The Yale expositor., 1915-06-10

10 winch the readers aCentlOn may
well be directed.
These exceptions to the general
practices have been brought to light
largely through Investigations carried
on by the Missouri agricultural ex-
pertinent station. They consist pri-
marily in so managing the orchard as
to maintain the trees in active growth
until rather late in the season. This
may be accomplished by continuing
the tillage later than is ordinarily ad-
vised by using a heterogeneous fertiliz-
er, or by heavy pruning, which results
in a vigorous growth of new wood.
Any condition that seriously reduces
the vitality of the tree tends to make
the tree, especially the fruit buds, sus-
ceptible to injury by winter tempera'
lures. The production Of an excessive
crop of fruit is a common cause of de-
pleted vitality. The conclusions of
the Missouri experiment. station ten
tatively summarized are as follows:
Where nitrogen was applied to
peach trees a good crop was produced
and harvested. On plots receiving no
fertilizer there was practically no crop.
There was likewise a failure OF
! peaches in the surrounding region
where no fertilizer was applied. The
cold winter of 1911-12 was disastrous
to peach trees in Missouri. Injury to
peach trees caused by the cold so
weakened their vitality that disease
| like the bacterial shot-hole leaf dis
ease was common. On the plats fertil-
lied with nitrogen there was little bac-
| terial disease. On adjacent unfertil-
| lied plats the injury from this cause
was very great. The trees in the
| plats fortified with nitrogen also re-
covered from winter iujury much more
successfully and quickly than infer
| tilted trees in the sane locality.
The application of phosphorus and
potassium either singly or in combina-
ton did not result in decreased yields.
The results of the Investigations on
| fertilizers for peaches seem to indicate
clearly that a heterogeneous fertilizer or
a method of cultivation and manage
ment which favors a vigorous tree
| growth when combined with pruning,
| spraying, and thinning fruit on over
loaded trees will increase the crop.
| The above treatment tends to make
| them carry their fruit buds through
winter and frosts of spring much more
safely than where an average or weak
| growth only is secured. Our results
seem to disprove the theory that trees
must make their main growth early
in the season and then be checked or
retarded in their growth in August or
| September In order to ripen their
wood before going into winter. In
some experiments at this station
where the trees have been encouraged
to grow vigorously right up until some
of the green leaves froze on the trees,
either by the use Of fertilizer or by Sc
verely pruning back the winter before
or by thinning the fruit, they have
uniformly carried their fruit buds
through the winter much more safely
than with trees that shed their leaves
and ripened their wood early.
A very careful correlation Of these
results with the conditions which are
generally considered essential in the
growth of peach trees in the northern
districts is necessary in order to un-
derstand their significance. There Is
no real conflict or lack OF harmony in
the methods advised for the different
regions, though in the abstract they
may appear to be directly incompati-
BILE.
In the northern districts, the normal
winter is continuously cold and with
out any warm spells OF sufficient dura-
ton to affect the dormancy OF the
trees. It usually remains cold until
winter finally breaks. When It warns
up enough to start the trees into ac-
tivity and cause the buds to swell,
there is comparatively little danger
thereafter OF serious frosts or freezes.
Moreover, the critical factor-the one
which largely governs the manage
ment Of the orchard in the present
connection-is low winter tempera-
Itures which are sufficient to kill the
buds or inJure the trees even when
they are perfectly dormant. To best
meet this low-temperature factor II is
recognized that the trees must be
thoroughly dormant and the current
seasons growth well ripened.
The United States Department Of
Agriculture. Washington, ID. c., will
send interested fruit growers, free OF
charge, its Farmers Bulletin mo 6S2)
on Growing Peaches" which gives In
detail much information on the prun-
ing of trees. renewal Of tops, thinning,
interplanted crops and special prac-
tees