Catoctin clarion. [volume] (Mechanicstown, Md.) 1871-1940, 1915-07-15
APPLE BLIGHT HAS PROVEN
MOST SERIOUS.
Little Can Be Done To Save This
Years Fruit, But Precautions
Should Be Taken To Pro-
tect Future CropS.
J. B. S. NORTON,
Maryland Agricultural Experiment


Maryland Agricultural Experiment
Station.
Blight is now prevalent on apple
and pear trees in nearly all parts OF
Maryland. On some apple trees
practically all the fruit has been de-
stroyed. The loss in many orchards
in the State Is very serious.
This disease has been present to
some extent since fruit was first
grown in this country, but some
years becomes worse than usual. 1t
is also found on wild hawthorn, crab
apple, service berry, and on many
similar cultivated shrubs. 1t is very
injurious to ounces,
The blight first appears in the bios
SONS, where the bacteria which cause
it are carried by bees. or sometimes
other insects. The germs multiply
in the nectar Of the flowers, and from
a single such flower, bees may infect
the whole orchard.
The disease spreads downward
from the flowers between the wood
and bark, killing two to ten inches
of the twig day, but later it pro-
grasses more slowly, and in apples
usually dies out on the young twlgS;
but sometimes, and usually in pear,
it keeps extending, killing large
branches, or the whole tree, or form
ing cankers in the bark in which ~
bacteria begin to multiply in the
exuding sap around the cankers, or
sometimes in late infected tWlgs,
This is the source of infection in the
spring.
The blight often goes through short
spurs, or sprouts, or wounds of any
kind, into the body of the tree, even
near or below the ground. Many
trees or large branches are girdled
and die in this way every year.
The most effective treatment con-
sists in cutting ont the diseased
parts. In young orchards and in
nurseries where there is naturally
but little blinght and in old orchards
in seasons when blight is not serious,
but cutting out every blight twig and
canker as soon as possible. giving
special attention to the body and
base of the tree, bad outbreak may
be prevented in following years. 1t
Is also necessary to destroy all blight
In the neighborhood on wild or cul-
tivated trees as the bees may carry
II long distances. Bees are, however,
necessary to pollenate the flowers.
When old bearing trees are badly
infected, winter IS the best time TO
cut out the blight. The cuts on large
branches or in the trunk should be
brushed with a disinfectant and when
dry protected by painting with white
lead in linseed oil. In cutting blight
in the growing season, 1t Is important
to wipe the pruning instrument after
each cut on a cloth or sponge wet
with either carbolic acid, concen-
trated lime-sulphur, per cent.
formalin, or other dsinfectant to
prevent reinfection of the next cut.
Cut twigs several inches below where
the blight shows. as In spring the
germs eXtenu nlucn ldItlleI Al tHal
they show on the outside. Keep
water sprouts and all spurs off the
trunk and main limbs of pear and
susceptible apple varieties so that
one useless blighted spur or sprout
may not girdle and destroy whole
branch Of tree.
Some varieties, such as Yellow
Transparent, Wealthy, York Imperial
and Fall Pippin apple and Bartlett
pear are very susceptible, others like
Keiffer and Winesap are less injured.
1t will be seen from the above that
little can be done now in badly af-
fected orchards to prevent further in
Jury this season, but the community
should organize to prevent the spread
of this serious disease another year.