The Republican. [volume] (Oakland, Md.) 1877-current, 1890-09-05
FARM AND GARDEN.
CANADA THlSTLES.

prospects OF Thelr destruction by NAT
ural Enemy. the Rust.
The Canada thistle is Synonymous
with all that is evil. 1t steals its way
into the richest soil by having the wind
carry the minute seeds, or gains a still
better entrance unobserved in the grass
seed for the coming meadow. Whom
once established it is with great diff
Guilty that its deep, wide-reaching roots
can be extracted or otherwise killed.
The spinose forage of the pest is not
relished by live stock and is a severe
test upon the patience and morals of the
person who must needs work among it's
dry, piercing prickers in the harvest
field.
1t is therefore with much delight that
an enemy is announced upon the dreaded
thistle that may work the downfall of
the vegetable arch-fend in the grass
and grain field. While rusts, smuts,
b1ights, mildews and molds have come
to bring ruin to the grain crops, spoil
the potato field and destroy the fruits of
the vineyard and orchard, the triumph
ant thistle has reared its unmolested
head and spread its prickly foliage to
add insult to injury over wide areas OF
our best farmland. However, it has
not proved itself proof against the
whole host of fungi that prey upon
higher forms of vegetation. Last year
we were pleased to observe that a rust
had fallen upon the thistle and did Sc
we're damage to few plants in the vi
entity of New Brunswick, n. j. Other
observers have occasionally met with
the rust upon the Canada thistle in for
mer years, and in the old country it has
been known for a long time.
One of the most Interesting poinss in
connection with this enemy to the
thistle and friend of man is the fact
that it spreads with considerable ra-
oidity. Last year in some patches of
thistleS not more than one out of fifty
plants was affected, but this season
fully half of the shoots in the same
patches are badly diseased. The rust
lives over the winter in the plant and
shows its presence in the thistle shoot
as soon as the latter has come above the
ground. At the time of writing the
rust can be detected several rods from
the infes ted patch. AS the shoots arise
the diseased ones are more rapid in
their growth; that is, the stems grow
faster but fail to put forth as large
leaves as those stems not affected by
the fungus. The longer, straighter
stems with smaller leaves with all parts
of pale color make it easy to distin'
guish the sick from the healthy plants.
As the season advances the leaves be-
come of rusty brown color upon the
under side, and rapidly shrivel and die
while the almost leafless, withered
stems remain behind with reclining
heads. the picture of distress-to those
who have sympathy with the vile
thistle. The brown or rusty coating to
the under side of the leaves is due to a
vast multitude of spores. These spores
while very small are designed for the
spread of the disease, and when they
fall upon healthy plants induce disease,
and in time the unfortunate plant be-
comes rusted. That the rust spreads
with ease there is no doubt; that it
hibernates in the underground parts of
the host in winter seems beyond ques-
ton.
If, as seems evident, we have
stanch friend in this rust of the thistle,
it becomes US to study its habits and
favor it in our thistle fields, provided it
will not grow upon our crops and spoil
them also. There does not seem to be
any reason to fear that it will harm
other plants than the thistles, and
means for it's propagation upon the
thistle are in order. 1t seems to us
that the best way will be to transplant
diseased roots into fields that are still
free from the pest. If for example,
there is single square rod of rusted
thistles in large field, these plants
could be employed to infect the whole
area. The spores go with the wind,
but it will doubtless facilitate matters
to set out the rusted plant. Something
may be done in this direction at the ex-
pertinent stations. Let us extend the
warm hand of welcome to this rust
enemy of the cursed Canada thistle
American Agriculturist.