The Oakley herald. [volume] (Oakley, Idaho) 1908-1961, 1922-04-21

y DR.. b. l.. richards. Associate
Botanist. Experiment station.
Utah Asslculturai College

Utah Asslculturai College
Increased activity in seed potato
production and certificatlon in the
West together with clearer definL
ton Of standards has focused atten-
ton more definitely upon the potato
as product free from disease and
upon seed treatment as an aid In
clean seed production. In the process
OF seed treatment we are concerned
primarily with three diseases Of the
potato plant AL of which are serious
In Utah and throughout the Inter
mountain region: soab, stem canksr,
(Rhizoctonia) and Black leg. The
organisms which cause these diseases
are all tuber borne and as such are
introduced each year into large areas
Of clean land rendering them unfit
for potato production. 1t is definite
ly known that these organisms when
planted with the seed result In de-
creased yield and In the production Of
subers inferior both for the market
and for seed purposes. Further it
must be remembered that the sceb
and the stem canker organisms once
introduced into the soil may live there
indefinitely and seriously damage 9TH
er and succeeding crops.
The disease organisms as they ap-
pear on the surface Of the tubers are
very resistant to the action of chem
icals and rather severe methods are
necessary to destroy them.
For treating seed potatoes two stand
formaIdehyde, one pint to thirty gal
Ions of water, and mersurIc chloride.
ounces to thirty gallons of water.
The formaldehyde treatment is not
effective against Rhizoctonia at ordin
airy temperatures and is therefore not
to be generally recommended. The
mercurio chloride method on the Other
hand when properly applied has given
uniformally good results.
A number of precautions are neces
sary, however, in the application OF
mercuric chloride to the surface of
the potato tuber. In the first place
1t must be recognized that the potato
tuber is living structure and as such
is most resistant to the action of
mercuric chloride when in a dormant
or resting state. With the earliest
signs of sprouting the eyes of the
tubes becomes very liable to injury
from this chemical and considerable
damage may result in treatment at
this particular stage. Early treatment
Is therefore advisable.
Again it has been determined that
damage to the seed may result from
the continued action of mercuric
chloride If the tubers are allowed to
remain wet for a considerable period
after treatment. Rapid drying of ths
tubers will eliminate this danger and
will further add to the effectiveness
of the treatment by depositing a
slight film Of the poison on the sur.
face of the potatoes.
A further protective precaution
must be taken against a too rapid ro-
duction of strength Of the treating so
luton. The surface Of the tubers
rather rapidly absorbs the mercuric
chloride In solution as do also tho
sacks and any other organic materials
that mny be introduced with the seed
Where necessary to use sacks a few
should be previously treated for 2
hours in a solution Of mercuric chlor
ide and then used repeatedly with sue
cessiye lots of potatoes.
Details for treatment are as fol
lows:
SELECT only those tubers for treat
ment which are free from burises.
decayed spots and internal browning.
TREAT UNCUT sEED as early as
possible in the spring. at least ten
days or two weeks before planting.
Avoid the use of sacks in treating.
Keep seed in a clean place and in
sterile sacks after treating and drying.
PROPER STRENGTH, Mercurio
Chloride. 4 ounces to 80 gallons of
water. a.: 10000.
TIME OF TREATMENT. Dormant
seed Y hours. If tubers have started
to sprout and show but little disease
reduce the time. but in all cases soak
the seed for at least u hour. Soak
ing for "a hours In cold water before
treatment will greatly aid in destroy
ing the disease germs.
DRY POTATOES as rapidly as pos
sible after treatment. For early crop.
where convenient green" the tubers
In the sun for few days befor plant
ing.
KEEP UP STRENGTH OF soLU-
TON by adding 3-S ounce Of mercuric
chloride after treating each four
bushels of potatoes treated for one
and one half hours and restore the
volume Of water to it's original 80 gal
ons.
DISCARD SOLUTION after the
third OF fourth treatment where no
chemical is added. 1t is also neces-
sary when chemical is not added to