Pullman herald. [volume] (Pullman, W.T. [Wash.]) 1888-1989, 1920-01-23
WINTER INJURY TO FRUIT TREES
BY Professor Morris

cultural department indicating that
the extreme cold weather of the first
two weeks of December has done a
great deal of harm to many peach
trees and in some localities to cher
~, plum, and apricot trees. The
fact that this weather came during
the early part of the winter is to the
advantage of the trees rather than
against them. The damage that has
been done is undoubtedly much less
than the damage would have been
had the same, or an equally severe
spell of weather come two or three
months later.
The darkening of the cambuin lay
er in the wood is not an indication
that the tissue is killed and rendered
incapable of further growth and de-
velopment. A few bulletins have
been published on methods of treat
ment for trees seriously injured by
winter freezing. Missouri expert
enced winter freeze several years
ago that killed many peach trees and
severely damaged others. Those that
were not killed were pruned in vari-
Gus ways. Some were cut back to
mere stumps of large branches, COM
monty called dehorning, others were
pruned intermediate, between that
and normal pruning, others were
pruned about twice as heavy as a
normal pruning would be, some were
pruned normally, others were left
unpruned. In all of the trials of
such work that l have had opportun-
ity to learn about, the trees that re-
than moderate, pruning came
through in best condition and made
most normal growth in the following
and succeeding years.
In some cases where the cambuin
layer was turned to a brown appar-
entity throughout the entire tree
body, the trees which were moder-
ately pruned made a normal growth
the first season and came approx
mately into normal fruit production
the second year Trees that were
severely cut back although appar-
emily injured no more by the severe
weather than those receiving less
pruning, in many cases failed to
make growth and in other cases
started growing only on one side
and made altogether unsatisfactory
development. This, however, is on
~ what should reasonably expected.
The buds that start from such severe
ly cut back trees develop from the
stored food material in the cambuin
layer and the injured tree is less
capable of starting new growth at
such points than the normal tree.
The time of the pruning is of
small Importance and apparently has
little or no influence over the growth
that is to follow. The best advice
that can be given is for the fruit
grower 10 be rather slow about de-
stroying trees that they think are
killed or sevely III uicd BY the time
growth starts IN the spring these
trees will be more easily distin-
guished from those that are prac-
tically certain to continue growth or
are uninjured The system OF cul-
tiVatlon and treatment to be given
other trees to keep them in normal
vigorous growth and fruit produc-
ton. In all probability th9ra are
some localities which will find later
than the fruit BUDS of their pear and
apple trees have also been serious
ly inJm ed. This may, TO eome OK
tent, modify the type of pruning that
should be practiced. If the prospect
OF crop is entirely destroyed, this
year may be used as an opportunity
to reshape trees that have grown out
of form or out of bounds.
This extreme weather has un.
doubtedly worked to the detriment
of some of the orchard pests, but il
should not be expected to.