Gunnison news-champion. [volume] (Gunnison, Colo.) 1905-1932, 1923-04-20
TREAT SEED POTATOES
FOR DISEASE CONTROl

. Agricultural College News Notes.
/ Potato seed disinfection IS one of tho
NOSE effective and practical means OF
reducing black scurf and scab. IL
object Is TO kill the organism in the
! surface Of the tubers and thus prevent
/ infection Of the soil and Of the follow.
| ing crop.
/ Colorado is producing a large
amount of seed potatoes each year.
/ Farmers raising this stock are especi-
ally concerned with black scurf (Rhiz-
octonia), and scab, because it reduces
the production of tubers of high quail
| y. Sections of the state recently
opened to seed potato production
have little or no disease. but all grow
crs thruOut the state and especially
in the older potato sections must prac-
tice the best methods of disease con-
troll in order to maintain the required
standards.
Corrosive sublimate (mercuric chlo-
rlde) has proved the best dislnfect-
ant for controlling black scurf and
scab. The standard solution is pre-
pared according to the following form
ula:
Dissolve four ounces of the chemical
in thirty gallons of water. Since the
chemical dissolves slowly in cold water.
it should first be stirred into about a
gallon of hot water in an earthen or
wooden receptacle After having been
thoroly dissolved, this solution is then
added to the remaining % gallons of
water, which should previously have
been measured and placed in a wooden
barrel. Where a considerable GUAM
tity of potatoes is to be treated, a
wooden or concrete tank may be
used. Avoid using metal containers,
since they corrode very easily.
All potatoes intended for seed pur.
poses should be treated with this dis
infectant before cutting and while the
seed is dormant, that is, before the
tubers have sprouted. This can best
be accomplished by soaking the seed
for from / y to 2 hours in solution
prepared according to the directions
given above.
The solution is rapidly weakened by
use, and consequently it is best to
make up new batch after the same
solution has been used twice in success
sion. However, if this is not convent
ent, the strength of the corrosive sub
| Innate solution can best be maintained
by adding one-half an ounce of the
chemical for every four bushels Of
seed potatoes treated, keeping the
volume of water constant. This All
\ ditional amount is based on the y
to hour treatment.
| Seed potatoes to be treated are to
I be handled mostly in sacks or an open
/ type of crate, but they may also be
handled directly without any container,
especially in small amounts.
The corrosive sublimate treatment
retards the development of the buds
to some extent, so Notwithstanding the
fact that the treatment is usually given
just previous to planting, it is best
done at least ten days before the seed
is cut. In any case, care must be ex-
ercised to prevent the recontamInation
of the seed by keeping the potatoes in
q clean place and handling them ir
clean baskets or sacks 1t must be
remembered that this treatment kills
only the seed" or spores of the black
scurf and scab and does not prevent
these diseases if the potatoes arr
, planted in infected soil. Furthermore
no seed treatment will prevent the
Fusarium wilt or other diseases of thu
interior of the stem or tuber.
CAUTION-Corrosive sublimate j!
a deadly poison if taken internally
] therefore be very careful to keep il
away from young children and ali liv,
stock. Avoid over treatment, eithel
] by too strong a solution or too long ,