The Hood River glacier. (Hood River, Or.) 1889-1933, 1918-06-27
SUMNER PRUNING
URGED ON GROWERS
(By Gordon G. Brown

young trees ranging from one 10 nVe
years. This is the period during
which vigorous trees are producing
much wood growth and few fruit
spurs. Recent experiments conduct
ed at the Oregon Experiment Sta
ton show clearly the desirability of
summer pruning between June Is
and July Is. BY this time trees
should have made approximately
two-thirds of their normal season
growth
Anyone will appreciate that II a
good deal of terminal growth which
is pruned off during winter could be
diverted into desirable lateral grow
tn. especially spurs, the grower
would gain in two distinct ways:
first. earlier bearing would be real
lied and, second, at least one years
growth might be gained by the time
trees are five to six years old. This
is exactly what summer pruning has
done. Note again, please, that this
pruning is to be done while growth
is still active early in the season
long before the terminal bud has be-
gun to form
We will assume that We are now
dealing with a two-year-old New.
town; that is TO say tree which
was set in the spring of 1917. We
will assume that by July / or 18th
its growth is approximately 20 inch
es. Keeping in mind proper proper
tion between branches, let us re-
move the upper five inches, leaving
Is inches upon which leaves and
buds are well spaced Granted that
we have a vigorous tree, growth
should Immediately push out at one
or two places near the point where
the cut was made. This secondary
growth should range anywhere from
ten to thirty inches the same sea
son. Result; instead of much use
less terminal growth to be cut off
during the coming winter, we have
additional branches quite similar to
that which would follow next win
ters pruning. However, often times
the only apparent result will be the
further upward growth Of the bud
near the cut. Seemingly, therefore,
nothing has been gained Is this
true? Examination of buds upon a
normal seasons unpruned growth
that is, auxiliary buds mot spur
buds) shows that those borne well
out near the end where they have
had better light and air are larger
and stronger Further examination
shows that these and not those poor
ly novrished buds near the base of
the shoot are the ones which during
the following year form fruit spurs
Obviously, then, winter pruning suf
ficiently heavy to insure proper
structure and relation of limbs will
remove large portion of these de-
sirable buds, potentially spur buds.
What, then, of the summer pruned
shoot? We will call that which re-
mains after the pruning primary
growth and that which later grows
during the same season as second
airy growth. Investigation discloses
the fact that buds formed upon this
secondary growth function in SINH
lar manner to those upper buds up
on the unpruned shoot. The advan.
tage in summer pruning lies in this
fact the total length of the prim-
cry plus secondary growth is on an
average much less than that for the
unpruned shoot, hence the necessity
for heavy winter pruning following
the summer pruning is obvious. it
is also clear that a fewer numuer VI
the desirable upper buds will have
thus been cut off.
What about those buds on the pri-
mary growth? AS pointed out the
upper one or two buds will grow
and form shoots such as just oes-
cribed. The grower has thus gain
ed in tree structure and in freedom
from heavy winter pruning. The
ether auxiliary buds below, under
the stimulus Of summer pruning,
either form spurs the same season
OF during the following season,
whereas they often remain dormant
and never directly produce fruiting
| wood.
Much then, is to be gained from
summer pruning now or little lat
er Trees must be vigorous, how
ever.
In this work there is little differ.
ence between the character or sum
mer pruning and winter pruning ex
cept in degree Of heavy or light cut
| ting Summer pruning will be large
ly a heading back process, while
that of winter pruning following
such practice will be that of thin
ing. Growers are urged to secure
Bulletin l39 of the Oregon Agricultural
College, which goes into this character
of work in detail.
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