Daily Kennebec journal. [microfilm reel] (Augusta, Me.) 1870-1975, 1917-09-07

Maine Agricultural experiment station
at the University Of Maine, and will
be Of particular interest at this time,
owing to the tremendous Importance of
a large potato crop:
The officials of the Maine Agricul-
tural Experiment Station are convinced
that timely and thorough spraying of
potato fields with properly prepared
bordeaux mixture is an efficient means
o. controlling late blight Of the foliage
and the resultant, rot Of the tuber. This
conviction is based upon long series
of practical, comparative tests made
beth in Maine and elsewhere. To date
the season of 1917 has been extremely
favorable for late blight and rot to de-
velop At the same time condition
have been such, in many ways, as to
more or less seriously interfere with
the proper application of the means of
&C ntrol. Blight Or rust as ii is pop
ularly called, has appeared in a de-
structive way on the unsprayed and
less thoroughly sprayed fields over a
considerable portion Of the State. 1t is
even fficult to find field of potatoes
If those sections where as a rule
spraying is most generally practiced
and most efficiently done that does not
show at least some blighted leaves. At
Aroostook Farm where, except on GER
tain experimental fields. fairly thor
ough spraying is followed. an occa SION
al blighted leaf can be found. But
these fields are in marked contrast with
adjoining plots less thoroughly spray
ed, with unSprayed plots and those
upon which certain substitutes for Dor
deaux mixture have been used
If anyone is experiencing partial or
almost entire failure to control late
blight due to the materials or methods
used, now is the time to take account
of stock, determine where the diff
culties lie and plan to avoid repetitons
o. these failures in future years. Some
factors which might influence the re-
are discussed below.
Was the Bordeaux Mixture Properly
Made?
The Station uses and recommends
the $3.50 formula, or pounds of cop
per sulphate (blue vitrioN, of stone
lime 6 to pounds of hydrated lime
is used) and so gallons of water. Dis
solve the copper sulphate and Stake
the lime in separate vessels, dilute each
with half Of the water and then quick
~ and thoroughly mix the two DILUTE
solutions, Immediately before applying.
Do not mix strong solutions together
and do not prepare the mixture any
faster than it is needed for use.
Was the Application Timely?
! The Station directions call for the
/ first application OF the spray when the
plants are 6 to 5 inches tall and sub
seuuent spraying sufficiently often to
protect new growth. This means
spraying as often as once in 10 days.
Wet weather favors the development of
blight Consequently if it is cloudy
and rainy, it may be necessary to
spray every week till the first Of Sep
| t mber or even later. An application
before rain is Of more value than
one made after. The former prevents
| infection and the latter may or may
rot If there is time for the spray to
dry before the rain comes it sticks
better and does more good than is
peculiarly supposed. Bordeaux mix
/
and rot. Late blight starts on the
! lower leaves. Early, thorough spray
ing gives these leaves a protective
coating The rapidly growing plant
soon covers them. prevents washing
! BIZ rain and thus these potential CEN
/ tiers of infection retain their protective
coating throughout the season If
spraying is not begun till the plant has
begun to develop numerous side
branches it is next to impossible to
reach these lower leaves with any or
binary spraying apparatus. If blight
has already started the problem of
control becomes all the more difficult.
Was the Spraying Thoroughly Done?
The Station directions call for high
pressure and sufficient nozzles ar
ranged so as to completely cover the
plants with fine mist like spray. Were
there enough nozZles to the row. and
were the, SO arranged that they cover
Ell the entire row with spray at each
ar plication? Were the nozZles Of a
type and old the pump supply suff1-
cient pressure so that the spray was
dc livered in fine mist that penetrated
forcefully into the interior Of the mass
Of foliage on each hill? In other words
did a majority of the leaves on each
plant get a thorough coating, and all
OF the leaves receive at least some of
the spray? The grower should answer
this question for himself by observa-
ton when he sprays. In season like
the present complete protection from
late blight can only be expected when
these conditions are fulfilled. On the
other hand, it is often surprising how
much good is sometimes accomplished
by relatively inefficient spraying.
One nozzle to the row is sufficient
only when the plants are small Thor
oughness in spraying should not be
measured in gallons per acre alone.
Fifty gallons per acre means only
about a teaspoonful per plant per ap-
rlication-far too little when the plants
are large, if the work is to be effective.
Was Freshly and Properly Prepared
Bordeaux Mixture Used?
The Station recommends only fresh
lv prepared Bordeaux Mixture and
does not recommend any Just as good"
substitute. The Station has never tried
any commercial or home prepared ma
terial which. when used in economical
amounts. equalled Bordeaux Mixture