Pullman herald. [volume] (Pullman, W.T. [Wash.]) 1888-1989, 1897-11-20
Brown Rot or Fruit Mould.


known "brown rot" or fruit mould
of the plum, peach and cherry. VIZ
first noticed this disease last Aug
ust In the vicinity of Sumner
Pierce county, where we were In
formed it had caused more or less
damage for six years past. Shortly
afterwards specimens were sent ut
from Olympia and Vancouver, and
writer in an Oregon agricultural
paper states that it has been pres
ent in western Oregon for five or
six years. From this it would APP
pear that the fungus is widely dis
tributed west of the Cascades and
must now be included in the list OF
pests which the fruit grower must
regularly deal with in the raising
of his crops.
The fungus was particularly in
furious during the past season to
the prune crop and our account
deals with it especially as it affects
that crop. though it must not be
forgotten that the same fungus also
lives upon and is capable of doing
serious damage to cherries, peaches
and apricots. In rare cases the
fungus is also found on the grape
and the apple.
Usually the first symptoms to at
tract attt ntlon are the numerous
grayish white pustules that appear
on the surface of the attacked fruit.
These rostules consist of the repro
ductive bodies OF the fungus, which
under the microscope are seen to be
oval in shape and arranged in rows
like a string of beads. They are
called conidia. The fungus be-
comes scattered by these conidia,
being carried by air currents or in
some cases by insects. Under fav-
orable circumstances the conidia
quickly germinate, sending out a
germ tube that will penetrate
healthy fruit and soon cause it to
rot. In the laboratory a single
condium planted on an apple or a
plum will develop so far in "A hours
that new conidia will be produced,
From this it is easy to understand
why the disease spreads so rapidly
in orchards in favorable weather;
sometimes the whole crop being
ruined in a few days time.
FRUIT MUMMIFIEs.
A remarkable feature of this fun
gus is that the attacked fruit usu-
ally "mummifes"-that is becomes
dry and remains hanging to the
trees. 1t is mainly on these mum
mifed" fruits that the fungus passes
the winter and on such fruit the
conidia will be found in abundance
in the spring While the conidia
will terminate almost Immediately
under favorable conditions, they
are, nevertheless, capable of with
standing hardships and will grow
after being kept as long as two
years.
The pustules just described con,
stitute only the reproductive part
of the fungus. In the interior of
the fruit are found innumerable
colorless filaments constituting the
mycelium or vegetable parts of the
fungus.
Besides the fruit the fungus also
attacks the leaves, the flowers and
the twigs. When the flowers are
affected they turn brownish and be-
come rotten, In most cases it is
through the stalk Of the flower that
the fungus enters the twig, where it
sometimes causes serious damage,
especially in the case of peach trees.
The mycelium in the twigs lives
from year to year and with little
doubt the fungus was introduced
into our state in this form by some
farmer who purchased eastern nur-
sery stock.
The disease spreads much more
rapidly in damp weather than in
dry, so that some seasons the dam
age is more serious than in others.
Wet weather about the time the
fruit is ripening is particularly fav-
Orable to the fungus and this may
account in part for the injury it
caused this season.
REMEDIES.
As the fungus passes the winter
mainly on the "mummihed" fruits
it is of prime importance that these
be gathered and burned. This
treatment alone is often sufficient
10 hold the fungus in check, and
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