The true northerner. [volume] (Paw Paw, Mich.) 1855-1920, 1906-04-27
Potato Leaf Blight.

POf0f0 Leaf bHghf.
This disease is widespread and destruc-
tive. 1t is confined to the leaves and
green stems, and appears about the time
that the tubers begin to form, but
may be noticed earlier il the growth of
the plants has been checked in any way.
The first indication of its presence is
the appearance on the leaves of grayish
brown spots, which soon become hard
and brittle. The disease progresses rath-
er slowly, the spots gradually become lar
ger, especially along the edges of the
leaflets. At the end of ten days or two
weeks half of the surface may be brown,
withered and brittle while the rest is a
yellowish green color. Three weeks OF
month may elapse before all the leaves
succumb. The stems in the meantime
remain green, but thew too finally perish
through lack of nourishment. The tu-
bers stop growing almost as soon as the
leaves are attacked and as result the
crop is practically worthless.
Early blight may be held 10 check
by the application of the fungicide Bor.
deaux mixture. This is prepared and APP
piled as follows: Pour into 50-gallon
barrel 20 gallons of clean water; then
weigh out six pounds of crushed blue
stone, or copper sulphate, and after ty-
ing it in a piece of coarse sacking sus-
pend the package just beneath the sur
face of the water by means of string
tied to a stick laid across the top of the
barrel. In another suitable vessel such
as a tue or half barrel, slack four pounds
of fresh lime. Slack .he hme carefully
by pouring on small quantities of water
at a time, the object being to obtain a
smooth, creamy liquid, free from grit.
When the lime is Stacked add sufficient
water to make % gallons. As soon as
the bluestone is dissolved, which will re-
qure an hour or more, pour the lime
milk and bluestone solutions together,
using separate barrel for the purpose,
stirring constantly to effect thorough
mixing. 1t sometimes happens that
sufficient lime is not added, and as a re-
suit the foliage may be injured. To be
certain the mixture is perfectly safe hold
a steel knife blade In it for two or three
minutes, and il the polished surface of
the blade shows copper colored tinge
add more lime, but if it stays bright it
is safe to use. Application of the mix
ture should begin when the plants are
four to six inches high, and should be
repeated at intervals of II to IA days
until five or six treatments have been
made. BY adding eight ounces of Paris
green to each barrel of Bordeaux mix
ture combined fungicide and insecti-
eide is obtained, and this will prevent
the Colorado potato beetle, the flea beetle
and other insects. Before adding Paris
green it should ue mixed with a small
quantity of water, and when a thin paste
is obtained this should be thoroughly
stirred into the barrel of Bordeaux solu-
ton.
The success attending the application
of Bordeaux mixture depends in large
measure upon the thoroughness with
which it is applied. To reach all parts of
the plants above ground with fine
spray requires good force pump and a
suitable nozzle. The knapsack sprayer,
now on sale in nearly every section of
the country, will be found one of the
most useful machines for spraying fields
of three acres or less. For larger plan
tations more powerful machines should
be used. A cheap and serviceable appa-
ratus we'll suited for this work may be
made by mounting good. strong force
pump on barrel and then placing the
barrel and mounted pump in light
wagon. The entire outfit, including bar
rel. pump, hose, nozzles, operator and
boy to drive may be drawn by one horse.
AS the wagon Is drawn slowly between
the rows the man in the wagon may OPP
crate the pump and at the same time
keep the mixture stirred, while two
others on the ground hold the nozzles
and direct the spray over the plants.
The nozzle found to be best suited to
the work is the Vermorel. This is now
offered for sale by pump manufacturers
and dealers in seeds and agricultural i'm
plements 10 various parts of the country.
Where there are only a few plants to
treat, simple devices for the treatment
of the fungicide, such as watering cans,
the syringes used by florists, etc., may be
used.
(Co,1fin,xe1 mort ,yepkl