Daily Kennebec journal. [microfilm reel] (Augusta, Me.) 1870-1975, 1915-01-27
USE and EFFECT
OF SULPHUR FOR
THE POTATO SCAB
Experiments by the Maine Ex-
perts to Test the Value Of
Sulphur as a Soil Disinfectant
Analysis of the Tests

4 toHliLON SCdD, poWuelE SCdD anu the
rhizoctonia disease of potatoes While
little hope was entertained that a salts
factory material could be found which
would be sufficiently cheap in price TO
allow its use in the necessary quantities
to ensure success the question is OF SO
much importance TO the potato growers
that no possibility of success, 10 matter
/ how remote, can be overlooked.
( The fungicidal properties Of sulphur
are well known Moreover the chemical
/ compounds which would be formed as
the result of the addition of sulphur
would tend TO develop acidity in the soil
which OF itself is unfavoTable TO the
common potato scab organism Expert
ments conducted in New Jersey some
years ago indicated that il was of value.
! at least under some conditions, as a soil
disinfeCtaut for common scab. II can be
purchased in ton or carload jots at a con
siderable less price than the same
amount OF fertilizer. Therefore il
seemed TO be q favorable material with
which TO experiment
The present discussion is limited to
the Use OF sulphur on soil contaminated
with the germs of the common scab and
is not concerned with the use Of sulphur
for other soil-inhabitng potato diseases
Certain greenhouse experiments, al
though necessarily conducted on a small
scale gave some rather interesting re-
suits. sulphur was added 10 10-inch
pots If greenhouse soil. we'll contaminat-
ed with scab germs, at the rate CT 90
pounds per surface acre. This was
mixed only with the soil Immediately
surrounding the seed tuber Stimulating
as far as possible the application in the
. hill ny means of q planter Some If the
pots Of soil were steriIized to make them
comparable to clean land Scabby seed
tubers were planted in this with and
without sulphur. At the same time dis
infected and undisinf ected scahby seed
tuters were planted in other pots OF IN
st"ri!ized soil with and without sulphur
When the seed was scabhy, the soil
not sterilzed, ana no sulphur was used.
100 Per cent OF the crop was scatby. The
addition Of sulphur in the manner dca
'rihed reduced the amount OF scah but
slightly SteriliZed soil and scabhy seel
gave 50 per cent Of scab on the crco.
v bile perfectly clean potatoes were Sc
cured with the same sterilized SOL and
scabby seed where sulphur 1T the rate
Of 800 pounds per acre vas MIXED wita
the soil Immediately surrounding the
SEED piece. apparently this amount o.
sulphur was sufficient when applied in
this manner, 10 prevent the disease from
spreading from the infected seed-piece
10 the crop hut lot enough to mater
iilly reduce il where the soil itsetf was
badly contaminated with the germs OF
rho 6isaaso
Some pots Of fresh greenhouse soil
were planted with scabhy seed tube1s.
lisinfeoted with formaldehyde. with and
without the addition of sulphur 10 the
pots. In this case there was IN average
0: more scab where the sulphur Was
used than without. a reasonable expla-
nation Of the failure Of sulphur 10 pro
duce results, in this instance. and also
in the unsterilized pots OF soil mentioned
above. comes from tie fact that tie
sca5by tubers were found in those parts
OF the pots outside o. The area of soil
into which the sulphur was Introduced.
The chief value Of these greenhouse
experiments lies in the fact that they
were carried oct under control cordi
tons they are far too limited TO admit
of any definite conclusions. They do,
however, suggest certain things of prac-
teal interests, the most important one
Of which comes from the results obtained
where sulphur was used with scabby
seed on clean or sterilized soil. This is
that the practice recently adopted by
some Of our potato growers OF busting
cut seed with or rolling it in. sulphur is
& good one and should be encouraged. II
the seed tubers are first carefully sorted,
then distrfected with corrosive sublimate
or formsldehyde. cut and busted with or
rolled In sulphur. it would seem as if
the danger from the introduction Of com
mon scab into clean land by means of
seed tuhers would be practically elm
mated.
A close analysis of the results of these
greenhouse experiments does not tend
to encourage the view that sulphur can
be used economically TO rid badly infect
ed soils of the germs Of common potato
scah However. in this and in most other
experiments no account OF the later ef-
fects OF sulphur in the soil are taken in
to consideration and It hardly seems
possible that the entire effects are OBJ
tanned the first year. Hence the case
may not be entirely hopeless.
Tield experiments designed TO test
matters Of This kind are not easy to per-
form as II is next to impossible to get
any large body Of land, equally infected
and alike in all other particulars. An
attempt was made to carry on such an
experiment in cooperation with an Aroos-
took county potato grower last season.
Seven hRlf-acre plots were laid off or
one side Of a large field where the land
was said 10 be fairly uniformly infected
with common potato scab. A plot OF
Green Mountains and one Of Irish Cob
blers were treated at the rate of 1000 of
sulphur per acre, narrowed in before
planting These were followed by an
untreated check plot Of equal size and
this by plots Of Cooble-s, side by side
with untreated checks. where 500 and 3oJ
pounds Of sulphur were added respect
lively.
Several factors interviewed which in
fiuenced the accuracy of the results. but
SO far as could be judged the application
Of 800 pounds of sulphur to this land pro-
dueed no appreciable effects in reducing
common scab the present season. The
potatoes from this plot were equally bad
ly incrusted with scab spots as those
produced upon the adjoining checks
practically all of them being unstable
axrant for starch making. Where 500