disease. The pecan
has fungus root-rot and various wood rot fungi besides the leaf
diseases. It also has several other troubles more or less serious.
Occasionally in the pecan groves you will find these remarkably white
mildewed nuts. That gives way to spraying. Another disease is an
internal spot on the kernel which Mr. Rand has been working on and which
seems to be due to a fungus. We don't know how to prevent that yet. The
pecan has a fungus attacking it that is very similar to the bitter rot
of the apple. The pecan anthracnose looks like the bitter rot, has the
same pink spore masses and you will be able to recognize it. That may be
prevented by spraying, but it is, fortunately, not a serious disease.
The northern nut grower will not have so much trouble with that, as it
is a southern disease. Here is a physiological trouble that causes
blackening of the young nuts on the inside. It appears to me to be due
mainly to wet weather, but I don't know its exact nature. It came
primarily on a pecan raised in the semi-arid section of Texas and
brought into South Carolina, and by the way you can get as much trouble
in adapting trees from the western to the eastern United States as in
bringing in trees from other countries. In parts of semi-arid Texas the
trees are supplied with moisture by sub-irrigation and when we move
those pecans to the humid East we get almost as much non-adjustment as
when we bring in foreign things. I would suggest that these pecans from
western Texas are the very ones to take to Utah and California rather
than those from the eastern part of the United States. They are adjusted
to dry seasons with moisture at their roots and you will get the best
results from them when grown under irrigation.

I will now take up the walnut, _Juglans nigra_, the common black walnut.
There are twenty species of fungi which are known to attack it. Quite a
good many of these attack the twigs and cause them to die, and probably
half are leaf diseases. One, commonly called white rust, a disease of
the leaves, attracts mycologists in collecting, but it has never been of
serious economic importance.

Now, as to the butternut, _Juglans cinerea_. It has about nineteen
species of fungi known to attack it, but probably many more will be
found when the nut is thoroughly studied.

_Juglans regia_, the cultivated Persian walnut, has only about twelve
species of fungi recorded from it in this country. There are,
undoubtedly, more