The Palatka news and advertiser. [volume] (Palatka, Fla.) 1908-19??, 1913-04-18
TOMATO RUST
By 0. F. Burger of Agricultural EX
pertinent Station, Gainesville,
Florida.


The tomato crops of Florida have
been attacked from time to time by
disease which is called in different
localities and by different growers, to-
mato rust, tomato blight, tomato leaf
blight, or tomato black spot. This
disease should not be confused with
fungus blight, or with the bacterial
blight of tomatoes, neither of which
can be successfully controlled by Bol-
deauX mixture. Rust causes more or
less damage to the crops, mainly &C
cording to the local climatic condi-
tons In some years the only evil
dence of the disease may be a few
dried leaves on the tomato plants,
while in other years all the leaves are
destroyed and the tomato fruits are
much spotted.
Symptoms of the Disease.
Sometimes the tips of the leaves
become brown and dried, the rest of
the leaf blades remaining green, or
becoming more or less spotted with
brown. At other times small brown
spots appear at once on many of the
leaves, and spread rapidly so as to
destroy the whole of these leaves.
The stems and fruits usually remain
green after all the leaves have been
destroyed. In advanced stages of the
disease the tomato stems and fruits
are affected, as we'll as the leaves.
The stems become spotted with brown
spots, which frequently grow togeth-
er, forming a brown crust. Brown
circular spots appear on the fruits.
These spots often make their appear
ance after the fruit has been picked
and packed. When such tomatoes
arrive at the market they are sold as
inferior fruit, or thrown away.
Preventive Measures
The disease can be successfully con-
5lolled by spraying the tomato plants
with Bordeaux mixture. Bordeaux
mixture is made of quicklime and
blue-stone "copper" sulphate). Three
pounds of copper sulphate and three
pounds of quicklime in fifty gallons
Of water have been found sufficiently
strong to prevent rust. If properly
made, it may be used as strong as
six pounds of copper sulphate and |
six pounds of quicklime to fifty gal
Ions of water, without scalding the
plants.
Bordeaux mixture is not a cure, but
a preventive. 1t will not cure an in
fected leaf, but if it is applied to
healthy leaf in such manner that the
whole surface is covered with a film
Of the mixture it is impossible for it
o become infected.
1t is best to commence spraying
while the plants are in the seed bed.
They should receive two or three good
spraying before being taken to the
field. The disease does not prove de-
5tructive with sufficient regularity to
spraying every year; but We
should always be ready for it, When
he plants in the field show symptoms
If the disease we should be prepared
o spray them thoroughly at once.
Two or three sprayings at least are
required to get the disease under
'Ontrol. The disease depends great
leal on weather conditions. The
grower cannot foretel the weather
so preparations should be
made to ensure against loss from
his disease.
Cause of the Disease.
Tomato rust is caused by a fungus
allied Alternaria solani. This fungus
s propagated by small brown club
haped bodies, known as spores. The
pores are so small that they can be
cen only by the aid of microscope.
hey are carried by the wind from one
liant to another The spores lodges
n the upper side of the leaf, and.
there is CROUCH moisture, it will
terminate. A small tube grows out l
rom the spore, penetrates the skin I
f the leaf, and kills and feeds on the i
EFF tissue, causing q dad brown T
pot. :