Americus times-recorder. [volume] (Americus, Ga.) 1891-current, 1915-02-22
INVESTIGATION
STOPS ROOT KNOT
State Board OF Entomology Tells Of
Disease That Attacks Many
Plants.

Atlanta, Especial Georgia
ectt1n planters, especially where the
SCH is sandy. have had considerable
1roable with the disease known as
root knot, caused by minute eel worms
or nematodes, which bore into the
roots and live there. The irritation Of
xheir presence results in the formation
Of irregular sweHings or gals, varying
in size from tiny engagements on
the smaller roots to knots an inch or
more in diameter on the large ones.
Unlike wilt, or black root, root knot
attacks very large number of plants,
many of which are important farm
crops, says State Entomologist E. Lee
W9rSham- The crops most severely at
tackled by root knot include soy beans,
beets, czntaloupe, carrots, celery, bur
clover, crimson clover, COW pea (all
varieties except Iron and Brabham
and other Iron hybrids), cucumber,
eggplant, figs, lettuce, okra. peaches,
peeans, pomegranate, potato, satisfy,
squash, tobacco, tomato, watermelon.
Plants less severely injured by root
Knot include the following: Alfalfa,
asparagus, lima bean, snap bean, cab
bage, sweet clover, collard, cotton,
mulberry, onion, garden pea, sweet po-
Eato, radish, spinach, strawberry, su-
gar cane, common vetch, hairy vetch.
The male worms are too small to
5 BE seen by the naked eye, but the
female when full of eggs assumes a
spherical shape and may be often dis
1inguished in freshly broken roots as
glistening bodies half the size of
pin head. Each female lays several
hundred eggs Root knot is essentially
a disease of light or sandy soils. It
may be transferred from one field to
another by any agency which will car
ny the nematode or their eggs. II
may be spread by drainage water or
introduced by nursery stock.
Controlled BY Rotation
1t has been repeatedly demonstrated
ny many farmers that root knot can
be controlled by the use of proper
crop rotations. The principles on
which such rotations are based are
Sfhe use of crops immune to nematode
attacks until the nematodes are suf-
6ciently reduced so that crops sus-
eeptible to them may be profitably
grown; and in the second place, the
removal of all weeds subject to root
knot The use of crops that will re-
turn profit and the building up of the
fertility of the soil are also import
ant considerations. If the land is
very badly infested with nematodes
as well as wilt, a two or three year
rotation with immune crops is rec
commended before susceptible crops in
Guiding cotton are grown. In one or
two years thereafter the rotation with
immune crops should be repeated I'm
mune crops, alternated with suscepti-
Bile ones, will reduce the nematode in
jury to a minimum.
The following crops are largely or
entirely immune to root knot: Barley,
velvet bean, beggar weed, chufas,
cUrn, Brabham COW pea, Iron COW pea,
Iron hybrid COW pea, bermuda grass,
crab grass, grasses (nearly alb, KAT
Or, millets tnearly ALL, milo, winter
oats, peanut, rye. sorghum, wheat
The farmer generally will have to
work out his own problem as to rota-
lions, depending on location, but the
State Board of Entomology will be
glad at al. times to furnish any DOS
Sible assistance or information.