Smyrna times., 1900-04-11
TREATMENT OF POTATO DISEASES.
Delaware College Experiment Station Sub
mits an Interesting Paper.

A number of inquiries have been
sent to the Station relative to the
treatment of seed potatoes for the pre-
vention of ''scab." 1t has therefore
been thought well to write briefly on
the general treatment of potato dis
ease for the benefit of all concerned.
The chief enemies of the potato are the
scab; the two principal blights of the
top, the so-called carly blight and late
blight; the potato beetle; and the flea
beetle.
All of these enemies can be effec-
lively held in check, and there is no
reason why the farmer shoald suffer
losses from any one or all of them.
Scab originates from the planting of
scabby seed; by planting upon infected
land, i. e., land which has previously
born scabby potatoes; by the use of
barn yard manure from stock which
have been feed on scabby potatoes.
The farmer may endeavor to select
smooth seed, but this in many instan-
ces is nearly impossible since small
specks of scab, especially if the tubers
be dirty, may be overlooked, and even
| this small amount of scab may easily
infect a crop. Hence the only safe
procedure, and it should become un-
form practice, is to disinfect the seed
| previous to planting. This consists i'll
soaking the seed for an hour and
half in a solution of corrosive subli-
mate. This solution is prepared by
dissolving p ounces of corrosive sub
Innate in gallons of hot water in
aUOOden pail. Then when all is dis
solved dilute with cold water to 13 gal
Ions. This solution is a deadly poi
son, and care should be taken that no
stock or persons swallow it, The seed
are soaked whole, then cut up for
planting. 1t is however useless to
treat the seed in this way if it be
planted upon infected soil, i. e., upon
soil that for several years back has
born potatoes which may have been
more or less scabby. Hence land
which is above suspicion should be Sc
lected; the best is that which has been
in sod for a number of years, or at
least land which has not grown pota-
toes four or five years. Lime has a
tendency to increase the amount of
scab; the same is true of stable ma
nure; hence avoid both on potato
lands.
An acid or neutral condition of the
soil is least favorable to the develop
ment of the scab. If green crops, as
crimson clover, be plowed under pre-
paratory to potatoes the fermentation
of the green manure will generate
acids inhibitory to scab. AS fertilizers
use mineral salts such as acid phos-
phate, muriate or potash, kainit or sui
phate of ammonia
Wet, poorly drained lands are favor
able breeding grounds for the scab fun
gus, hence high, dry and we'll drained
lands are preferable.
Very good results have been obtained
treatment of scab, but l am unpre-
pared to say that this is as good as the
use of seed treated with corrosive sub.
Innate planted on clean soil. The cut
seed can be rolled in sulphur previous
to planting, an in addition sulphur can
be busted in the furrow previous to
covering at the rate of $50 pounds to
the acre.
Repeated experiments have shown
that the early and late blights, the po-
tato beetle and the flea beetle can be
controlled by spraying them with the
Bordeaux mixture to every barrel, of
which one-half pound of Paris green is
added.
: The first application should be made
during or Just after the blossoming pc
riod. A second and third is made at
intervals of two weeks. The best noz-
zle is the double Vermorel. Spray
,, thoroughly, or at the rate of $50 gal
! Ions to the acre. Two men and one
; horse can sprang acres day. The
cost of three applications will approx
innate Sc an acre.
Jones, of Vermont, has shown in an
experiment covering nine years an in
crease of 173 bushels of potatoes per
acre as a result of the use of the Bor-
, deaux mixture.
, DEL. COLLEGE AGRICULTURAL Ex-
4 PERTINENT STATION, April 2, 1900