Newark post., 1915-08-11
SAVING THE SWEET
POTATO CROP
Station Men Study Causes Of
Disease

result of various diseases that an
nually injure the crop in the field
and in storage. This statement is
made in bulletin just issued by
DR.. Thomas F. Manns and DR..
Jacob J. Taubenhaus, plant path
ologists at the Delaware College
Experiment Station, entitled "The
Diseases of the Sweet Potato and
Their Control" The bulletin is
the result of several years of care
full investigation and study by
these two men Of the conditions in
the sweet potato districts of the
State.
The bulletin will be of great
value to every farmer not only in
Delaware but throughout the Del
marvia Peninsula who raises sweet
potatoes, as it makes suggestions
for the control of the diseases that
are causing them heavy losses
yearly, in addition to describing
the diseases itself. The same dis
eases prevail in the sweet potato
districts of Maryland, Virginia,
and New Jersey as we'll as num-
ber of Southern States, so that the
annual loss to the growers in this
country from the diseases that
have been investigated amounts
to millions of dollars annually.
Much of the trouble comes after
the potatoes have been stored and
therefore Drs. Manns and Tauben-
haus made a careful investigation
of the storage houses and make
some suggestions as to solving the
problems and controlling the dis
eases. Much of the storage trou-
BILE, it has been found, comes from
poor ventilation.
In a statement relative to the
losses sustained yearly by the Del
aware rgowers the authors of the
bulletin say:
"The sweet potato industry is an
| important one in the South Allan
tic and Gulf States This, like
most other intensive crops, is beset
! by number of diseases which are
causing enormous losses and in
consequence are materially affect
ing the profits to be made in grow
ing and marketing plant that has
an important bearing upon our ma
tional food supply.
Data obtained in the past few
years indicate that Delaware is
losing annually from field and
storage diseases of the sweet pota-
to fully $l20,OO0. The 1912 crop
was estimated to be 100000 bush
els, worth 68 cents per bushel, or
$4O8,OO0. The 1913 crop was es-
timated at $4,000 bushels worth
60 cents per bushel and valued at
$4O5, 900. Losses are caused by
reduction in crop yield through
diseases carried to the field on the
slips from the seed bed or from in,
fection already in the field. These
field infections reduce the yield ap
proximately 10 per cent and cause
loss of $4,000. Losses in stor
age amount to about 20 per cent OF
the crop, valued at $4,000. The
percentage of loss is probably JUS
, as large in the sweet potato dis
; tricts in Maryland, Virginia, anC
other States that grow large acre
, ages of this valuable vegetable.
These losses are caused by sew
; eral diseases; the principal one
; bing: Black rot, stem wilt, grount
3 rot, also known as "pox" or "pit,
4 white rust, septoria leaf spot, sof
4 rot, charcoal rot and dry rot.
"These have been studied some
? what at length in the seed bed
3 field, storage, house and in tn
4 laboratory"
2 After devoting many pages o
( the bulletin to the symptoms AM
causes of the various diseases AM
3 suggestions as to controlling them
. Drs. Manns and Taubenhaus Civ
3 the following summary as the con
2 clusions they have reached afte
several years. study of the dis
eases of the sweet potato in tn
. field and storage houses of Della
ware:
l. The sweet potato is an in
2 portant crop in Delaware.
2. The success of the sweet pc
8 tato crop depends upon the use o
6 good seed. Seconds should b
9 avoided as much as possible. Sill
seeds, or seeds from cutting
IS every third year, followed by tn
use of primes every two year.
g properly treated with corrosiv
6 sublimate, will insure good results
g The use of seconds" seletce
a prime stock, is satisfactory, prt