The Mount Holly news. [volume] (Mount Holly, Burlington Co., N.J.) 1891-1942, 1914-07-14
Tomato Mosaic in Burlington
County.

Reports have been sent to the State
Agricultural Experiment Station at New
Brunswick that in various fields of
tomatoes near Mount Holly the plants
are assuming a yellowish appearance,
which is thought by some to be due to
the first stages of leaf spot, the disease
which takes large toll of tomatoes
nearly every year. Investigation in
several fields shows that many plants
that appear yellow are suffering from
the disease known as tomato mosaic.
This gets its name from the peculiar
yellowish nothing of the leaves, and is
similar in many respects to the mosaic
disease of tobacco, which causes SINH
lar nothing.
The effect of the disease on the plant
is always serious, and especially so when
lit appears so early in the season as it
has this year. The plants are much
stunted, and fruit formation is prevented,
or, if fruit is already set, it rarely be-
comes large enough for use. Different
plants are affected in different ways. In
some cases the leaves are of nearly
normal size but irregularly notified with
yellowiSh green. Sometimes the leaves
are much reduced in size and punched
in a dense rosette instead of being loose
and open. Occasionally some of the
leaves assume narrow form resembling
fern leaf. Mosaic can be distinguished
from the leaf blight or spot (Septoria)
by the fact that it usually attacks the
younger leaves first, whereas Septoria
attacks the lower, older leaves, and may
sometimes be found at this time of year
on the yellow leaves at the base of the
plants. The Septoria spot is also much
darker in color, brown or purple rather
than yellow, and more regular in shape,
usually round.
Mosaic has been becoming more seri-
Gus for several years past, and promises
to become one of our most serious dis
eases. The greatest difficulty lies in the
fact that we know neither an actual
cause nor a sure cure. There is evidence
that sterilization of seed beds, either
under glass or in the open, with steam
or formalin, would assist in the control
AS the disease is probably spread through
the plant in the sap, it is likely that in
sects which either eat the leaves as a
whole, like the potato beetle, or suck the
juice, like the plant lice, may tend to
spread the trouble from plant to plant
If this is true, the fewer the insects the
less cases of the disease there will be.
Possibly the red and green plant lice,
which in some fields are unusually nu-
merous this year, are the chief offenders
The control of these lice, however, is no
easy matter, because sprays too often do
not strike the under sides of the leaves,
where the lice feed. Diseased plants that
are at the same time affected with lice
should certainly be destroyed, together
with the insects upon them. So far as
we know, Bordeaux mixture, or other
materials used for the protection of the
plants from leaf spot or insects, will not
directly affect this disease, although if
the insect theory is correct, they may be
of indirect benefit. When there are but
few plants in field affected with mosaic,
they may be removed and new plants
set, if the season is not too far advanced
and if the reset plants are of such size as
to make picking from them reason
ably certain.