The Windham County reformer. (Battleboro, Vt.) 1876-1897, 1894-07-13
Potato Blight.

IL Is Jones, DOtanSt or the state agrlcultur.
al experiment station at Burlington, issues
the following bulletin about potato blight =
Our potato vines are attacked by two distinct
blghts. The early blight attacks earlier pota-
toes, spreading slowly in July and August,
causing premature death of vines, but no rot.
The late blight attacks later potatoes in Aug
ust and September, spreading rapidly in warm
moist weather, and is followed by rot. The
early blight is complex trouble, caused by
the attacks of insects as well as fungi. 1t is
already appearing on early potatoes. Being
a complicated disease, it is less perfectly con-
trolled by spraying than is the late blight
Our results last summer showed that it. can
be at least partially checked by Bordeaux
mixture, The late blight and rot is afungous
disease, and Bordeaux mixture properly ap-
piled is an almost perfect remedy. By its use
we have invariably kept our later potatoes
alive through September and have lost but
very few from rot. The result has been that
our yield of later potatoes has been more than
doubled by spraying. Every potato grower
should try it this summer, especially on medi-
um and late potatoes.
The formula for Bordeaux mixture is: Five
pounds of copper sulphate, five pounds lime
Unjust be fresh; not air slackedD, 50gallons of
Il barreD water. Dissolve the copper sui
plate in clean wooden or brass vessels, slack
the lime in another vessel, then dilute with
water to thin whitewash and strain it into
the copper solution. Stir thoroughly and add
water to make about 30 gallons. Chips, Jumps
of lime, etc, in the mixture will clog pump or
nozzles. Therefore, thoroughly clean all
vessels to begin with. Strain, all water and
copper solutions through cheese-cloth, unless
they are perfectly clean, Strain the lime
whitewash through some cOarser cloth or
sieve and throw away all the dregs and
Jumps.
Blue vitriol may be quickly dissolved in
water by heating in brass kettle to the boil
ing point, or by pouring boiling water over it.
The most convenient way we have found,
however, is to dissolve in cold water by put
ting it in coarse sack and suspending this in
the top of tub or barrel Of water. As fast
as the heavy solution forms it settles to the
bottom and fresh water rises. BY using
Il will dissolve in a few hours this way.
To avoid the trouble of weighing, the blue
measured out ive3pOunds equals
two atiarts), and the lime added BY test. This
test consists in pouring few drops OF solt-
in four ounces water) into the mixture. II
there y not enough lime in the mixture this
solution Will at once turn orick-red, but il
enough lime has been added there will be no
change OF color.
Caution. Strong copper sulphate solution
alone will kill the leaves. Freshly Stacked
lime neutralzes the sulphate and prevents this
caustc action. If not sure that the lime is
fresh or good, or that enough is added. the
mixture should be tested as described in four,
or few plants only should be sprayed at first
to test its action.
will not kill the potato bugs. Add Paris green
when needed at the rate of One-half pound to
80 gallons. Remember that Bordeaux mixture
is preventive, not a cure, and the first appli-
cation should be made before the disease APP
pears. The following dates for spraying po-
fatoes are based on our experience at Burling.
ton:
Early potatoes planted April to May o
spray about July l, 10, August l., and again if
needed.
Medium potatoes planted May to May Is
spray about July Is, August l. To- and again
if needed.
Late potatoes planted May Is, or latter
spray about August |, August IA, August %
and again if needed.
The mixture may be put on in any way so
rs to cover the upper surface of all the leaves.
The best way to do this is with force pump
which has good spraying nozzles attached.
but few have these pumps.
Applying with common watering pot or
With pail and broom or wisp of hay takes |
more time and patience, as well as more of the |
but if thoroughly done will give
rood results. In mostlcases where a watering |
,ot is used it will work better if the holes in
he rose are enlarged with an awl. Apply |
will not njure the vines, pro-
iding the mixture has been properly made.