Smyrna times., 1927-06-08
COMBAT BLACK ROT IN GRAPES
Nineyardists About Smyrna Are Now
Spraying Their Vines Systemati-
cally-HOpe For a Big Crop

Spraying Their Vines Systemati-
cally-HOpe For a Big Crop
Notices We're sent out last week
Russell E. Wilson to the two hundred
commercial grape growers in the
county and state with view to again
call their attention to the spray cal
endar which was furnished each of
these vineyardists early in the sea
son, and also to placing particular
emphasis upon the necessity of MAX
ing the pre-blossom application at a
stage in the growth of the fruit clust-
ers when from five to ten percent of
the blossoms are out Aside from
this spray being one of the most i'm
portant applications of the Bordeaux
mixture as a protection against black
rot and other fungous diseases, with
the addition of arsenate of lead, it is
also an effective treatment for the
control of the first brood of the grape
berry moth which has come into this
district during the past few years and
is causing considerable damage to the
crop in some of the vineyards. For
this application, it is recommended
that the growers use the $3.50 form
ula Bordeaux to which should be add
ed IL pounds of powdered arsenate
Of lead, and if the leaf hoppers are
prevalent, it is advisable to add the
nicotine sulphate BLACK Leaf 4O) at
the rate Of one-half pint to each fifty
gallons of spray mixture. According
to the experimental ard demonstra-
tional work which has been conducted
in the state during the past five years
under the direction Of Dr. Thomas F.
Manns, Plant Pathologist of the Del
aware Agricultural Experiment Sta
tion, black rot dissemination was OBJ
served to be the heaviest four seasons
out of five during the blossoming
period, indicating that if the pre-blos-
som spray was omitted this disease
could not be successfully controlled on
the fruit as it develops later in the
season. Although these important
facts We're discovered by Galloway
who conducted experiments in Nir-
ginia in 1890, and also by Selby who
carried on work of similar nature
in Ohio in 1900, they have been over
looked to a great extent, and have not
been given as much consideration as
such information deserves in this pro
gram of grape disease control. The
notwithstanding spray was effective
in controlling black rot in the sum
mer of 1926 in Delaware when drouth
prevailed until after the grapes had
blossomed. This spray should be ap-
piled Immediately following the bios
soming period, and should consist of
the $3.50 formula Bordeaux with the
same additions as recommended for
the predecessor application. In the
event of a severe infestation of rose
bugs, which usually occurs at this
period during the season, it is advis-
ed that one pint of cheap molasseS be
added to each fifty gallons Of spray
solution. This serves as an attrac-
tive bait for the rose bugs, and the
arsenate of lead acts as a poison for
them. The fifth application Of Bor-
deaux for the further protection
against all fungous diseases, and all
insect troubles including the root 7
worm should be made when the young
grapes are the size of peas,and should !
the same ingredients as are
used in the predecessor spray. Tn
der normal seasonal conditions this
fve-spray program is sufficient to in
sure clean fruit at harvest time, but /
if the weather during the latter part
of August should be damp and very
hot, it may be necessary to apply an
other spray just as the fruit beings
to ripen. For this particular applica
tion, however, care must be taken to
use only colorless materials such as
soda, ammoniacal copper carbonate, !
or neutral copper acitate, in order to
avoid the possibility of discoloring the
fruit with the spray residue.