The San Juan islander. [volume] (Friday Harbor, Wash.) 1898-1914, 1913-08-22
Iron Sulphate Spray for Weed
Eradication.

SuAPAosS spray AO1 W ccu
Eradication.
Oregon Agricultural College, Cor
wallis When properly prepared and
applied, iron sulphate spray not only
destroys weeds of most kinds but
leaves grains or grasses among which
it is growing practically uninjured.
While very effective in preventing
threatened damage to crops from Wig
orously growing weeds, it cannot be
made to take the place of rotations,
CIVILIZATIONS, summer fallow and other
weed preventative measures. Neither
should its use be attempted on weeds
growing in clovers or other broad
leaved crops, as it will destroy them
as well as weeds. Following is the
method Of use, as presented in detail
by Professor II. D. Scudder, agrono-
mist of the Oregon Agricultural COL
lege.
The iron sulphate used as a spray
has been thoroughly tested both by
experiment stations and the manufac-
turers of the sulphate. When properly
prepared and applied it has proved de-
structive to dandelion, yarrow, sorrel,
mustard, lamb s quarters, peppergrass,
bull thistle, wild carrot, pigweed,
shepherds purse and wild daisy. 1t
will not destroy dock, which can be
eradicated only by digging the plant
out or cultivating it to prevent its GO
ing to seed. When used to destroy
dandelions on lawns it will injure the
white clover. And it should be re-
membered that this spray cannot safe
~ be used on weeds growing in any
broad-leaved crop, as it will destroy
the crop as well as the weeds.
s'The value Of this spray as de-
stroyer of weeds lies largely in the
fact that it can be applied and the
weeds killed while they are growing
in the grain crop. The spray will not
destroy grains or grasses because OF
its limited area Of action on their mar
row linear leaves, while it will destroy
the weeds named, largely because OF
its wider area of action on their broad
and succulent leaves.
GAS iron sulphate is a powerful
salt, its action is similar to that Of an
alkali in the soil, causing the leaves
upon which it falls to dry up, turn
brown and die.
'The effectiveness of the spray de.
ponds mainly on four things: First,
it should be applied during dry, sunny
weather, for if rain washes off the
salt within two or three days it is not
effective. Second, it must be applied
with sprayer, which will deliver the
spray forcibly in very fine mist, SO
that the weeds will be covered as COM
pletely as possible. Third, the spray
ing should be done on quiet day.
Fourth, the spray should be applied to
all weeds just before they bloom.
''The spray is prepared by dissolving
100 pounds Of iron sulphate in SO gal
Ions of water. It should be made up
fresh each day in wooden barrels and
the sprayer should be wood, rubber OF
brass. The solution will stain
clothes, and the hands should be pro-
tected by being creased with vase
line.
Ordinarily for mustard in wheat
fields one spraying is sufficient. On
more persistent plants, such as the
dandelion, the spraying must be re-
peated when the plant comes up again.
Flax or wheat may be sprayed without
injury to the crop when from six to
twelve inches in height. Later, the
mustard or other weeds are likely to
be too difficult to reach with the
spray, owing to the shading Of the
grain. =