ly 30) I have been making
observations from time to time in different locations with special
attention to walnuts and with some to filberts. It is thought that
certain of these observations might be of interest to nut growers in
other areas, even though there is nothing particularly new or startling
about them. They do, however, tend to show how surprisingly well the
Persian walnut trees can withstand severe cold if it occurs after they
have once gone into dormancy.

Generally speaking, the winter injury to walnuts has been spotty. No
areas of great size have been either free of injury or severely injured.
Usually, where a difference in severity of damage is found between areas
close together, some reason for the difference can be found, but it is
not always evident on the surface.

Injury to Walnuts

With the possible exception of southern Oregon, it is safe to say that
100 percent of the walnut trees in Oregon and Washington suffered some
twig injury as a result of last winter's cold. In many cases the
subsequent dieback of the twigs may extend only a few inches, but
sometimes the injury involves not only the past season's growth but that
of three or even four years back.

As might well be expected, this twig injury of necessity has meant the
loss of many terminal and lateral buds which bear the female flowers; so
for that reason, if for no other, this twig injury has assumed serious
aspects.

In many cases the catkins were severely injured even where there was
little or no twig injury. The catkins of the Persian walnut seem to be
extremely sensitive to cold. Many Persian walnut trees in Oregon this
year failed to produce any catkins at all. Some produced very few normal
catkins, but some half-developed and deformed catkins. An examination of
these partially injured catkins, however, revealed the fact that they
did produce some pollen. It will always remain a mystery to me how as
many walnuts were pollinated and set as there were, with the scant crop
of catkins.

In practically every orchard examined, where the temperature got as low
as minus 10 degrees F., the pith cells were blackened. This is not
uncommon in other tree crops following severe winter injury. Fairly good
peach crops have been borne in Georgia on trees that had the pith cells
completely blackened.

In the case of walnuts this year, many growers were considerably worried
by the fact that even the wood tissue outside the pith region was black