St. Tammany farmer. [volume] (Covington, La.) 1874-current, 1915-12-04
Fall Measures to Control Pear Blight

AuTUsaN ORCHARD WORK AS
gOUIIlN~ BY THE y. 8.
DEPARTMENT.
In the Management Of the orchard.
especially the apple. and pear orch.
ard there IL . period in the autumn
after the fruit 10 gathered, and per-
haps after other crops have been
safely harvested. that 10 most con-
veninent for. doing some Of the care
full work In the control Of certain
diseases and pests. The control OF
peach borers and insect pests and
fall spraying for San Jose scale have
been discussed in = previous article.
There are certain fungous and bac-
terial diseases. particularly pear
blight and apple canker. which are
best worked upon 1T this time. These
diseases are principally controlled by
the eradication methods rather than
by spraying. With ~both' these dis
eases It IL not only . matter OF
convenience but 1t IL . fortunate
thing that some Of the most impor-
tant work Of the season can be &C
complishod 4 the time when 1t is
most convenient. The mild autumn
days before the snow flies or dis
agreeable, rainy, or cold weather
comes gives the very best opportuni-
ty for careful work and close inspec-
ton.
Fear Balght.
Pear blight 10 . bacterial disease
which works mostly in the feshy,
growing, tender parts OF the tree. In
Guiding the blossom clusters, young
twigs, and the bark OF larger branch.
es. and even On the body, collar, and
root system Of the tree. Under GER
tain conditions the bacteria spread
into the wood to . considerable ex-
tent. The disease attacks the pear,
apple, ounce, and other related
fruits Of the pome family. While
the leaves are attacked to some ex-
tent, particularly the leaf stems and
midribs Of the younger leaves. the
main killing Of the foliage results
from the death OF the twigs and
branches on which the leaves are To-
Gated. The dead branches and Other
parts give no evidence to the naked
eye of the cause of their death AM
thus resemble somewhat limbs killel
by fire; houee the name fire bligh
particularly with blight on the apple
is often applied.
How the Tree Is Infected.
The germs get into the tree Il
several ways. First and most I'M
portant 10 the blossom blight. Fit
and other insects carry the germ
from the .gummy exudate on tn
hold-over blight to the openins
blossoms and infect the hectares Q
the flower. Bees and other insect;
carry the germs from blossom t.
blossom and tree to tree and even
to adjacent orchards and spread dis
ease rapidly during the blooming
period. During the present season
pear blight has been particularly
bad, especially the blossom blight on
both pears and apples. The out
break Of 1915 stands olt as one Of
the worst In history, particularly on
account Of the unusual amount of
V4OUDV&0 k8A6 VA &310 oVR4Os
Next in Importance after the bios
som blight. and in some cases the
most serious phase Of the disease. is
the infection Of the tender tips OF
growing twigs. Thousands of these
young twigs may be killed on a
single large apple or pear tree. The
blight may extend from the infec-
tons on the blossoms or from the
twigs down On the larger branches,
thence to the b dy of the tree. The
branches, bodies. and more particu-
larly the collar and even the root
system Of the tree. may be infected
directly BY the germs. The infec-
ton may come from . fruit spur,
water sprout. or even q sprout from
the root or the gems may be intro
duced by punctures by insects, birds,
Implements. or other means. direct
ly into the 1eshys bark, or even may
enter, In certain cases, through
growth cracks. Ordinarily the euti-
Gle Of tho tree protects 1t from the
entrance Of the germs. otherwise
there would be much more destruc-
ton Of trees than actually occurs.
Each Infection, NO matter where
1t occurs. should be looked upon rs
an individual case Of pear blight
The diseases resulting from the va
rious modes Of attack for convent
;ence are given various s1smes. such
a. blossom blight. twig blight. body
blight. collar blight. and root blight
The lower down the tree, as a rule,
the more dangerous il the blight.
The tree may have 4 thousand OF
more twigs and blossoms killed in
the top and not be seriously or per-
manently injured, while . single case
OF body blight Or collar blight may
result in its death. Each injection
is to be looked upon - a definite,
limited. diseased area. The part At
tackled 10 usually destroyed, though