Milford chronicle. [volume] (Milford, Del.) 1878-1974, 1928-03-16
SWEET POTATO
DISEASE CONTROL

AS a result of the recent survey
which was conducted in the sweet
potato districts in the state by DR..
T. F. Manns, plant pathologist of
/ the University of Delaware, in CO.
operation with Kent County Agent
Russell E. Wilson and Sussex
County Agent c. R. Snyder, some
very interesting facts are being
called to the attention of the grow
ers as to conditions which are re-
| sponsible for certain increases in
the prevalence of black rot and
wilt in the sweet potato crop in
these areas.
OF the several practices which
have a tendency to bring about
these increases of diseases, it has
been found that the continuous
cropping with sweet potatoes with
out proper rotation is one of the
chief causes, as these troubles are
carried from one season to another
in the fields, and many of these
fields are now infected with the
wilt.
Several farm practices such as the
feeding to hogs and other animals
in the barnyard the culled sweet
potatoes which are carrying black
rot, wilt, scurf and other diseases,
will spread these troubles directly
to the fields, and manure produced
in this manner is certain to in
crease the growth of the molds
which cause these diseases and in
turn carry them back on the land.
AS the decayed and infected sweet
potatoes carry these diseases for
several years, the diseased tubers
should never be dumped on land
that is to be planted to this crop, or
fed in the barnyards to become
mixed with the manure which is to
be used on such fields.
The soil in the seed bed is prob
ably responsible for carrying more
disease than all the other sources
combined, for such soil when used
two or three times becomes literal
ly filed with all these diseases. The
soil in the bed, therefore, should he
changed every season if proper
bedding soil can be obtained. In
case new soil is difficult to secure,
however, the old dirt should be
screened to take out large pieces of
infected potatoes, and then treated
with formaldehyde solution con-
sisting of one pint of farmaldehyde
to thirty gallons of water. One
gallon of this solution will treat
about three square feet, and the
bed should be made and drenched at
least ten days before the potatoes
are bedded, as this will allow
sufficient time for the formaldehyde
to disappear. The practice of seed
selection and treatment with cor
rosive sublimate is practically
worthless unless the seed bed soil
is clean and free from disease.
The examination of many sources
of seed seemed to indicate that
black rot, wilt and scurf are pres
ent on most of the tubers, conse-
quently the careful selection Of the
seed potatoes in addition to the
proper seed treatment with either
the corrosive sublimate or any of
the new mercury compounds that
are being recommended for this
purpose will greatly reduce this
disease prevalence. The growing
of slip seed is another very import
ant practice that should be fol-
lowed in the production of sweet
potatoes of a higher quality and
free from these troubles.
DR.. Manns and County Agents |
Wilson and Snyder are cooperating
in placing demonstrations with H. |
A. Kent, near FELTON,, and A. J.
Dolby, near Seaford, and other
growers in the vicinity of Laurel,
to show the value of these practices
in controlling diseases and in
creasing the yields of sweet pota-
toes. Detailed information relative
to the control of these diseases is |
also being sent to all the sweet
potato growers in the two lower
counties Of the state whose names
are on file in the county extension
offices.