The Republican journal. [volume] (Belfast, Me.) 1829-current, 1910-02-03
SEED POTATOES AND LATE BLIGHT

In publication of the New York De-
partment of Agriculture Mr.. F. C. Stew
art of the New York Agricultural Elk
pertinent Station states in part as fol
lows: 'sSince there was no late blight
anywhere in the State in 1909 and the
New York potato crop is absolutely free
from late blight rot, we are assured of a
blight free crop in 1910, no matter what
the weather conditions may be, provided
we plant only New York grown seed.
The man who plants Maine grown seed
next year is to be regarded as menace
to the potato crop of his neighbours"
Mr.. Stewart is botanist of experience
and one has the right to expect that he
would use language carefully and only
draw conclusions when he is sure of his
premises. If what Mr.. Stewart writes
were true, late blight could be readily
stamped out from any locality. Unfor-
tunately he is probably wrong in his
premises. That he is absolutely wrong
in his conclusions. is we'll known by every
practical man who has ever given this
question any special observation.
There is no real evidence to show that
any northern State where late blight
ever occurs in epidemic form is ever en-
tirely free from the disease. It has been
repeatedly observed in sections where
only locally grown seed is used that for
several years late blight might be appar-
emily entirely absent, then followed
season of favorable weather conditions
with the blight and rot appearing in
most destructive profusion. These con-
ditions have been observed when a man
as expert as Mr.. Stewart could find no
blight on the foliage of the crop of the
preceding year-the tubers from which
were exclusively used for seed in the
sections under consideration. Neither is
the reverse of the proposition true. A
section may suffer from an epidemic of
blight and rot one season and produce
perfectly healthy crop the following year
and use only home grown seed. Appar-
emily the disease occurs slightly even in
years unfavorable to its development,
but is so inconspicuous in these years as
to be overlooked. On account of the
wonderful ability of the fungus which
causes the disease to propagate itself
and spread, the disease soon becomes
epidemic when favorable weather con-
ditions appear, whether they are expert
enced in Maine or in New York.
The plant pathologist of the Maine
Agricultural Experiment Station is gen.
orally considered to be one of the best
informed men in America on potato dis
eases, particularly the disease in question.
Previous to 1907 there had been appar-
emily no late blight in Maine for several
years. In the summer of 1906 he spent
considerable time studying potato dis
eases in the field and gave thorough,
careful, personal examination of very
large acreage of the fields where seed
potatoes are grown in Maine. This dill
gent search failed to reveal even single
typical leaf of late blight. Maine does
not import seed, and in 1907 potatoes
from this, so far as observation could
tell, perfectly clean crop, were used for
seed. The resulting crop of 1907 was
attacked by one Of the worst outbreaks
of late blight and rot in the history of
potato raising in Maine. In the season
of 1908 seed from these badly infested
fields was used and the potato growing
section was free from rot and diligent
search failed to disclose any diseased
leaves. The crop of 1909, planted from
the clean seed of 1908 was again severely
affected with blight and subsequent rot.
If Mr.. Stewards statements were war
ranted and supported by fact Maine
would gladly have none Of its potatoes
sold or used for seed in 1910. Since they
are not, there is no reason why those
who have in the past looked to Maine for
its strong, vigorous seed should turn to
other less favored localities. So far as
known, sound tubers from fields which
have shown late blight and rot are no
more dangerous as carriers of the dis
ease than tubers from fields upon which
the disease apparently was not present.
In those parts of the country where
weather conditions are favorable to the
spread and propagation of late blight,
thorough, efficient spraying with Bor-
deaux mixture is the only known preven-
tative of the disease. Given that, seed
may be taken from any locality that has
vigorous stock. In this connection it
may be remarked that this discussion
with regard to late blight in Maine does
not concern most of the localities farther
south where the majority Of Maine seed
is shipped. The climatic conditions there
are such that in many Of these localities
late blight seldom if ever appears in such
amount as to cause any damage, regard
less of where the seed was produced.
There is in the hands of the public
printer circular that explains how to
reduce potato diseases which may be
conveyed by seed tubers, and the conse-
quent loss to a minimum. A copy will
be sent on request to any resident of
Maine and to any one who proposes to
use Maine grown seed.
CHAs. D. WOODS, Director.
Orono, Maine.
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