Delaware gazette and state journal. (Wilmington, Del.) 1883-1902, 1900-04-12
THE TREATMENT OF POTATO DISEASES

A number of inquiries have been sent
TO the station relative to the treatment
OF seed potatoes for the prevention Of
"scab. 1t has heretofore been thought
we'll to write briefly on the general
treatment Of potato disease for the
benefit of all concerned. The chief
enemies of the potato are the scab the
two principal blIgbts Of the top, the SOL
called early blight and late blight; the
potato beetle; and the flea beetle.
All of these enemies can be effectively
he'd in check, and there is no reason
why tho farmer should suffer losses
from any one or all of them.
Scah originates from the planting Of
scabby seed; by Planting upon infected
land, /. o., land which has previously
borne scabby potatoes; by the use Of
tarn yard manure from stock which
have been fed or scabhy potatoes.
The farmer may endeavor to select
smooth seed, but this in many instances
is nearly impossible since small specks
o scah, especially il The luhers be
| dirty, may be overlooked, and even
this small amount of scah may easily
infect q crop. Hence the only safe pro.
cedure, and it should become uniform
practice, is TO disinfect the seed pre-
| WINS W LUIS CUuSi5l5 vi
soaking the seed for an hour and a-half
in a solution of corrosive sublimate.
| This solution is prepared by diss Nv.
ing 2i1 ounces of corrosive sublimate
in two pallops of hot water in wooden
| pail. Then when all is dissolved dilute
with cold wattI' to 10 gallons. This
solution is deadly poison, and care
should be taken that no stock or pei sons
swallow it. The seeds are soaked
whole, then cut up for planting. 1t is
however useless to treat tho seed in
this way If it be planted upon injected
soil !. e., upon soil that for several
years back has born potatoes which
may lave been more or less scabby.
Hence land which is above suspicion
shou be selected: the best is that
which has been in sod for number OF
" ars. or at least land which has not
grown potatoes for four or five years.
Lime has tendency IT, increase the
amount of scab the same is tn ue Of
srable manure. hence avoid both on
potato lands.
Al acid or neutral condition of the
soil is least favorable to the develop
mant of the scab. II green crops. az
crimson clover, be plowed under pre-
paratory to potatoes the fermentation Of
he green manure will generate acids
inhibitory to scab. As fertilizers use
mineral salts such as acid phosphate,
muriate of potash, kainit or sulphate Of
ammonia
Wet, poorly drained lands are favor.
able breeding grounds for the scat
fungus, hence high, dry and well
drained lands are preferable.
Very good results have been obtained
by the use Of powdered sulphur in the
treatment of scah, hut / am unprepareo
to say that this is as good as the use
of seed treated with corrosive subj
mate planted on clean soil. The cu
seed can be rolled in sulphur previous
can be busted in the furrow previous Il
covering at the rate of $50 pounds L
! the acre.
Repeated experiments have showr
that the early and late bights, the pc
, taIo beetle and the flea beetle can b.
, controlled by spraying with the Dor
/ deaux mixture to every barrel, OF which
! one-half pound of paris green i:
= added.
+ The first application should be mad
, during or just after the blossominl
period. A second and third is mad
at intervals of two weeks. The hes
:. nozzle is the double Nermorel. Spl a,
thoroughly, or at the rate of $50 gallon
!, to the acre. Two men and one hors
a can spray five acres day. The cost o
three applications will approximate s
an acre.
Jones, of Vermont, has shown in al
experiment covering nine years I'm in
e crease of 173 bushels Of potatoes pc
e acre as result of the use of the Dor
: deaux mixture.
: Delaware College Agricultural Expert
{ ment Station, April, 1900,