Worcester Democrat and the ledger-enterprise. (Pocomoke City, Md.) 1921-1953, 1940-03-22

LracClng considerable aCCenClon. InlS
is due mainly to some very destruc-
tive diseases; such as, red STEELE root
rot, spring dwarf, summer dwarf, and
yellows. The spread of all of these
should be stopped by using strawber-
ry plants that are entirely free from
them.
Red STEELE Root Rot
The red stele root rot disease is
caused by a fungus parasite, which
attacks the roots of the plant. The
small fibrous roots seem to be attack
ed first: later, the larger roots be-
come involved, and all of the affected
roots decay. The disease gets its
name from characteristic red color
that is produced in the central strand
of the affected root. If the bark of
a diseased root is pulled off or cut
away, the central strand will be red.
This central strand is known botanical
ly as the stele. For that reason, this
disease has been called the "red stele
root rot" The disease may be car
ried in the roots of the mother plant
and distributed from them to the
daughter plants; however, the dis
tribution of the diseases from plant
to plant depends on water in the soil,
since the parasite produces swimming
reproductive bodies. This swimming
habit of the parasite accounts for the
fact that the disease is more prevail
ent in the low, wet spots of a field
in which it is distributed than in the
higher, well-drained spots. In light,
sandy soil there is usually very little
red STEELE, even though an occasional
mother plant was infected when set.
In severely infected fields the diseas-
ed areas can be detected by the stunt
ed and discolored condition of the fol-
iage about the time the plants begin
to bloom. Usually diseased plants
produce no fruits of value. In the
worst cases all the roots decay, and
the plants die.
The fungus which causes the red
stele root rot requires cool weather in
which to grow and multiply. 1t can
not be detected in the plants during
the summer. The first case found in
the fall of 1888 was on November IL.
It seems to spread through the. win
ter, and by April it is at about its
worst stage. Ordinarily, nursery
plants should not be dug before about
the first of March, as the diseases
can be detected fairly we'll at that
time. After the organism becomes
established in the soil, it will remain
there for a number of years. In
Scotland, where the disease has been
known for about 20 years, the organ
ism has been known to remain alive
in the soil for years, even when no
Strawberries were grown in the land
during that time. Everyone growing
Strawberries should be very careful
to avoid the setting of plants that
have the red stele root rot diseases.
Cutting across the roots will show
presence of disease. Plant certified
plants that have been inspected for
this disease.
This disease seems to be distributed
rather generally through the north
eastern states and has been reported
from Michigan, Illinois, and Califor-
MIA farther west.
Spring Dwarf
Spring dwarf is the new name for
the Cape Code nematode diseases,
known also as the Northern nema-
tode diseases. This diseases is prev
alent in the Cap Cod seton of Massa-
chusetts and may be rather widely
distributed in the cooler states. At
any rate, it is a cool weather disease,
which can be detected in the, spring
Immediately after the plants begin to
grow. The affected plants become
stunted and the newer leaves take on
a slight glistening discoloration. In
bad cases, the first leaves in the
spring are very small and abnormal
in shape. The disease is caused by
thousands of very small eel-shaped
worms in the bud of the plant. These
worms usually kill the flower bud so
that affected plants bear no fruit. If
the bud of a diseased plant is picked
to pieces in a few drops Of water and
magnified, the worms called nema-
todes, can be seen swimming in large
numbers. These nematodes escape
from the diseased plants during rainy
spells and become distributed to other
plants. They seem to be carried al
so in the runner buds, so that nearly
all the daughter plants produced by
any affected mother plant will have
the disease. The mother plant and
the daughter plants produced by it
are known as the clone. The spring
dwarf then is known as a clone dis
ease. In other words, it affects a