Oxford Democrat. [volume] (Paris, Me.) 1833-1933, 1905-07-18
To Kill Weeds by Chemicals.
BULLETIN OF THE PENNSYLVANIA Ex-
PERTINENT STATION ON THE USE OF
CoPPERAs.

Copperas otherwise called greer
vitriol or ferrous sulphate) has recent!
been extensively advertised as wee'
killer. Its value fer this purpose ha
been very frequently tested during tn
past decade, especially in France, Bel
gium and Great Britain, and also il
Canada. 1t is generally applied in 10 te
20 per cent solution in water (seven t.
nine pounds to barely at the rate o.
forty to fifty gallons an acre, for tht
destruction of charlock, wild mustard
and wild radiSh. To secure good re
suits, the application must be made
while these weeds are still young and
tender, before the time of blooming.
Ii is much less effective on older plants
Instead of using the copperas as a
spray, the farmers of Belgium spread It,
in dry, finely pulverized state, broad
cast on the ground. The quantity thus
applied is from 200 to 800 pounds ar
acre. Ordinary copperas consists Of
rather hard green crystals containing
about IS per cent of water. On expos
ure to air the material gradually loses
water and becomes yellowish or brown
ish white and powdery. If heated
little above the temperature OF boiling
water, the entire mass rapidly whitens
and crumbleS. This freshly heated
finely powdered sulphate is found to be
far superior to the ordinary green crys-
tails for dry application after the Bel
gian method.
1t is not, however, universal weed
killer. 1t is especially effective FOL
wild charlock, wild mustard and wild
radish, but kills wild barley, shepherd
purse, wild buckwheat, ragweed, wall
flower, ground ivy, lambs quarter and
sometimes field poppy, crowfoot anc
cardoon also. Curly dock, black bind
weed, sow thistle, groundsel, comfrey
and egopodium are somewhat injured,
and, more rarely, dandelion and English
daisy, while smooth leaved charlock
corpflower, bent grass, couch grass,
horsetail, chamomile, goosefoot, dead
nettle, speedwell, spurge and thistles,
and often bindweed, field poppies, dan
delon and English daisy, are entirely
uniujured.
The cereal crops are scarcely injured
the edges and tips of the leaves being
sometim slightly Drowned, but usual
ly recovering fully in couple OF weeks
neither are sugar beet, garden peas.
grass, or commonly the legumes seeded
with the grain; sometimes, however
very young clover and lupineS are slight
ly injured; while field peas and beans
are considerably hurt, and vetches, pota-
toes, turnips, rape and flax, seriously
Alfalfa is injured, sometimes killed, by
the dry application.
A sample of "weed killer made by a
New York firm, has recently been re-
ceived by the station. The directions
require its use in the dry state, at the
rate of forty to fifty pounds an acre
broadcast on the plants after strong
dew or slight rain. The claim is no,
made that it will kill all weeds, but that
il will destroy most annual weeds and
iniure those of longer growth. The
presence of small amount of nitrate OF
soda was also claimed to increase the
vigor of growth of the cereal crops upon
which this "weed killer" is applied.
On analysis, the material was found to
be ordinary green vitriol, deprived OF
about two-thirds of its water, and finely
pulverized. No nitrate of soda was
found in this particular sample.
This tweed killer" may be desirable
article if sold at a reasonable price. II
will doubtless prove effective, if used IN
large enough amounts. Belgian ex'
perlence indicates the need for about
five times the quantity recommended in
the manufacturer circular.
Copperas is sold at S2.75 to So hun
dred pounds. One hundred pounds OF
copperas will yield, when suitably heat
ed, about seventy pounds of this finely
divided product.