Daily Kennebec journal., 1914-03-05
POWdery Scab
OF Potatoes.


Fer many years the plant pathologist
of the Maine Agricultural Experiment
Station has been studying the COM
men seab of the potato, and in this
connection has asked for specimens of
scab to be forwarded in different years
from various parts of the country.
About a year ago two specimens were
received--one from Massachusetts and
the other from Colorado-whieh were
infected with powdery scab. So far as
is known, this was the first intimation
of any powdery scab produced on po-
tatoes grown within the United States.
Powdery seab differs from the ordi-
nary. scab. which is prevalent every
whore that potatoes are grown, in
quite number of ways. The COM
mon scab is caused by a minute fun
gus; the powdery scab by plants of
a different order and larger size, that
are called slime meulds. The ordinary
scab produces a rather eorky appear
ance upon a potato. Powdery scab
grow in fine scales or powder. 0rdi-
nary scab does not penetrate CT seri-
ously injure the tuber below the skin.
Potatoes badly infected with powdery
scab begin TO shrink and will not keep.
While no methods OF eradicating the
ordinary seab from infected lard have
been as vet found it is possible to clean
up affected seed and also by cultural
methods, particularly green manuring,
that will produce somewhat acid con-
ditions in the soil. to reduce the amount
OF the scab upon the crop. At present
no ways of cleaning seed or land from
powdery scab are known.
In the summer of 1919 a single speci-
men of powdery scab was found in a
field in Presque Isle by the plant pa
thologist of the United States Depart
ment of Agriculture. This was imme-
diately sent to the plant patho.ogist of
the Maine Station, and from that time
on a careful watch was kept for the
powdery scab in Maine. 1t was locat-
ed on one farm at Presque Isle and on
inquiry it was found that that seed
came from an original shipment in 1911
to Portland from Ireland. 1t was con-
fdently hoped that this represented all
of the powdery scab in Maine. Powdery
scab, however, was found to be abun-
dant in New Brunswick towns adjoin-
ing Maine, and it could hardly be hop
ed that Maine had entirely escaped
this infection.
About three weeks ago the Minister
of Agriculture of New Brunswick noti-
fed the Department at Washington
that car of potatoes passing through
Canada in bond contained powdery
scab. This led to an investigation and
the plant patholegist of the Maine Sta
ton, a plant pathologist of the United
States Department of Agriculture, and
a representative of the Maine Depart
ment of Agriculture Immediately went
to Aroostook County and began a
search for powdery scab. 1t was at
once found to be more or less preva-
lent in the territory along the st. John
river in the upper end of the county.
The Maine Department of Agriculture
Immediately engaged half dozen peo-
pie to work with them and have made
a preliminary survey of the county.
They have found powdery scab to be
pretty generally distributed as far
south as Presque Isle, and occasionally
on farms as far south as Houlton. The
infection is not great in amount but
because of the infective nature of the
disease it's being SO wide spread is Of
great significance.
Inasmuch as the United States Board
of Horticultural Inspection have clos
ed all European countries from ship
ping potatoes to the, United States on
scab, they viewed with alarm the sit
uation in Maine, as did also the au-
thorities in Maine. A month ago the
Commissioner of Agriculture, the Di-
rector Of the Station, and q represen-
tative of the Horticultural Board from
Washington, and officers Of the Potato
Growers Association, conferred with
for handling the then one known case
of powdery scab. AS other cases have
developed during the investigation the
Governor has been kept informed, with
the result that on Monday, February
2S, this whole subject was considered
at special meeting of the Council.
In the meantime the Horticultural
Board at Washington had appointed a
hearing making it necessary for Maine
to show what reasons, if any, there
were why infested areas should not
be placed under quarantine.
At the hearing before the Council de-
tailed plans whereby the shipping out
of potatoes Of the crop Of 1918 could