Daily Kennebec journal., 1913-08-30
Problem of Irish
CObbler Potatoes.

In purchasing Irish Cobbler seed pe-
tatees the Maine Agricultural Ex-
pertinent Station has had an experience
similar to that of many southern plant
cfs. Northern grown seed for south
ern planting frequently presents two
serious difficulties which may result in
great financial loss to the purchaser
These are the presence of a consider
arie percentage of tubers of late varie-
ties and the blackleg disease.
To secure profitable returns the
southern grower must he able to dis
rose of his product between the time
the last of the old potatoes from the
north are used up and the time the new
crop from this section comes on the
market in the fall. Hence the popu-
larity with them of the rapid growing
early maturing varieties like the Irish
Cobbler Some southern planters
maintain that ii is frequently nearly
impossible To secure large quantities of
seed of these northern-grown early
varieties without some Of them being
10 to % per cent late varieties like the
Green Mountain. To take advantage
of market conditions it is necessary
to harvest the Irish Cobblers in the
south before maturity. and at a time
when the Green Mountain has just
begun to set tuhers hence these latter
are a total loss. Not only Goes the
planter lose what he paid for the pro-
portion of late variety tubers in his
seed, but he may lose from one-tenth
to ne-fourth of his normal yield.
II -
varieties the southern growers claim
that much of the northern grown seed
is badly infested with blackleg, and
that many fields planted with It show
losses from 10 per cent up to total
failure frcm the attacks of this dis
ease There is no doubt that .blackleg
ia ca rIssd by the seed .anf.i it, is appar-
emily much more destructive in fhe
south than in the north.
II is read dHy understood then how the
presence Of mixtures of late varieties.
and tubers carrying the germs of
blaeltleg may largely reduce if not en-
tirely eliminate the profits of the south
ern grower. He cannot afford TO plant
such seed if he can obtain better
Moreover If he is good business man.
and many of them are. he will pay a
premium for seed potatoes which are
true TO name and reasonably free from
disease. Maine raised potat toes appear
to he peculiarly adapted for southern
planting. and any Maine potato grower
who can guarantee and make good
the guarantee that his seed is true to
name and free from blackleg can
e9 silly retain his seed trade in compe-
t;tion with others in this or any other
northern state. Can he clean up his
seed at n reasonable expense? The
experience of the Maine Agricultural
Experiment Station at Highmoor Farm
indicates that he can.
In the spring of 1911 two lots of Irish
Cobbier seed Were purchased of sup
Insedly reliable dealers. They were
disinfected with formaldehyde but
/ otherwise were handled as they would
| he on the average farm before plant
ing. The resulting crop showed con-
siderable percentage of blackleg, and
| from the color of the blossoms and
the appearance of the plants ii was
apparent that each lot of seed carried
quite a percentage Of Green Mountains.
After blossoming began the field was
| inspected every few days till this period
| vas past and all plants showing white
blossoms We're upro0ted as soon as the
| latter appeared and before tubers had
set to any extent. The percentage OF
| blackleg was so great that 1t did not
| seem feasible to attempt to remove
| all of the diseased plants in the same
! way. However, this is one of the prac-
| tieable means of control If the affected
| plants are uprooted as soon as they
| appear and are destroyed along with
any tubers which may have formed.
| In the spring of 1912 portion of the
| 1911 crop was used for seed. This was
| first carefully racked over and al
tuters which We're badly bruised
| cracked, decayed or showed any evi-
dence of disease whatever, as we'll as
any which from their shape and ap
pearance We're plainly of a different
variety were culed out. The remain
| ing sound tubers were then soaked fol
2 hours i'm a solution of one pint of A.
per cent formaldehyde in 80 gallons
| of water. When cutting any tubei
which was in any way. dIscplQred in
! side was rejected and the knife disin-
fected with formaldehyde before being
Used on another.
The same process was repeated In the
spring of 1912 and again in 1913. AS
the result of careful selection and dis
| infection blaeRleg was entirely elimin-
| ated in one year, for not a stalk sc
affected was found in 1912 nor had
! there been so far in 1913. Very little
| effort was required to remove the
white -blossomed plants in 1912 and none
have been observed in 1913. No ac-
| curate account of the expense of the
extra labor involved was kept but il
could not have been over one or two
cents for each bushel of seed potatoes
produced in any one year. The fact
should not be overlooked that once the
seed is free from other varieties and
from the germs Of blackleg it remains