The sun. [volume] (New York [N.Y.]) 1833-1916, 1914-11-08
CUCUMBER AND MELON TROUBLES

CUCUMBER AND MELON TROUBLES
Cucumber and melon diseases now
make il necessary to rotate these crops.
DO not plant cucumbers or melons two
years in succession on the same land.
Anthracnoso appears as circular
brown spots from quarter TO "A half
inch I'm diameter on tho leaves Of Gu
cumbcrs and melons. The spots at
first have white centres. but In later
stages become dead and often tear,
leaving holes IN the leaves. ON the
stems anthracnose causes elongated
dlscolored and shrunken areas, which
finally lead to tho death of the plant.
The fruit Is also often spotted. This
disease seems to live over winter In the
dead vines or elsewhere in the fields.
The destruction OF such vines by fire,
with rotation Of crops will be found
helpful.
Downy mildew is a fungus disease
affecting the cucumber plant prime pa ~
through the leaves. 1t attacks the old
lfNN'N III INV NthAIt vi lllt pant uIS l,
and from there progresses outward. the
young leaves at the tips of the branches
living longest II causes first n yell
lowing OF the leaves and family de-
fined angular spots hordered by veins
These become more distinct as the dis
ease progresses. and If the weather IL
moist the undcrslde Of the spots may
be t!nged with purple The disease
-,
in cloudy. humid weather often develops
with the greatest rapidly, so that fields
quickly become az IL scurched 10y lire.
The fungus lives through the winter
N Florida and probably spreads north
ward each summer. There Is also good
evidence that II lives over In green
houses, which may later become CEN
tres of local epidemics The cucum-
bcrs which develop after the disease
has attacked the vines are usually OF
inferior quality. 1t IL exceptional for
this disease TO be severe SO far north
"a Michigan, and 1t may not recur
again for some time. ON the other
hand. 1t il possible that II weather con-
ditions favor It. 1t may he equally
severe another season.
Both downy mildew and anthracnosc
can be controlled By thorough spray
ing with Bordeaux mixture. made up
Of three pounds copper sulphate, SIX
pounds stone lime, and nifty gallons of
water. The copper sulphate should be
dissolved in twenty-five gallons of
water 10y suspcnding it near the sur
face of the liquid in hurlap sack or
other container. The stone lime should
be slaked thoroughly and then diluted
with the other twenty-five gallons Of
water. The two solutions should then
be poured together into third barrel
and thoroughly stirred. II is essential.
however, To begin early. before the dis
case makes It's appearance, to spray
thoroughly. So that the leaves OF the
plants will at all times he covered with
thin film of the bordeaux, and To
spray at close enough intervals 10 that
the new growth will not he subject Ia
fungus attack.
When n cucumber or melon vine sud
denly willis throughout It's length and
dies without aprreciable spotting OF the
leaves tho trouble Is usually caused by
n species or bacteria which enters and
clogs the WITHDRAWING vessels OF tho
stem. This wilt disease is spread by
leaf eating insects and probably also by
soil infection. Rotation of crops is ad
Nised for its control, together with the
addition Of Il fungicide like Paris green
10 the Bordeaux mixture. The Bordeaux
mixture acts as repellent to the in
scots and helps to check the spread OF
wilt. There is experimental evidence
to show the value OF spraying for wilt.
but II should not be expected that this
disease Will be a. fully controlled In
THIS way as the leaf bllghts. II IL also
important to pull and burn diseased
vines as soon as they begin TO wilt. in
order to lessen the spread of the disease.
Pickle spot first appears on the young
cucumber fruits AS small, gray, slightly
sunken spots. These unite into irregu-
lar patches. particularly toward the
Hover end. AZ the spots age thoy
darken to greenlsh black. and a gummy
eXudate often appears. Upon the leaves
where injury Is more rare than upon
tho fruit, the spots are at first watery
and later the leaf willis and rots. The
disease progresses so fast that a plant
may be practically destroyed In few
days. Some experiments have been
made with spraying for the control of
this disease, but the results obtained
do not Justify tho recommendation OF
this means OF control
White pickle affects both the plan,
and fruits Of the cucumber. II causes
the leaves TO turn yellow and ultimately
TO wilt and die. The fruits become light
In color and more or less deformed and
| show light and dark blotches OF green
which often stand out as warts. It at
lacks both young and mature fruits
This In new disease. the cause oil
which is still unknown. and further In.
| vestigations are being made at the Cor