Evening star. [volume] (Washington, D.C.) 1854-1972, 1901-03-23
CESIRUCTlON3 OF WEEDS
ExPERIMENTING WITH THE USE OF
CHEMICALS.
The Emp1oymeHt of Salt and Distilled
Carbolic Acid Found to
Be Satisfactory.

According to q bulletin recently is
sued by the Department of Agricul-
ture interest Is being shown at a
| number of agricultural experiment sta
lions in the possibility of weed de-
struction by means Of chemicals. 1t is
said that as long ago as 1895 it was found
at the Vermont station that the orange
hawkweed, serious pest in pastures and
meadows, could be destroyed without in
jury to the grass by sowing salt over the
land at the rate of 5000 pounds per acre.
Many experiments have since been conduct
ed at the same station with other chem
icals for the eradication of weeds in walks,
dr1Ves, courts etc. Among the chemicals
tested were salt, copper sulphate, kerosene,
liver of sulphur, carbolic acid, arsenic and
salsoda, arsenate of soda and two CONNER
cial weed killers the active principle of
Wnlch apparently was arsenic. The weeds
Whlch 1t was sought to destroy were plan
talns, dandelion, chicory, ragweed, knot
weed and various grasses. All the chemi-
Gals were applied in solution except the
salt. AS in the case of the hawkweed ex-
per1ments, salt was found efficient in de-
stroy1ng all the weeds when applied dry
and In large quantity.
Distilled CarboIic Acid.
When salt is used for this purpose adj
jacent lawns should be protected against
washing, or they may be injured. Crude
carponc ac1d, one pint In four ptntS of
per square rod, was very efficient. The va
rlous arsenfcal preparations proved valua-
Die as weed destroyers, and choice between
them ., was largely a matter Of expense.
All tnlngS considered, writes the author
Of the bulletin, 1.-THE arsenate of soda and
the carbolic acid solutions proved the most
valuable chemicals for weed destruction
unoer the conditions of these experiments"
Experiments Among Growing Grain.
A series Of experiments in weed destruc-
ton In fields of growing grain has been car
ried on at the North Dakota and other sta
lions, as well as at many places abroad.
Several years ago, in France it was acct
dentally found that a solution of blue vitriol
destroyed charlock, or wild mustard plants.
Actlng upon this, experiments have been
conducted In France, Germany and Eng
land. where charlock Is one of the worst
weeds In grain fields, meadows and pas
lures The method employed Is to spray the
crop with solutions of blue vitriol while the
weeds are young and not too well protected.
While the results obtained are in some re-
spects conflicting, the best results have been
secured when 2 per cent solution Is
sprayed over the field at the rate Of from
forty to sixty gallons per acre. The spray
Ing should be done on a clear, still day, and
before the weeds begin to come into flower.
If rain should fall within twenty-four
hours or the weeds are too old a second
spraying will be necessary. This treatment
has been repeatedly tested without perma-
while such weeds as charlock, shepherd
purse, penny cress, &C., were almost COM
pletely destroyed. No injury followed such
treatment upon young clover growing in the
grain.
At the North Dakota experiment station
a 10 per cent solution! Of blue vitriol was
sprayed over an exceptionally weedy plat
of wheat, the principal weeds being char
lock, wild barley, wild rose, penny cress,
shepherds purse, wild buckwheat, lambs
quarter and great ragweed. The spraying
was made June 1 when the wheat was
three to five inches high, and on August 8
all the weeds except the wild rose and the
older plants Of penny cress were dead
Some of the leaf tips of the wheat had
been slightly burned, but the yield of
grain, it Is said, was considerably larger
than from an equal unsprayed area. On
June 20 part Of an oat field containing
many weeds was sprayed with solution Of
one pound Of copper sulphate to four gal
Ions of water. The oats at the time were
about six inches high, the weeds being
about the same height.
An examination Of the plants was made
on August !, and the treated area was free
Of all weeds except pigeon grass and wild
rose. The oat plants were stalky and well
stooled, while on the untreated area the
plants were weak and failed to STOOL The
crop on the sprayed portion was believed to
be at least one-third more than upon the
unsprayed area. The solution was employ
ed at the rate Of forty gallons per acre.