Ladysmith news-budget. [volume] (Ladysmith, Rusk County, Wis.) 1907-1927, 1914-12-18
CUCUMBER DISEASES
REQUIRE ATTENTION


those gof our readers who are rails
ing cucumbers:
There have come to the Depart
ment of Agriculture this year an UNI
usual number of reports and COM
plants of losses to cucumber grow
ers from blights of foliage or fruit,
particularly in certain north-central
States where pickle growing is an
important industry.
These injuries have proved upon in
vestigation to be due to one or an
other of several distinct troubles:
8lighting of the foliage by doWny
mildew or anthracnose, diseases
which have already proved controlla-
BILE by spraying with Bordeaux mix
ture; to the bacterial wilt a disease
the cause of which is known and for
which a remedy is being sought; to
the pickle spot, a disease of sporadic
occurrence and not yet remediable;
or in some cases to a disease of still
unknown nature called white pickle
Those troubles not already worked
out are being investigated by the
State experiment stations in Wiscon-
sin, Michigan, and New York, Or by
the United States Department of Ag-
rculture, and a plan is being formu-
lated Jointly by these institutions to
carry aid to the growers in case of
recurrence of the diseases next year.
1t will have to be proved by ex-
periments whether or not spraying
will be generally profitable. The De-
partment of Agriculture points out to
the farmers that a long rotation OF
crops is an important precautlon,
which should be practiced by all.
There is no evidence that these dis
eases are spread through the seed.
Further details regarding these dis
eases follow:
DoWny mildew-This is a fungus
disease affecting the cucumber plant
principally through the leaves. 1t at
tacks the old leaves in the center
of the plant first, and from there
progresses outward, the young leaves
at the tips of the branches living
longest. 1t causes first yelloWing
of the leaves and family defined ang-
ular spots, bordered by veins. These
become more distinct as the disease
progresses, and if the weather is
moist the underside of the spots may
be tinged with purple. The disease
spreads slowly in bright weather,
but in cloudy, humid weather often
develops with the greatest rapidity,
so that fields quickly become as if
scorched by fire. The fungus lives
through the winter in Florida and
probably spreads northward each
summer There is also good evidence
that it lives over in greenhouses,
which may later become centers OF
local epidemics The cucumbers which
develop after the disease has at
tackled the vines are usually of in
ferior quality. 1t is exceptional for
this disease to be severe so far north
as Michigan, and it may not recur
again for some time. On the other
hand, it is possible that if weather
conditions favor it, it may be equally
severe another season.
Anthracnose.-This disease appears
as circular brown spots from one
fourth to one-half inch in diameter
on the leaves of cucumbers and mel
ons. These spots at first have white
centers, but in the later stages be-
come dead and often tear, leaving
holes in the leaves. They are dis
tinguishable from the angular spots
Of the downy mildew except when
the latter have grown very slowly.
On the stems anthracnose causes
elongated discolored and shrunken
areas, which finally lead to the
death of the plant. The fruit also
is often spotted There is evidence
that this disease lives over winter
| in the dead vines or elsewhere in
the old fields, and the 'estruction
of such vines, together with rota-
ton of crops, is recommended as a
means of prevention.
Spraying the remedy.-Both downy
mildew and anthracnose can be con-
trolled by thorough spraying with
Bordeaux mixture, made up Of 3
pounds copper sulphate, pounds
stone lime, and so gallons Of water
The copper sulphate should be dis
solved in 25 gallons of water by sus-
pending it near the surface of the
| liquid in a burlap sack or other con-
tainer The stone lime should be
slaked thoroughly and then diluted
with the other % gallons of water.
The two solutions should then be
poured together into a third barrel
and thoroughly stirred 1t is essen