Oxford Democrat. [volume] (Paris, Me.) 1833-1933, 1910-02-08
Seed Potatoes and Late Blight.

In q publication of the New York De-
partment Of Agriculture Mr.. F. G..
Stewart of the New York Agricultural
Experiment Station states in part IS
follows:-'Since 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 blight free crop in 1910 no matter
what the weather conditions may be
provided zoe plant only Ne,o York groDn
seed. The man who plants Maine grown
seed next year is to be regarded as
menace to the potato crop Of his neigh
bOrs." Mr.. Stewart 10 q botanist Of
experience and one has the right to ex-
pect that he would use language care
fully and only draw conclusions when he
is sure of his premises. II what Mr..
Stewart writes were true, late blight
could be readily stamped out from any
locality. Unfortunately he Is probably
wrong in his premises. That he is ab-
solutely wrong in his conclusions, Ii
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-
tirsly free from the disease. 1t has
been repeatedly observed in sections
where only locally grown seed 10 used
that for several years late blight might
be apparently entirely absent, then fol-
lowed q season of favorable weather
conditions with the blight and rot ap-
pearing in most destructive profusion.
These conditions 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 iu 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. Apparently the disease
occurs slightly even in years unfavorable
to its development, but is so inconspicu-
Gus in these years as to be overlooked.
On account Of the wonderful ability Of
the fungus which causes the disease to
itself and spread, the disease
soon becomes epidemic when favorable
weather conditions appear, whether
they are experienced in Maine or in Now
York.
The plant pathologist of the Maine
Experiment Station is gen.
erally considered to be one OF the best
informed men in America on potato
particularly the disease in
question. Previous to 1907 there had
been apparently no late blight in Maine
for several years. In the summer OF
1905 he spent considerable time studying
potato diseases in the field and gave q
thorough, careful, personal examination
of very large acreage of the fields
where seed potatoes are grown in Maine.
This diligent search failed to reveal
even q single typical leaf of late blight.
Maine does not import seed, and in 1907
potatoes from this, 80 far as observation
could tell, perfectly clean crop we're
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
section was free from rot and
diligent search failed to disclose any dis
eased leaves. The crop of 1909, planted
from the clean seed Of 1908, was again
affected with blight and subse-
Quent 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 locaii-
ties. So far as known, sound tubers
from fields uhich hare shopn late blight
and rot are no more dangerous as carriers
of the disease than tubers from fields upon
,chich the disease apparently ,cas not pres
ent. 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 pre-
yentative of the disease. Given that,
seed may be taken from any locality
that has vigorous stock. In this con-
nection 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 ma
jority 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, regardless OF
where the seed was produced.
There is in the hands Of the public
printer a circular that explains how to
reduce potato diseases which may be
conveyed by seed tubers, and the conse-
uuent 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,