The Kennewick courier-reporter. [volume] (Kennewick, Wash.) 1914-1938, 1930-05-22
EARLY AND CAREFUL
THINNING PAYS


The fundamental principal of APP
pie thinning is to improve the quail
ity of the apples remaining on the
trees. As considered in the past,
thinning has had a tendency to in
creases the size of apples left as
well as the percentage of fancy
and extra fancy fruit. We believe
that the tendency on the part of
Washington fruit growers this year
will be to improve the quality to
the highest point possible from the
efficiency standpoint rather than
any letting down of the grades. j
Early thinning has a tendency
first to increase the average size
of the individual apple and thus
decrease the amount of grading
necessary at packing time. Early
thinning also, especially on trees
that are heavily loaded, allows the
tree to overcome the shock of
heavy set of fruit and come back
with set Of strong fruit buds for
another years crop. Early thin
ming also by reducing the number
of apples on the tree increases the
concentration of sugar solution in
the remaining apples which has a
tendency to bring coloring of the
apple at an earlier date. There are
number of other advantages of
thinning which we will just brief
ly mention, such as better shaped
tree, better pest control and reduc-
ed cost of harvesting.
AS the result of work done in
the Wenatchee district by exper-
mental workers recently, the ex-
pertinent station has recommended
the thinning of apples according to
the leaf surface upon the tree. A
careful study of the relationship
between the amount of leaf sur
face and the apples on the tree
showed that a good quality of ap-
pie was secured only when def
mite amount of leaf surface per ap-
pie was available. For the Jona-
than this varied from 80 to 40
leaves per apple; for. the Rome
Beauty, 35 to 45; and for Winesap
and Delicious, 40 to 80. The range
within this variation would de-
pend upon the vigor of the tree.
If tree shows plenty Of vigor
with an abundance of large dark
green leaves, then one Winesap
could be left for every 40 leaves,
but if the tree shows more or less
winter injury with small leaves of
rather light color, then the thin
ming should be done to the point
where only one apple would remain
for every so leaves, and so on for
the other varieties.
Many growers will say that one
can't count leaves when thinning
and yet no one stops to count the
boxes of apples on the tree when
estimating the crop. One can learn
to estimate the number Of leaves as
readily as they can the number of
apples, and we believe that the
first half day spent in thinning
would be well spent if the thinning
boss and those doing the actual
thinning, could stop every half
hour and actually check over the
number of apples left as compared
to the leaf surface on several of
the smaller branches and see just
what kind of a thinning job they
are doing. At all of our thinning
demonstrations held last year, a
branch was thinned to meet the
above standard. When those pres
emit were asked as to how many ap-
piles a branch of the size thinned
should carry, it usually was from
| 10 to Is percent under the num-
Der actually left and yet nearly
everyone felt that the thinning had
been overdone. 1t is for this reason
that we particularly urge that the
growers stop and check their thin
ming operations occasionally when
starting the thinning work this
year.