The Progress., 1894-09-22

of that state on "The Extirpation OF
the Canada Thistle" In this essay
Mr.. Stevens gives the results of care.
ful experiments conducted during the
years 1871 to ls45 in the destruction
OF this plant, ard also an abstract of
every article on the subject that had
appeared in the agricultural journals
and published transactions of the state
up to 1916, summing up his evideLce
in carefully drawn conclusions.
ABSTRACT OF MR. STEVENS ExrERI-
The tbistles experimental on oc-
cupied three kinds of soil, viz T. A
strong clay loan with some slate in
termiXed. q "a reclaimed swamp
with a shallow upper soil Of vegetable
mould, alluvial deposit and clay rest
ing on hardpan' (the timber before
clearing chiefly black ash); and B. "a
rich alluvial creek bottom"
The first soil named was plowed
nine inches deep in April, and the
plowing repeated monthly until Sep
tember, when wheat was sown. The
thistles did not appear after the third
plowing The season was very dry.
On the second soil, three plans were
tried. |. "a plat was burned over by
firing logs upon it until the upper soil
was heated through to the hardpan."
2. 'Another plat was burned over like
the first, and in addition thoroughly
saltcd.' 3. "a plat was soaked down
to the hard pan three times with strong
brine" The thistles were completely
destroyed in all cases.
On the third soil, the roots of the
thistle penetrated to the depth of three
feet, which was down to ground wa
ter. A plat was plowcd deeply six
times during the five months from
Apri, to August. But in September
the thistles were more vigorous than
ever The next year tlis plat was
planted with corn about Nay 20 The
corn was ploN ed and hoed in June,
July and August, n | hoed in SeptCm-
Der, but in October the thistlcs were
more vigorous than any pre-, vious time.
A second plat was burned all
over with log heaps. In a month the
thistles were up through the burned
ground as vigorous as ever. A third
plat was burned over like the second,
and in addition salted thoroughly
three times, hut in month the this
ties tlourishcd as If they had not lcen
mUlested
The next year the three p]ats men
toned above were sown with rcd tor
grass seed, aud wherever the grass be
came established the thistles were
chokel ont.
The red top sward was tried On up
land, but failed to destroy the this.
ties. Timothy and clover were also
tried on the bottom lands, but they
| like wise failed.
The above detailed exterin cuts
were repeated until 1915 with similar
results In experiments made Oh poor
sandy loans, the thistles were readily
killed by plowjng On rich, sandy
loans they were choked out by. SOW Ing
the land to clover.
From a careful study Of his own ant
other experim mis-, Mr.. Stevens de-
duced the following conclusions;
"Whatever will cifectually exclude
the plant from the light and al will
destroy it.. This may be don, LJ
blowing, in some soils, and in others
by close grass sod Flowing, II re-
peated frequently, in soils whore tie
roDt does not descend btyonl th2
reach of the blowing, will, in DIR,
seasons, always destroy the thistle
and often in moist ones In soil!
which are light, deep, rich, friable
and of course permeable to tie air
and are in some measure Away;
moist, plowing will always fail
"Wherever dense sol can bt
formed, the thistle may be destroyed
by seeding, The grasses, wherever
they are adapted to the purpose, will
be found the easiest means Of destruc
ton; although not 30 rapid as plow
ing, hoeing, sailing or burning, where
these latter are available.
"in the uplands, where the soil is o
depth admitting the root to b
reached and atft eted in its hole ex
tent by the plow, hoe, fire or salt th
thistle may be destroyed by thes
means, and they will be found til
most rapid ones.
sin all bottom lands where the roo
descends dep and the soil permits &C
cess OF air, neither the plow, hoe, f'r
nor salt will destroy the thistle; her
the grasses should be applied, and will
be found the best destroyers
Moving will destroy those parts Q
the thistle which have thrown ou
towering stalks; and will not in th
least affect those which have not
Moving should take place when th
plant is in bloom.
Whatever limits the tn orough ~
plication of the means of destructio
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