Oxford eagle. (Oxford, Lafayette Co., Miss.) 1876-current, 1922-08-17
TREATMENT OF SEED POTATOES
FOR SCAB.
DIR. L. E. Miles, Plant Pathologist

WITH some pfdDt deSSstSc. lliS ViiC u
these troubles which is encountered
most frequently is the, so-ealled,
Common Scab, caused by microscop-
ic plant, one of the higher bacteria,
Actinomyces scabies. When these or
ganisms once become established in
the soil, it is a difficult matter to
eradicate them, and sometimes COM
plete eradication seems to be impos-
sible. Year after year they take their
Acatinonlyces toll from the profits
of the grower in the form of reduced
Yields and damaged tubers
The soils of the state are hacolH'ng
more and more infected with this d.
sease. The organism causing scab
thrives only in an alkaline soil In an
acid soil the disease is seldom severe
This accounts for the fact thai scab
is more severe after an application
of lime or other alkaline solutions.
among witch may be include ! stahie
manure This fact caused It ID be oe-
lievea for long time that the deseaSe
was the result of unfavorahle weather
or soil conditions. The alkaline ma
terials do not of themselves
cause scab but merely make the soil
favorable medium for the growth OF
the organism. and which does produce
the disease. If the soil is free of SUCH
organism. and clean seed is planted,
the resulting crop should be clean
The most common WAYS of introducing
the scab organism into the soil is the
nlantinp of scabbv seed or the use OF
manure from stock which have been
fed such seed.
Seed treatment will reduce losses
from this desease at only small eX-
pense. If the desease is not yet pres
ent. seed treatment is cheap and sem
sible precaution to take against its IN
PRODUCTION. Nor is the scab the only
desease against which such treatment
is effective, but such troubles as black
leg. and black scurf, which are oftea
the cause of considerable loss, are
also guarded against All of the three
method outlined below have given
satisfactory results.
Corrosive Sublimate Treatment.
Corrosive sublmate (mercu1c chlor-
;de, a ounces
Water ...... 80 gallons
Duration of treatment LIP hours
Hot water should be used to Dissolve
the material AS the solution corrodes
metal. and is thereby decreased in
strength. it must be prepared and used
in wooden containers Since the soih-
ton is a deadly. poison, both. 1t and
tba notatoes. treated in. it should be
kent awav from children and livestock
Since the solution loOses strength rap
idIy. it is necessary to renew 1t from
time to time. This is done by adding
one-half ounce of dissolved corrosive
sublimate after each ten bushels have
been dipped, and bringing back to the
original volume by adding more water
When this has been done four times,
throw away the solution and prepare
a new one The size of the container
To he used will depend upon the
amount of potatoes to be treated
IF a large number of potatoes are to
be dipped, a wooden tank may De
used.
If the quantity is small, barrel
will probably give entire satsfac-
ton.
Formaldehyde Treatment.
Formaldehyde (40 per cent solu-
tion) ........1 pint or PIN
Water ..-.-. - oo
Duration of treatment III 70 hours
Formaldehyde does not lose
strength on standing, but tends TO
grow stronger because the water
evaporates more rapidly than the
formaIdehyde. 1t can be used eight I
mr. ten times without renewal. AFTER
the potatoes have been treated they
should be spread out in thin layer !
50 that by may dry as soon as pos
sible.
Hot Formaldehyde Treatment.
Formaldehyde (40 per cent solu-
tion) plnts
1Uotor 80 gallons
Din potatoes for two minutes at
temperature of 118 degrees-122 de-
prees F. Make certain that the tenn
nerature does not vary below or ABOVE
these Temperatures, since too not so
luton will injure the potatoes, and
Temperature below 118 degrees r.
will not give satisfactory control.
From time to time the solutlon
should be restored to the Original
volume from reserve supply. ouch
replacement will maintain the mi
tiaI strength. This method has
proven very satisfactory, and IS pre-
ferred by many on account OF the
great saving of time.
When the scab organism is present
in quantities in the Soil, the value OF
seed treatment may be greatly les
sened. Here, in order to assure
successful crop, control measures
must be directed against the organ
ism in the soil. These control meas,
ures developed to date are based
largely on changing the reaction OF
such soil from alkaline to acld;
Where the amount of scab is silgnt'
relief may be had by blowing under
a green cover crop. This practice'
4asotiana. with the use OF acId Ter