The watchman and southron. [volume] (Sumter, S.C.) 1881-1930, 1909-07-07
POINTS ON THE SWEET POTATO
Interesting Bulletin Just Issued n,
Clemson.

Inc Soutn Carolina experiment
station at Clemson College has lust
issued Bulletin No. 146 on Sweet Po-
tato Work in 1908," by T. E. Keitt
chemist Of the station. After giving
a review Of the sweet potato investi-
cation work at the South Carolina
station, and at other stations, the bull
letin makes a full report Of expert
ments conducted here, the objects be-
ing: Cd to show the contents Of fer
mentable carbohydrates and their
utilization as a source Of alcohol; (2)
to give information regarding the VAL
ue Of potatoes as a food stun; CD to
obtain results as to the fertilizing ele-
ments removed from the soil by the
potatoes; (D to show the content Of
water, starch, sugars, and protein at
different stages Of growth; CD to COL
lect data as to the comparative yield
of the various varieties, in case the
| manufacture of starch from potatoes
should assume any proportions.
Some interesting facts about the
sweet potato may be summarized as
follows: Experiments show that the
best distance to plant potatoes is
about eighteen inches apart in rows
three to four feet apart, and have ap-
plication Of potash in the form of
kainit or sulphate, moderate applica-
| ton Of nitrogen in the form Of nitrate
| of soda or. cotton seed meal, and a
small application Of phosphoric acid.
Two good formulas given for a
potato fertilizer are: First, 500 pounds
| kainit, 800 pounds cotton seed meal,
200 pounds 16 per cent acid phos-
| phate; and second, 200 pounds sui
phate of potash, 200 pounds nitrate of
soda, 400 pounds 16 per cent. acid.
The first would cost about s16.50 per
| ton and should be applied at the rate
of 500 to 1900 pounds per acre, be-
| cause of it's low percentage of fertili-
zing elements; the second should cost
about $32 per ton, and should be ap-
piled at the rate of about 500 pounds
per acre, preferably at the time the
slips are put out
Under favorable conditions a yield
| Of about 200 bushels per acre can be
counted on from soil which ordinari-
| ly would produce 20 bushels Of corn.
These potatoes would contain about
1000 pounds of starch besides a good
deal of sugars, which add to their val
| ue as stock feed. The yield Of 200
| bushels per acre would remove about
$3.50 worth of phosphoric acid, nitro
gen and potash.
AS to varieties a comparison of
fourteen varieties with regard to
yield in per cent. starch and in
pounds per acre, shows that the per
cent. ranges from 1876 in the yellow
Nancemond to 1888 in the Shanghor
yam; and that the yield per acre
| ranges from 1927 pounds of starch in
the Arkansas beauty to 4,443 pounds
of starch in the Southern queen, with
the Brazilian as a close second, yield
ing Alas pounds.
Feed stuff analyses show very high
per cent of nitrogen free extract,
which we in the South are short on.
They can be fed to advantage to all
kinds of stock from September / to
January /, after which, if they can be
kept, their value is too great to be
FED to stock profitably Comparison
with other root crops show a decided
advantage in favor of the potato as
stock feed; and comparison of the
vines with clovers, peas, etc, show
that the vines are not so high in pro-
tein. but higher in nitrogen free ex-
tract and other extract. The vines
contain large percentage of fertilizing
elements taken from the soil, but they
can be left on the land or feed to
cattle and the manure returned to
add numus, thus improving the land
in either case.