Daily Kennebec journal., 1922-06-20
Brown Patch Turf Disease Controlled
With Bordeaux

The brown patch fungus, which
causes serious blights of potatoes and
tomatoes and great loss to other farm
crops, has been recognized in recent
years as the source of much damage
TO fine lawns and golf greens, former
ly attributed to drought and sun
scald. The problem of controlling
this parasite has been studied by the
United States Department of Agri-
culture, which finds that the fungus
can not be killed out once it has
gained foothold, although it can be
prevented from spreading by persist
ent spraying with Bordeaux mixture
of the proper strength.
The first evidence that the fungus
is present on the lawn is the appear
ance Of small smoky looking spot
that is most easily seen early in the
morning. The grass looks much as if
boiling water had been poured on it.
On close inspection the fungus is
found TO have a threadlike cobwebby
appearance. BY noon, if the weather
is clear, the spots will turn brown.
White clover, bluegrass. and certain
weeds are immune to the attacks of
for distinguishing the disease in its
later stages from the effects of
drought and sun scald, which are not
so discriminating.
Bordeaux mixture. made with )
pounds Of copper sulphate and
pounds Of freshly burned lime to so
gallons Of water, has been found best
as preventive. The copper sulphate
must be dissolved by suspending in 4
bag i'll a barrel about two-thirds full
Of water. The lime is slaked in an
other barrel by first pouring on
little hot water until the lime be-
comes active and then pouring on
water until it is thoroughly slaked
into milky liquid. The solutions do
not deteriorate if kept separate They
must be mixed shortly before using.
and one of the solutions must be
quite dilute if good spraying mix
ture is to be formed. For this reason
il is suggested that the barrel in
which the sulphate is dissolved
should be two-thirds full After the
two solutions have been mixed
enough water is added to make so
gallons If a smaller amount is need
ed proportionate amounts of the So
lutions should be used
Dry Bordeaux mixture is some
times used and is less disaSreeable to
handle than the liquid form. One
man can do the work alone. There is
no special machine designed for
spreading the powder on turf. but it
may be sprinkled on by hand or
spread by means of one Of the dust
guns used for dusting fruit trees
The grass is protected against
brown patch only when the Bordeaux
is on the leaves. and for this reason
lawns that are cut frequently require
much spraying. They must always be
! sprayed soon after a rain TO keep the
fungus from getting a start. No
more than a week should be allowed
to elapse between sprayinga until late
in the season.
What the cumulative effect Of such
frequent spraying will be on the grass
is not yet known During the growing
season last summer only beneficial ef
fects We're noticed, but during the
winter the leaves of the grass turned
to reddish bronze color and the
plants were slower in starting in the
spring. However, the grass recov-
cred and now shows no indication Of
injury. But nothing can be said
about what may happen after a few
Years of such treatment Examina-
ton of the lawns tested by the de-
partment shows that practically all
the earthworms were killed off, which
is considered a benefit to both lawns
and golf greens.
Persons who have lawns made up
Of shot gun mixtures of grass and
clover need not worry about the de-
structive effects of this blight 1t is
only the very fine turfs made up Of
select grasses that suffer much from
its ravages.