The Mobridge news. [volume] (Mobridge, Walworth Co., S.D.) 190?-1917, 1914-08-21
PLUM POCKETS.


the rest of the plum a cavity is formed
on the interior, hence the name
plum Pockets or plum Bladders."
Plums which were not infected at this
time will not be infected later.
Since this disease is perennial in
the young shoots and since these shoots
are the principal sources of infection.
the prime requisite for controlling the
trouble is to prune out and burn all
infected tWigs and plums. Trees
which were badly infected this year
viii undoubtedly be infected again
mex year if the diseased areas are
not removed. 1t is a question wheth-
er spraying will control this disease
or rot. Several experiment stations
recommend spraying in March with
Bordeaux mixture containing six
pounds Of copper su'phate and six
pounds Of lime to so gallons Of water
or with a concentrated line-sulphur
solution, made at the rate Of 80
pounds Of lime and 100 pounds Of sui
phur to Is gallons OF water. Spraying
1T the South Dakota Experiment Sta
ton just before the blossoms opened
did not check over 10 per cent of the
disease, but, since the greater part of
the infection takes place earlier the
spraying must be done not later than
the Goth of March.
serve as support or brace for the tree.
How are the organisms which are
supposed to be purely parasitic in ma
ture carried over from year TO year,
especially whea they attack only the
fruit foliage? We may spray our trees
to insure q d~isease-free crop of fruit,
but are we really making much head
way when We fight only the results
and not one Of the most primary
causes. The conplste life history OF
many OF our diseases is known and we
know that while one stage in this life
history is parasitic upon the fruit
or foliage OF certain trees we also
know that some of these organisms
have another stage in their life cycle
which is either parasitic or sapro-
phytic on another host as uDon the
leaves or fruits which are allowed to
remain over winter on the ground.
Ihls stage which may be saprophytic
IN nature furnishes spores for the
spring infection. Take our apple
scab, for instance. The leaves which
We're attacked with the disease during
the summer, fall to the ground and
during the late fall or early spring de-
Ve!op saprophytically what is known
as the ascigerous stage, which fur
nishes spores for spring infection. The
am IS true with the brown rot OF
plum. In this case it is the mum
mied or dried up plums which fur.
nlsh spores for at least part of tho
summer infection. Take our apple
rust, for instance. Many orchadists
can not understand why their orchards
are always badly infected with rust.
There are two stages to the life his
tory OF the apple rust. The aecidium
stage occurs upon the apple and the
teleuto stage on the red cedar. Our
remedy and only remedy, so far, is to
cut down he red cedars. Some dis
eases such as the apple blotch, apple
black rot, and the brown rot OF plum
affect young shoots, thus giving the
mycelium OF these diseases an onpor.
tunlty to live over from year to year
III the camblum. In cases where the
orchards are badly infected with
scab, blotch, black rot, and bitter rot.
II is advisable to spray some time be-
fore the buds open with a strong so.
luton, or with concentrated lime.sul-
phur. 1t is alsc to be strongly urged
that such infected twigs, so far as nos.
sible. be removed and burned.
What are we going to do with som,
OF u canker diseases such as tho
bitter rot, block rot, pear or appl
blight, and Illinois apple canker? Il
Is a settled fact that these cankers
serve directly as a supply of spores
for the next years infection and not
only that, for they develop sDores
throughout the summer which snread
the disease at that time. During the
winter the orchard should be gone
over and all cankered and rotted
together with the dead limbs
should be removed and burned. IN
out a canker care must be talk
to see that the limb is removed
from ten to twelve inches below the
infected area. if possible, for the N.Y.
celium of the disease usually meme
trates the wood much farther than ia
shown by the external lesion.
Thus it will readily be see, tina.
order to keep the orchard as free
from disease as possible it H. neces-
above. all to know the. ssa,y4ss-r--
The organisms with which we ara
working aid to fight the cause az
or more than to apply a emedv
after they have made their apnear.
iace. We must keep the orchard iu.
. sanitary condition, we must as far
TcsssSA9 rrcvent infected 3oavps
fru't attacked with such Diseases
apple scab from remaining in the
over winter. and above ali
must remove canksred limbs M
,uyn them.