The Emmett index. [volume] (Emmett, Idaho) 1893-1925, 1901-05-31
Press Bulletin NO 3
Sent out from the Agricul-
tural Experiment STA
ton at MOSCOW,
BY the Faculty Of the Uni
yersity Of Idaho.
APPLE SCAB,


as Fusicladium dendriticum. The
suores of this fungus remain over
winter on the dead leaves on tree
or ground, on mummied fruit, or on
the buds or limbs of the tree where
they may have found Judgement
When the season is sufficiently adj |
venced to start the buds on the APP |
ple tree, these also germinate, often
upon the opening buds or the more
advanced and tender leaves, AS
soon as termination takes place
delicate mycelial tube is sent out
from the spore, and this soon bur
rows its way through the cuticle OF
leaf or young fruit, the disease IS
established in this place, and
"scab-spot" rapidly forms. On the
leaves this manifests itself in June
and July in light-green puckered
spots, which later in the season
change to a dirty green or black
green as the spores are formed On
The fruit the disease is more appar-
emf. for the scab-spot is of a much
darker color than the skin OF the
nipple. and is surrounded by mar
row white band where the outicle
is ruptured but not yet destroyed.
This disease does not gain entrance
into the pulp Of the fruit, but lives
inst inside the cuticle, sucking up
the Juice of the apple, and causing
hardning at these spots. These
spots are at first nearly round, but
bv the confluence Of several, the
SPOT may become irregular and COW
er half the apple. The injury to the
leaf is accomplished by destroying
it's vitality, its usefulness to the tree
and causing it to drop premature
~. In this way the whole tree may
be defoliated, when the disease Is
bad and in August and September
the very time when a full foliage Is
most necessary, be comparatively
bare and the ripening OF the fruit
be prevented. The effect upon the
tree through this means Is probably
as serious and the loss to the frul
grower as great, as when the frul
itself is attacked, though this loss
since not seen, is generally OVER
looked When the apple is attack
before il is half grown, and whel
the disease is Of a serious type. tn
the fruit stops growing, or become
atrophied, on the side attacked
and when approaching maturity b
comes distorted and cracks open
thus giving a free entrance to th'
moulds or rot-causing fungi. Th
writer has seen whole crops alon
the Potlatch. on American and FL
ridges in the vicinity of Mosco'
which were materially damaged O
in cases rendered unstable throug
this cause alone. 1t is safe to sa
that hardly an orchard an orchar
is now to be found in this countr
which has not the apple-scab IN
mild or serious form within its Dor
ders. 1t is therefore utterly useles
10 delude ourselves with the val
hope that this disease is not goin
TO effect any serious losses in tn
Palouse aud neighboring countriC
The only way to prevent its II
roads is to wage war with it uncea'
ingly. The time will soon COM
if it has not already, when the sue
CEsSFUL fruit-raiser in this distri'
will he he who properly cultivate
and SPRAYS his orchard, and tt
prices of orchard products kept u
10y the failure of the lazy and IL
different orchardist to market h
diseased and worthless crop.
What shall We spray with al
how apply it?
1t has been proved by many 2
periments conducted by static
workers all over the United State
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