Oxford Democrat. [volume] (Paris, Me.) 1833-1933, 1918-03-26
Spraying Potatoes Pays.

Some potato growers have expressed
the opinion that it does not pay to spray
potatoes for late blight. They claim
that when the weather conditions are
such that the disease is severe, spraying
does not control it sufficiently to give an
increase in yield, also that
in seasons when the attack is light the
increase in yield from spraying is not
sufficient to cover the added cost. Con-
they maintain that spraying is
at any time.
That thorough spraying will control
late blight in seasons Of bad infection
has been proven many times In the past,
particularly In Maine, and most recently
in Aroostook County in 1917. Among
other places in the county this was
shown conclusively at Aro0stook Farm
where extensive experiments were con-
Quoted by the United States Department
of Agriculture In cooperation with the
Maine Agricultural Experiment Station.
In one block where small test plots
sprayed with standard bordeaux mixture
were interspersed with untreated check
plots the average yield on II of the former
was at the rate of 1Sl Q bushels per acre,
while that on an equal number OF un-
treated plots was at the rate or l4S B
bushels per acre. This was an increase
of S7.7 bushels per acre, or more than
20 per cent In favor Of bordeaux mix
ture.
In another similar block the average
weld of s plots sprayed with bordeaux
was st the rate of nearly 237 bushels per
acre. while that of the 4 untreated check
plots In the same block was 174,3 bush-
els. The gain here was 62.5 bushels per
acre or about SO per cent, due to spray.
ing. Six applications were made on oil
the above mentioned sprayed plots.
On these experimental plots spraying
ought to have been started 10 days. or
2 weeks sooner, by the end OF the first
week In July. In spite of this fact the
Yields given above indicate quite plainly
that spraying paid. Moreover, many
persons who saw the plots during the
later part of the season have testified to
the striking differences on sprayed
and unsprayed portions. On all tne
treated plots the spraying was done VIII
A traction sprayer which maintained
good working pressure OF at least iot
pounds per square inch.
Adjoining ono of the 0experimenta
blocks was field where spraying va,
bseun earlier and 8 or 9 applications
were made. 1t was planted with the
aame lot Of the same variety OF SEED
fertilizsd the Same and, except fol
spraying, received similar treatment II
everv respect. The yield on the portion
Of this Geld Immediately adjoining on.
of the unsprayed check plots was 261
bushels per acre. Comparing this with
the averages Of the unsprayed check
nIots mentioned above shows . gain o.
| i93 s and aS bushels per acre respec
tiyely. or over SO and 6S per cent. II
none Of the above figures 10 any sccoun
made of the extra loss resulting iron
tuber rot in storage In the crop pro
ducsd on the unsprayed plots.
1917 was ono Of the worst blight years
IN the history Of Aroostook potato grow
inc. The results cited above show con
ol9sively that, even under the condition
that existed. late blight can be control
led BY . grower who sets out to DO %
lob thoroughly. Moreover, they indl
cate that It can be done at . fair prom
vhen the cost 10 considered In connes
tjon with the value OF the increase
Weld resulting from the treatment
CHAs. d. WOODS, Director, Maine N
pertinent Station.