Daily Kennebec journal. [microfilm reel] (Augusta, Me.) 1870-1975, 1915-10-01
POTATO ROT
The Influence of the
Date of Digging upon
Amount of Decay in
Storage

| Orono. Ne, Sept. 29.-(Special.) 1.-The
large amount of late blight on the foliage
which has occurred on potatoes through
out the State of Maine during the pres
ent season has led to an abnormal
amount of tuber decay except where the
most thorough spraying has been carried
out. particularly in those parts Of the
state which as rule suffer least from
this disease. In some instances where
no spraying with Bordeaux mixture was
done or where the work, for one reason
or another, was imperfectly carried out
the potato fields now show a very high
percentage of infected tubers AS re-
suit the Maine Agricultural Experiment
station has received numerous inquiries
whether it would be wise to dig the crop
as soon as the rot begins to show in the
field or wait until later
Some years ago the Director of this
Station carried out some experiments to
determine the influence of the date of
digging upon the development of rot.
g
sisted in conducting similar experiments
IN the -neghboring state of Vermont
where climatic and soil conditions are
very similar.
In Maine nine different varieties were
used in the experiment. but for the sake
OF comparison four early and four late
varieties were Included in the tabulated
summary of results. Tubers from botn
sprayed and unsprayed plots were used,
but since no contradictory data were OBJ
tanned from the former only the latter
are considered here. Equal sized plots
| were harvested on September S and on
october T. AS soon as dug the potatoes
were put in bags, placed in a cool dry
cellar. The very last of December and
early in January the tubers from each
lot were carefully sorted and any which
showed even the slightest signs of incip-
lent decay were rejected. The number of
pounds of potatoes from each plot which
were apparently sound at the date of
harvest, the number of pounds of sound
potatoes found about January /, and the
percentage of tubers which had re-
manned sound were recorded The last
mentioned figures present in concise form
the lesson learned from these expert
ments.
The average of the four early variet,e.
gave. on January /, 80 per cent. sound
for those dug on September and Sc per
cent. sound for those dug on October !.
For the four later varieties these figures
were as and 81 per cent. respectively.
The combined results for both the early
and later varieties taken together showed
that on January ! only 43 per cent OF
the early dug potatoes remained sound
while IS per cent. of those harvested
later were in perfect condition
From the standpoint Of the practical
farmer these figures are still more strik-
ing if the percentages are calculated on
a different basis. Those given represent
the amount of loss between date of dig
ging and January 1, which occurred with
potatoes which were apparently sound
when harvested. Obviously they cannot
take into consideration any rot which
occurred in the soil previous to digging,
which might be of considerable amount
in the case of those last dug which gave
the most favorable results in storage.
Do the figures show that the net result
in sound potatoes on January is equally
favorable to later digging? comparison
Of these figures shows that this is most
emphatically the case. On January !
the total weight Of sound potatoes re-
naming from the ear1y-dug early pota-
toes was only about SO per cent of the
quantity OF tubers in like condition still
on hand from an equal sized plot dug on
the later date. A little better showing
was made in the case of the late yarie-
ties but here the net results on January
obtained from the early digging were
only about so per cent. of that secured
from the delayed harvesting.
The experiments at Vermont were car
ried out independently and without any
knowledge of what was being done in
Maine. This makes the uniformity of the
results and the conclusions derived in the
two different states all the more strik-
ing and valuable.
In Vermont the work was carried on
for three successive seasons, under vary
ing conditions each year. One season the
potatoes were dug on four different
dates, another on five and another on six,
at equal intervals from the last of Au-
gust till the last OF September. One sea-
son a single variety on a single farm
was employed, the next two or three
varieties on five different farms, and the
third vorSafinn Grnvvu nm thu