The independent-reporter. [volume] (Skowhegan, Me.) 1909-1955, 1913-08-28
POTATO BLAcKLEG
State Agricultural Department Says
It's Easy to Control

potato disease known as blackleg is
either on the increase in Maine or
its economic Importance is being more
widely recognized The nature and
characteristics Of this disease are be-
coming 50 generally known that ii is
unnecessary to discuss them IN detail.
It is sufficient 10 state that blackleg
is Of a bacterial nature ard rs carried
over from year - year in The seed po-
tatoes used / starts from the base
Of the stem a. lis junction with the
seen piece and works upward pro-
ducing an insy-blaek discolorat.on Of
the stem. The attacked plants are
Of sickly appearance. frequently
d~arfed and usually less spreading
than the healthy ones Al this time
Of the year and a little earlier they
may be readily detected in the fields.
While blaehleg is undesirable and
destructive il Maine fields it is by
no means so serious pest here az
in the South where a large percent
age Of our crop is used for seed.
Southern growers are demanding
seed potatoes free from this disease,
and the man WHO car guarantee his
crop as such and VITO can make good
this guarantee will Be able TO dis
pose Of it al a decided advantage
over his competitor who cannot
The plant pathologist Of this Sta
ton has perfected method by which
the disease may be readily eliminated
from given farm at comparatively
small expense II is based on the
fact that the bacteria which cause the
disease do not live over winter in the
soil in this climate. are carried by the
seed tubers. and are easily killed by
germicides
This method consists Of seed selec-
ton and disinfection Seed tubers
intended for planting are carefully
sorted and all that are decayed. badly
cracked or bruised or in any way
diseased are thrown away The
sound tubers are then disinfected by
soaking TWO hours in a solution com
posed Of one pint Of 81 per cent for
maldehyde in 80 gallons of water In
cutting seed any which show any
blackened rings or discolored areas
are thrown away. II is also better
for each seed cutter to have an extra
knife and a small fruit jar filled with
the diluted formaldehyde solution.
Wherever a potato is cut which ap-
pears diseased the knife in use is
dropped into the jar and the other
used Till another diseased potato is
cut Then this knife is placed in the
jar and the first one used again,
Neither selection nor disinfection
alone appears to be sufficient
This method was tried out sle-
cessfully by several potato growers
in 1911 Very satisfactory results
have also been obtained at Hishmoor
Farm. In 1911 a field Of Irish Cob
blers was planted with purchased
seed. This seed was disinfected but
no attempt was made 10 practice the
rigid selection here recommended.
The resulting crop contained a con-
siderable percentage of plants af-
fected with blaekleg. The seed used
in 1912 was taken from this field and
carefully selected as well as disin-
fected As result not a single dis
eased stalk was observed that year
and none have been seen so far this
season on a field planted with the
1912 crop This and the results Of
the cooperative experiments carried
OUT in 1911 Indicate that blackleg
can be cleaned up from a given farm
or locality in from one TO TWO years
time Moreover # care is taken not
TO rointroduee The disease there need
be no further fear from il on the
farm in question
1t is the custom to recommend that
the seed tubers be disinfected before
cutting There are obviously sew
cral advantages 10 BE- gained if this
is done after cutting In one OF The
cooperative experiments mentioned
this latter practice was followed with
a few barrels OF seed Not only were
they not injured but the plants from
these tubers So treated appeared to
be more vigorous than those in ad-
joining rows where the seed was
either not treated or was disinfected
before cutting
The above experiment with some
variation is being tired this season
at Highmoor Farm. Both Green
Mountain and IRISH Cobbler varieties
were used One part of the seed
was planted without disinfection. an
other disinfeeted with formaldehyde
before cutting third lot after cut
ting and fourth lot was soaked in
formaldehyde both before and after
cutting. To date there is no evi-
donce of injury or delayed germiua-
ton as thu result Of disinfcctiou
after cutting The data is not sutfj-
cient on this point 10 draw final con-
illusions but il is sufficient to suggest