Audubon Republican. [volume] (Audubon, Iowa) 1894-1925, 1901-04-04
FARM AND GARDEN.
MATTERS OF INTEREST TO
ACRICULTURlSTS
Some Up-to-Date Hints About Cuitiva-
tion of the Soil and Yields Thereof
Horticulture, NitIculture aud Florlcul-
ture.
Black Knot of Plum and Cherry.

Black Knot OF Plum and Cherry.
We have received the following COM
munication from the Indiana Expert
ment Station:
The opinion is quite prevalent among
farmers and many fruit growers, that
the disease known as Black Knot, so
often found upon plum and cherry
trees, is caused by certain insects. 1t
Is true that we may often find upon
cutting open these knots, the larvae
OF certain insects, but 1t Is uniVer-
sally recognized fact among those who
have given the matter careful atten-
ton, that these unsightly, knotty ex-
crescences are due to special fungus
which is almost always confined to the
plum and sour cherry. The insects are
there, because they find these knots
to be good breeding places.
The swellings are first noticed In
early spring, often as coon as growth
begins. They are then Of yellowish
color, but get darker with age. In May
and June, crop of spores, which an
S"SA W oSSuS III hiShci piahSo' oPPS
on the surface of the knots, resem-
bling to the naked eye soft downy
covering. This soon disappears. when
the knots continue to get darker until
winter. when they have the charac-
teristic black color, which makes them
so conspicuous at this season OF the
year. If examined carefully late In
the fall, the surface of the knot Will
be found to be covered with great
many minute pimples or elevations
each one of which is fruit Of the fun
gus in which the winter spores are
contained. These are in turn distrib-
uted later on, and find lodging place
in the crotches of limbs and in the
openings Of the bark, and at the juno
tons of the annual growths. AS these
spores terminate they send their veg
etative organs into the growing It's
sues Of the branch, causing swellings,
which often extend along the branches
four or five inches. These vegetative
tissues do not all die during the win
ter, but some live over. and so new
dl tuc Cu5cS VI lhS oiu SA~S'
may be seen the following year. In
this way the branch may continue to
be infested until finally 1t becomes
completely surrounded, when the cir
culation Is cut of and the branch dies.
When these knots appear upon several
branches at the same time, it Is only
a question Of very short time before
the tree will die.
Treatment: The treatment generally
recommended is to cut of the knots
and burn them, which is good thing
to do. IL it is done before the winter
spores have been distributed. If not,
then some additional treatment will
be necessary. 1t is recommended there
fore, that all knots" be cut OF and
burned during the month february
and in addition to this, spray the trees
with a strong solution of Bordeaux
mixture during the first warm days OF
spring. About the time that buds start.
spray again with the ordinary strength
Bordeaux mixture. This ought to de-
stroy all of the winter spores. Then
in case the branches may have been
already infected the previous year,
they should be sprayed again during
the latter part of May and the first
of June. The young knots may be
destroyed by painting them with chic
ro-naphtholeum or with pure kerosene
oil. Whenever these remedies are
thoroughly applied. there will be no
trouble in controlling the disease. pro-
viding all old, worthless trees have
been cut out and burned and provid-
ing also that the people OF the entire
neighborhood cooperate in this plan
of action. Wherever the Damson plum
is grown this disease is almost sure to
be present; and as it is one Of the
Injurious plant diseases" referred to
in the Indiana inspection law, the
necessity for prompt action on the part
of all owners of infested trees. will be
evident to ALL J. Troop, Horticul-
turist.