Vermont phÅ“nix. [volume] (Brattleboro, Vt.) 1834-1955, 1917-08-03
POTATO BLIGHT APPEARS.
Agricultural Extension Service of State
University Issues Warning.

The weather conditions of the past
week have been very favorable to the
development to the late blight of the
potato. A careful examination by the
agricultural extension service of the
state university of potato plants from
plots in Burlington has shown the dis
ease on some of the leaves. The dis
ease appears as irregular dead,
shrivelled, brown spots on the edges
or sides of the lower leaves, especially
those leaves in contact with the
soil. The weather conditions at Bur
lington (high temperature and humidi-
ty) have probably been fairly gen
eral throughout the state. A general
late blight infection is therefore to be
feared, and growers of potatoes,
whether on city lots or in fields are
warned of the danger to their crop UNI
less spraying with Bordeau mixture is
carried out soon as possible.
The spray mixture-No better com
pound has been discovered with which
to combat potato diseases than home
made Bordeaux mixture. 1t is made of
copper sulphate (blue vitrioD water
Stacked lime and water. 1t is only q
fungicide and does not kill the Colorado
potato beetle. If combined with Paris
green or arsenate of lead, both insect
and fungas are attacked. Paris green
is quicker in its action than arsenate
of lead, but washes off more readily and
is more costly. Either works well. Both
adhere to the foliage much longer if
applied in connection with the Bor-
deaux mixture. The spray mixture
should be made as follows: Dissolve 30
pounds of copper sulphate in 30
| gallons of water in a wooden vessel by
suspending the crystals in a sack over
night. Stake 30 pounds of lime with wa
ter and add enough more to make
30 gallons. These are the stock solu-
tions They may be prepared Mt the
beginning of the season and will keep
indefinitely, but must not be mixed I'M
til the day they are to be used. On the
day the spraying is to be done, put three
gallons of the blue vitriol solution in
separate container and dilute this to
approximately 20 gallons. Put three
gallons of the lime solution in another
cOntainer and dilute this to 20 gallons.
Then mix the two solutions, stirring
rapidly as they are poured together.
The mixture should be strained through
a sack or piece of cheesecloth to re-
move the lime particles. Stir three
quarter pound of Paris green Cor one
and one-half pounds dry arsenate of
lead) in little water until it forms a
paste and add it to each barrel of the
mixture. Then add water enough to
bring the whole to 80 gallons.
Time of application-The first appli-
cation should be made when the newly
Matched "potato bugs" are seen or the
flower buds appear, usually the first
week in July. The foliage, especially
the lower leaves should be thoroughly
covered. Other applications should be
made at intervals of about two weeks
An application about September l is
especially desirable since late blight
epidemics at this time are usually fol
lowed by destructive potato rots.
Cost of materials-Two barrels to the
acre should be used, costing: Three
pounds of copper sulphate at 1Sc, 54c
one and one-half pounds of Paris green
at 55c, s3c; three Pounds of lime at lie
&c; one application, $1.40; four applica
tions, $3.50.
The results Bordeaux arsenica
spraying, if properly conducted, in
sures the crop against blight an(
beetles. No bank should loan money
on potatoes that are not thus caret
for. The protection against early dealt
from tip-burn and fea-beetle injury viii
repay the cost of the spraying in year!
when no blight occurs.