Ashland tidings. [volume] (Ashland, Or.) 1876-1919, 1915-10-18

and apple scab, which the committee
begs to state has received the en-
dorsement of the best authorities on
the subject in the state of Oregon.
The article is strictly up to date, and
If the directions given are carefully
followed, scab infection will be con-
trolled, and as the threat to the in
dustry is exceedingly serious at the
present time, the committee requests
every orchardist to cut out this arti-
Gle and preserve it for reference and
guidance.
Pear and Apple Scab.
Scab on pear and apple is one of
the worst pests in the Rogue River
valley. If not kept under control it
will prove to be a very serious men
ace to the fruit industry, as has al
ready been demonstrated during the
past season.
Life History.
II is important that every Iruit
grower be familiar with the life his
tory of this disease in order that he
may successfully combat it. lnfec-
tion takes place from two distinct
kind of spores:-first, those which
develop during the spring and sum-
mer in spots on the leaves, fruit and
sometimes twigs; second, those which
develop during the winter inside the
fallen leaves.
At this time of the year the sum
mer spores or conidisospores may be
found in the olve-green spots on
leaves, fruit and in some cases twigs.
The spots produced by the early in
fection will usually appear cracked
and corky, but will still have the
spores around the edges. The spots
produced by later infection will ap-
pear smaller and will probably be en-
tirely covered with spores. These
summer spores, as rule, do not live
through the winter.
Just below each spot, and extend
ing under the surface of the leaf, will
be found a mass of thread-like fila
ments which which are called the
mycelium. At about the time when
the leaves fall, this mycelium begins
to grow throughout the whole inner
tissue of the leaf. From this mycli-
um. and between the two leaf sur
faces, spore fruiting bodies begin to
develop in late fall and early winter.
They do not mature, however, until
spring when the blossom buds begin
to come out.
The spore fruiting bodies are hol-
low, flask shaped, and appear from
the outside like little black pimples,
often so small as to be invisible to the
naked eye. They have small open
ing at the surface of the leaf, which
is protected by spines that surround
it. Inside the spore fruiting bodies
there are many elongate, sack-like
bodies called asci, each of which con-
tains eight winter spores or asco-
spores. When these mature, they
push out through the opening in the
leaf surface and shoot out the spores,
which are carried by the wind and
air currents into the trees. 1t is
these winter spores that cause the
first spring infection.
From the winter spores, then, the
surface spots develop.
These spots soon begin to produce
large numbers of summer spores,
which are blow to other parts of the
trees and continue to cause new in
lection as long as conditions are ia
vorabe. Moist, damp, cloudy wealth
er is especially favorable for the
spread of scab.
Methods of Control.
The first step that should be taken
against scab this fall is to plow un-
Ter the fallen leaves and in this way
prevent the winter spores from get
ing out onto the trees in the spring.
A permanent cover crop grown in an
infested orchard is a serious handicap
n combating the scab in as much as
t prevents the plowing under of the
caves.
In the spring just about the time
hat the tips of the leaves begin to
)ush through the buds, apply lime
sulphur at the rate of l gallon to 8
gallons of water plus black leaf 40,
pint to $50 gallons of the spray, as
/ general cleanup spray.
Just after the cluster buds have
opened, while the leaves are still ex-
and the blossom buds are
till in a compact clump in the CEN
er, spray with lime-sulphur, gallon
o 20 gallons of water.
The next spray should be applied
IS the blossom buds separate in the
luster, but before they have opened.
his is known as the pink spray"
nd is considered the most important
pray for scab. Use lime-sulphur at