Several of our seedling Crath trees have nuts this year. In all cases,
there are only a few nuts on each as our trees are still quite small. I
had to hand-pollinate the blossoms this spring; this resulted in a
rather small percentage of sets; then the curculio took a rather severe
toll, so we will have only a few of each variety.
In 1944 one of our seedlings bore 12 nuts. These were so good that we
have named the variety "Littlepage" in honor of the late Thomas
Littlepage, and are having it patented. We have published a little
booklet on this variety, and upon request, we will be glad to mail a
copy to anyone interested.
This is about all we have to offer at this time in regard to our variety
tests.
We have a problem which I wish to bring before the members of the
Association. It is that of controlling the butternut curculio. This
insect is very bad on butternut, heartnut and Persian walnuts, with us
it does not attack black walnuts or hickories. I fear that it is going
to prove hard to control, as the larva is of the boring type, being
found inside the green nuts, inside the new growth of the terminals and
in the fleshy part of the leaf stems. In these places it cannot be
reached by poisons. It appears that we will have to work entirely on the
adult beetles. These eat very little and seem to make puncture-like
holes, eating little outside tissue but mostly deeper tissues, thus
poison will probably have to be applied heavily in order for it to get
enough to kill it. D.D.T. is not effective against the apple and plum
curculio so probably will not be so against the butternut curculio. It
might be effective to apply a heavy coating of D.D.T. bearing dust under
the trees so that as the larva drop to the ground to pupate, they will
be killed while the adult beetle may be immune to D.D.T., it is not
likely that the pupa could survive in heavily impregnated soil.
The adult beetles are present from the time the first leaves appear
until late summer. A spray of 4 to 5 pounds of arsenate of lead and 12
to 15 pounds of hydrated lime to 100 gallons of water, applied once a
week throughout the early part of the season might prove effective but
it will certainly prove expensive.
Planting of the affected varieties at some distance from woodlands and
wild butternut trees is helpful in avoiding this insect, but as the
trees grow older the pests may build up a population of their own. Some
sections of the county may not be affected; I hope so.
Maybe we can get some of our entomologists to work on this insect. Let's
put a little pressure on our State Experiment Stations and the U. S.
Department of Agriculture. Maybe Mr. Reed can help us.
Another subject I wish to mention is that of hardiness in nut trees. In
reading the NNGA reports and in some of the letters I have received, I
have found that many people confuse killing of the young leaves in the
spring by late frosts, with winter hardiness. In my opinion there is no
connection at all. I have seen many trees that were not hurt at all by
-34 deg.F. in mid-winter yet had all of their leaves killed by a late frost
in the spring. In fact all species and varieties of hickory and walnut
will have their leaves killed by a hard frost if the leaves have opened
out of the buds; this includes our native wild trees as well as the
grafted varieties.
The only hardiness against late spring frosts is the characteristic of
leafing out late, thus escaping most of such frosts. Of the different
species, the black walnuts seem to be best protected in this way, with
the hickories next and the heartnuts and Persian walnuts least
protected. Of course there is a considerable varietal variation within
each species.
Then the protection we can provide, is to plant nut trees on side hills
or other high ground where there is good air drainage, thus avoiding the
frost pockets. Of course many want to plant nut trees and have no place
except in low frosty sites. To these I say that they can expect to lose
an occasional nut crop by these late spring frosts, but that only in
exceptional cases will the trees suffer permanent injury. In years when
the crops are lost the trees will still be good ornamentals and shade
trees. My door yard is quite a frost pocket, yet I have lost only one
crop of heartnuts out of four or five crops, no permanent injury to the
tree.
Yield and Nut Quality of the Common Black Walnut In the Tennessee
Valley[12]