Middlebury register. (Middlebury, Vt.) 1886-1937, 1901-03-29
FARM AND GARDEN.
Potato Scab and Its Prevention.

pertinent StdtlOn: IOtdlo SSop 10 No."
to be a germ disease. IL is 1uneu,
growth on the surface of the potato ana
is propagated by spores. Vast NUMBERS
of these spores are developed In the scao
spots. and as the potatoes dry are scat
tered about ~ fine dust. III TINS uust
finds its wav into the soil, potatoes ralsed
in It will be scabby. Also' II the spores
fall upon clean potatoes ana they oe useu
for seed. the crop will be more OF Tess
scabby. The same disease is Iouhu on
the various kinds of beets and similar
~ not the same disease is found on the
turnip. radish, cabbage and carrot.
When once int oduced, this disease
spreads very rapidly and greatly dam
ages the crop. Lime, ashes, carbonate
of soda, carbonate of potassium, magne-
sia and stable manure of all kinds FAVOR
the development of the scab. Inc 1ol-
lowing fertilizers do not tend to increase
it and may even check it, salt, land plas-
ter, superphosphates, sulphate OF ammo
mia. nitrate of soda, kainit, muriate and
sulphate of potash. Some varieties scab
much worse than others under the same
conditions. Among those subject to the
disease may be named Early Rose, Della
ware, State of Maine, Bristol Beauty,
Burbank. andlPolaris those not so liable
to the scab are Rural New Yorker No. 2,
Sir Walter, Uncle Sam and Enormous.
In general smooth. skinned varieties are
not so liable to the disease as are the
vough-skinned kinds. Some experiments
lead to the conclusion that the germs
may remain in the soil six years and then
attack a crop of potatoes. 1t is very
helpful to pillow under crops OF green
clover, as an acid is developed in the de-
composition of the clover that is detri
mental to the development of the scab
germs.
The only safe way to grow potatoes is
to plant clean seed in non-infected soil.
The bulletin gives several methods of
disinfecting seed potatoes, of which the
following are the most,practicable
CORROSIVE sUBLIMATE TREATMENT.
Corrosive sublimate, or bichloride of
mercury, is white crystalline substance,
resembling salt, which can be bought
from any druggist. TO make the solu-
ton, place one ounce of this chemical in
one gallon of hot water, and after allow
ing 1t to stand ten or twelve hours until
dissolved, dilute with more water to
make seven gallons. This solution
should be made in wooden or eaTthen,
rather than metal, dishes, since 1t cor
rodes metals. The seed potatoes are to
be soaked one and one-half hours in the
solution. The disinfection may be done
at any convenient time previous to plant
inn In ri toI of
this solution for several years we are led
to recommend that the disinfection be
done several weeks before planting, since
it may retard termination somewhat
when used just before planting.
In using this solution it must be re.
membered that it is deadly poisonous to
men and animals if taken internally. 1t
is not poisonous to the skin. however, so
that any one may handle the solution or
the treated seed with impunity. All
tubers soaked in it should be planted,
buried or burned.
Corrosive sublimate costs Is cents an
ounce. Since the same solution can be
used over and over again Indefinitely the
expense for disinfaction other than labor
is but trife. The chief disadvantages
in the use of corrosive sublmate as COM
pared with the next remedy, foTmalin.
are two-fold: first, ITS poisonous nature !;
and second, the difficulty of dissolving it.
FORMALIN SOLUTION.
Formalin is watery liquid. also
known to the trade as formaldehyde
solution. 1t is used with potatoes, at the
rate of eight ounces (one-half pint) of
the commercial fOrmain TO fifteen gal
Ions of water The seed potatoes are
soaked two hours in the solution If this
method is used, it is better, according to
our experiments, to disinfect the seed
not more than few days before plant
ing. Corrosive sublimate and formalin
have in our comparative trials during the
last three years given equally good re-
suits as remedies for the scab. The
chief advantages of formalin are that 1t
is rot poisonous and, being liquid, it Is
easily diluted for use and may be placed
in any kind of a receptacle. 1t is. there
fore, considerably more convenient than
is the corrosive sublimate. Another fact
in favor of the formalin is that it does
not injure the seed tubers or retard their
termination as does the corrosive sub
Innate in some cases. Formalin costs
from forty to fifty cents pound (pin).
1t is therefore little more expensive to
use than Is corrosive sublimate, but the
cost of the chemical is small matter in
either case. One pound of the formalin
costing fifty cents will make thirty gal
Ions of the disinfecting solution. This
can be used to dislnfect fifty bushels of
potatoes, or more If care is taken. Prob
ably this solution will slowly lose
strength upon. standing.so that 1t is desr-
able to keep close cover on the barrel
or other receptacle if it. is to be used re-
peatedly. We have never used the same
solution for immersing more than five or
six successive lots of tubers, although
we do not doubt that with care 1t might
be used for more.
A convenient way to use either of the
a hnuQ &c to