The Dalles daily chronicle. [volume] (The Dalles, Or.) 1890-1948, 1891-02-28
fusIcLAoluM pENTRIrleuM.
The Worst Eaemy of the Apple and Pear.
Hnw to Control It.


know that certain varieties of apples and |
pears are often entirely ruined by black
"scabs" forming on the surfaces of the |
fruit, not only spelling its appearance
but dwarfing it as well. Where fruit is
badly attacked it cracks open.
Some varieties have been nearly all
ruined by scab for several years past.
The most notable examples are the white |
winter Pearmain apple and the winter
Nellis pear Whoever has these two
fruits in bearing should know what APP
pie scab is. 1t is also very injurious TO
many other apples. The best apple of all
the Yellow Newtown pippin-is often
seriously injured, also the red June,
Baldwin and EARLY Harvest. Some va
rieties are not injured in the fruit but
the leaves are badly affected. A few
are injured in neither to any noticeable
extent.
Many varieties of pears are no longer
planted, this disease constantly running
them. The winter Nellis, which in for
mer years was planted largely and prof
itably, is no longer of any value. Also
the white Doyenne and many others.
The Bartlett is fast going down the same
grade.
! This is a progressive disease, constantly
spreading and increasing in virulence.
There seems to be no let up to it when
once it enters region. The fruits sus-
ceptible to it are attacked and destroyed
in turn until, if Prof Bailey of Cornell
university, N. Y, be right, it may sweep
the entire apple and pear crops out of
vast region for one season at least. He
attributes the almost complete failure of
! the apple and pear crops of New York
state last season to an abnormal develop
ment and great virulence of scab. If
it Is very abundant and the season Is
right for its development, it attacks the
buds before the flowers open and kills
the fruit at once.
Experiments during the past three or
four years, both here and in the East,
have demonstrated that this most injur-
ious disease can be controlled. If it can
be prevented from doing material injury
to the most susceptible fruits in Eastern
regions where crops had failed for years
on its account, we certainly ought to be
able to control it, even on fruits worst
damaged by it. 1t is very difficult to
control it where summer rains and
heavy dews prevail.
The disease is parasite fungus, or
minute howerless plant that roots in and
feeds among the tissues of living plants.
Such fungi are usually confined as hosts
to one or a few species of plants. This
particular one is supposed to be confined
in its food habits to the species of the
sub genus Pyrus, to which the apple,
pear and several other species belong.
1t propagates from very minute pollen
like bodies which serve the fungi the
same as seeds do Towering plants. These
pass the winter in myriads on the tree,
| CT I'D
to the young fruits by winds, or, when
in the air are carried to the fruit by rain.
Here they terminate and send their
threadlike rootlets through the skin of
the fruit or leaf, into the cells below.
There the true fungus grows and robs
the cells of their contents and the elab-
Grated plant food which in the fruit
stops the growth and multiplication of
cells so far as it penetrates, max
ing depression in the fruit. Event
, ually the fruiting heads of the fungus
burst through the skin of the fruit and
throws millions of spores into the air
to contaminate other fruits and leaves.
: Cryptoganists are not fully agreed that
it is one and the same fungus that at
5 tacks both fruit and leaves. The best
r evidence, however, is that they are ident-
l same remedy destroys both the fruit and
) the leaf scabs. After the spores are
g thrown off the fungus dies-though its
/ spores may lodge on the same fruit and
( further involve it-and the growth in
the fruit below the scab gradually turns
the black fruiting head out, forming the
well known black scab. If the fruit is
largely involved the growth below rup
= lures the hard, dry, dead matter and il
. cracks open transversely, often ruptur
: ing healthy cells on either side. In such
cases we have scab and craking of the
fruit. The spores can only germinats
+ on the surface of the leaf or fruit, ex
Q cept in presence of moisture. Hence il
u dry summers none but the spring crol
a is very troublesome, except quite neal
3 the ocean where fogs and dews prevail
It Unfortunately there is where winter
}. apples find most pears otherwis,
succeed best. Again our spring climat.
IL favors the development of this and SOM
k other destructive fungi.
e The spores of this and many othe
ID fungi cannot germinate in the presenc
es of the salts and sulphates of copper ant
f many of the combinations of sulphur
whose bases are poisonous to the youn,
re germs as they develop. Spraying tn
re- IreeS JUST aslIne DudS Deg1n 20 swell, wit
,e a strong solution of sulphate of coppe
is effective. Take one pound of sulphat
- dissolved in two gallons of water an
a add eight gallons of water; larger quan
:. titles in same proportion. Spray tn
tree thoroughly so that it will dri
and wet the fallen leaves on the ground
ID This will well nigh destroy the seal
er When spraying to kill the apple wor1
10 directly after the blossoms fall if we mi
London purple in the Bordeaux mixtuI