The Richmond Virginian. (Richmond, Va.) 1910-1920, 1917-10-02
ROTATION CHECKS
TOBACCO WILT
Department of Agriculture I'm the
Esue- Cured Tobacco District.

Washington, D. c., Oct. Crop
rotation is the only method which
will give satisfactory results in con-
trolling tobacco wilt. 1t appears from
tests conducted over a series OF years
in the fue-cured tobacco district by
the United States department of agri-
culture. BY cropping badly infested
land for FIVE years with crops not af-
fected by the witt, the extent of in
jury to tobacco from the disease was
reduced from so per cent to less than
10 per cent.
In arranging rotations, the depart
ment specialists point out, care must
he taken not to grow other plants
attacked by the wilt organisms. The
plants susceptible to attack which
should be avoided in the rotations In
clude tomato. Irish potato. and pea
nuts. Ragweed. which Is very com =
mon In the fiuc-cured district. also
is attacked by the wilt and il IL i'm =
portant, therefore. that this weed be
kept down and. If possible, eradi-
Gated. The crops shown by the tests
to give satisfactory results in rota-
tions are corn, cotton, wheat, rye fas
a cover CROP, sweet potatoes, cow
peas, grasses. red clover. and GRIM
son clover. Oats were not included
IN the tests but It does not seem
likely that this crop is affected by the
wilt.
Five-Year Rotation Recommended.
The tests made by the department
Of agriculture indicate that on badly
infested land the growing of crops
not attacked by wilt for four or five
gears Will give better results than only
three years Of such cropping. The
three-year period however. greatly
reduced the amount of wilt. The
specialists believe that or badly in
tested soil q good general rule IN
not TO grow tobacco oftener than once
in every five years. After the disea SIC
has been brought under control. how
ever. tobacco probably may be grown
safely every fourth vehr. Under no
circumstances should two crops Of
tobacco be grown in succession on In
tested soil.
To keep the wilt off farms not al
ready infested. # is recommended that
seed beds he thoroughly burned 10
insure complete sterilization and that
care be taken not to allow surface
drainage from infested farms 10 reach
the seed bed or the tobacco land.
Great caution should be used IN go
curing plants or farming implements
from farms on which the wilt is
present Tobacco stalks or stems
from INFESTED FARMS SnpuIH not DC
used SIS a fertilizer on healthy soils
Every effort should he made to pre-
vent infested soil or diseased plant
material in any form from reaching
the farm.
Symptoms of Tobacco wilt,
Tobacco wilt produces definite
symptoms in the leaves. the stalks, and
the roots of the tobacco p1ant When
plants are attacked the leaves dror
in an umbrella like manner and the
stalk shows yeliowish to black streaks
when the bark is stripped. Wher
diseased stalks are cut across with 6
knife. Shiny ooze appears. The dis
ca Sc also brings about decided decay
of the root system. TIE organism
responsible for the disease enters the
| plant through the root and eventuall3
brings about a plugging of the yes
sells, thus cutting off the water sup
| ply from the leaves and causing then
/ to perish.
| In the experiments carried on bs