Atlanta semi-weekly journal. (Atlanta, Ga.) 1898-1920, 1919-01-28

possess a bitter, disagreeable flavor,
The organism producing black rot
may have carried over In the SOIL
from a previous crop of potatoes, or
may have been brought in on diseased
manure or diseased slips. The disease
may be controlled by crop rotation
seed selection and seed treatment.
Scurf, or soil STAIN is very com
mon disease, but one which results
in little direct damage to the potato.
However, the grade of the potato is
lowered, since scurfy potatoes are
Disseminated against on the market,
and there is tendency for such roots
to become infected with storage rots.
1t is also noticed that scurfy pota-
toes usually show cracks. Such roots
also indicate the effect of dryness
more quickly than healthy potatoes.
Scurf is a discoloration of the sur
face skin of the potato and does not
penetrate the skin proper. The dis.
coloration may take the form of
spots, a nothing of the skin or a
general blackening of the entire po-
tato. The margin of the discolored
area is not distinct and is not sunk
en- Gas in black rot). However, 1t
is often difficult to distinguish
small spots of black rot on badly
scurfed roots, and the best policy
is to dispose of all potatoes so af-
fected. 1t should be remembered
that scurf is not natural" but an
undesirable disease which should be
eliminated.
The organism producing scurf may
have carried over in the soil from
a previous years crop of potatoes
or may be introduced on diseased
manure or diseased slips. The dis
ease may be controlled by crop ro-
tation, seed selection and seed treat
Soft rot is the most common and
most destructive of the storage rots;;
1t may, however, occur in the field
while the potatoes are being dug,
wounded roots. Ordinarily. soft rot
cannot penetrate the healthy, I'M
broken skin. On the surface, soft
rot produces a brownish discolora-
ton with indistinct, Irregular mar
gin Such spots are soft to the
touch, hence the name soft rot.
On the interior there is produced &
watery, brownish decomposed mass,
without decided odor, but with a
rather bitter flavor AS the diseased
elled and hard. From breaks in the
skin the disease produces a black.
mould-like growth, consisting of the
spores (seed) of the organism.
Soft rot occasionally occurs in the
form of shallow ring around the
potato, and is then designated ring
rot" The organism is, however, the
same in the two cases.
The spores of the organism pro-
ducing soft rot are present gener-
ally in the air. The same organism
produces the "black mould" on stale
bread and other foodstuffs.
Blue mould is a storage disease,
| but occasionally occurs in the field
under conditions Of moisture. 1t at
! lacks wounded and bruised potatoes
| in much the same manner as does
soft rot On the surface the rot pro-
| duces an. indistinct, brownish dis
coloration, while the interior, is
| changed to a more or less dry,
| chalky-white mass, somewhat resem-
| bling certain stages of soft rot.
About a wound there is produced a
dense, blue-green mould-like growth
of spores (seed).
The spores of the organism pro-
ducing blue mould are present gem
orally in the air and merely await
favorable conditions to b
growth.