80% as many pecan units as in this Evansville district in
order to have the northern pecan do well, a place should have 105 pecan
units in order for one to feel reasonably certain that the northern
pecan will do well there. It will be both interesting and instructive to
see how well the applications that may be made from the conclusions
compare with observed facts.

We know that there are large numbers of pecan trees at Burlington, Ia.,
and that the trees grow and bear well. Its pecan units are 108.4. We
should conclude that at Baltimore and Washington with pecan units at
121.0 and 119.3 respectively that pecans would grow and bear well. There
are pecan trees over 100 years old at Marietta, Md., which is half way
between Baltimore and Washington. These trees bear nuts and although it
has not been possible to