The Fargo forum and daily republican. [volume] (Fargo, N.D.) 1894-1957, 1918-01-16


p What arc the diseases which
cause such great losses? They can
be roughly. classified on the basis OF
: the part of the plant which they at
tack.
+, /. Leaf diseases:
Late blight
q Early blight.
Tip burn.
2. Vine diseases:
Dry stem rot.
4 Blackleg.
, wit.
3. Tuber diseases:
Due TO parasites:
Common scab.
PoWdery sCab.
Black scuTf.
Tuber rots.
Not due to parasites:
Hollow heart.
Net necrosis.
| Black heart
Running out diseases:
Curly dwarf.
Leaf roll.
Mosaic.
I'm general II may be said that
any spots on the leaves, or prema-
ture drying of the leaves, whiting Of
! the foliage rotting Of the stem, rot
ting Of the tubers either in the field
or in storage, blemishes on the tub
ers or blemishes inside of the tubers
! indicates the presence of diseases.
Any small dwarfed plants in the
| field or plants with the leaves roll
ed are to be suspected of being dis
eased.
Nature and Cause of Potato Diseases
Potato diseases are caused eth
err by parasites, by unfavorabIe con-
ditions, or by some tendency toward
degeneration in the seed stock.
Such diseases as late blight, early
blight, dry stem rot, blacSleg and
tuber rots are caused by parasites.
Such diseases as hollow heart, and
tip burn are not caused by parasites. |
They are caused by unfavorable
soil or weather conditions, or lack
OF adaptation Of a particular variety I
TO the soil and weather conditions |
under which it is growing. For in
stance, tip burn is very likely to oc- |
cur If varieties best adapted to heavy |
soils are planted on light sandy |
soils. and If periods of hot dry
weather follow periods Of cool moist
weather. The running out diseases
represent n tendency Of the seed
stock to degenerate. They can be
detected only in the field. Their or
iginal cause is not known.
What fosters the development of
potato diseases?
Poor cultural practices are re-
sponsible for enabling many dis
eases to start. Potatoes should be
grown on soils to which they are
should be thoroughly Gull
tiVated, and should not be planted on
the same soil year after year. The
reaction Of the soil quite often de-
ternines whether or not n disease is
to become prevalent For instance.
scab develops best in an
soil If the soil is kept acid
by turning under green crops, scab
will not develop to any great eX-
tent.
Weather: Some diseases become
epidemic only under certain weather
They are not caused by
the weather but the weather enables
ables them to spread. Late blight is
worst during wet cool weather, while
early blight is likely to be worst dur
ing hot dry weather.
How do potato diseases persist?
They persist mainly in the soil,
IN or on the seed tubers, in rubbish, {
or in manure from stock which has !
been fed diseased potatoes.
How can potato diseases be con- s
Erolled?
Select seed. For this year all J
farmers should select their seed
carefully. Only sound tubers Of y
size and true to type should !
be selected. Any which show eXter- /
nal blemishes. flesh discOlOra ton in 5
side Of the tuber. or excessive :
of sCab should not be used. :
"Disinfect seed. After the tubers
have been carefully selected and all I
Insound ones or undesirable types !
the potatoes should be /
in mercury bichlorlde, q
four ounces to 30 gallons Of water, T
FOR an hour and a half; or in /
one pint to 30 gallons $
If water, for two hours. s
Plant on clean soil. The potatoes q
should be planted on soil which has D
lot grown a crop Of potatoes for at n
east three years, or better, five v
ears. c
SPRAY with Bordeaux mixture &
3egin spraying the latter part OF D
July or first of. August. Use $3.50
Bordeaux mixture. Spray very
If not convinced that p
praying with Bordeaux mixture i'm b
edition to the poison for bugs pays, Il
Ty it on a five-aCre patch and keep o
.ccurate yields. Of the sprayed por- il
ion Of the field as compared with il
he unsBrayed. p
Begin a seed plot. Select the best a
,otatoes available and plant them a
n a seed plot. Go through them at Il
time and pull out any n
oreign varieties. Pull any weak, b
VARIED hills, any wilted hills. or II
my plants which show excessive b
olling Of the leaves. Remove the fl
ubers from under all such vines all o
o. Leave only the best plants in II
he plot. Harvest the potatoes from q
his plot separately, store them care "
ully and save for seed for next "
ear. 1t pays. W
What Potato Control Means. IL
Does 1t pay to control potato
diseases? ri
During the past four years ex- n