Atlanta semi-weekly journal. (Atlanta, Ga.) 1898-1920, 1919-05-30

either as DUST or spray. Ine 1unSl-
eide is a mixture which destroys the
disease producing spores on the sur
face of the plant without damaging
the plant tissue itself. The time of
application, the strength of fungi
eide, the manner and frequency of
application all depend upon the time
at which the disease spores were
disseminated, the time at which the
disease begins its attack, weather
conditions and the condition of the
plant. Spray burn" results when
the spray mixture is too strong or
when applied under wrong weather
conditions.
Disease organisms which are dis
seminated by wind and rain, or
which may be brought in on manure,
are those which are carried over on
diseased litter left in the field. The
breaking down of the plants, togeth-
err with deep fall blowing, will de-
stroy much of this litter. The sus-
ceptible crop should be avoided for
two or more years-that is, until the
infectious material has rotted away.
The time required for this will vary
for different diseases, as is noted
under particular crops.
Many of the foliage diseases may
attack and damage the fruit also.
When this happens the control meas
ures advocated for the foliage dis
ease applies to the fruit form also.
There are, however, a number of
diseases which attack the fruit only,
or both fruit and foliage, that are
present in the seed and spread in
comes infected during harvesting or
during seed extracting as, for in
stance, cereal smut melon and cot
ton anthracnose. black rot of sweet
potato, scab of Irish potato, etc.
Careful seed selection will often
70 ha cQn6 from diCpa 20
In many cases, however, the infect.
ed seed appears as desirable as the
healthy. 1t then becomes necessary
to resort to some method of seed
treatment to destroy the disease
organisms present inside or on the
proper seed selection and seed treat
mint will result in clean seed which,
if used on clean fields, will produce
a healthy crop. 49,. Hf0"
Below is list of a few important
diseases which do not, confine their
attacks to one crop: :"
Root knot. This disease is dis
cussed under cotton, but as a matter
of fact, is equally destructive in it's
attack upon many other crops;
namely, truck crops, orchard crops,
and many field crops. In fact, the
only resistant crops are cereals,
grasses, peanut, two varieties OF
cowpea (iron, Brabham) and velvet
beans Since root. knot is a soil
troll will be crop rotation---the intro
ducing of resistant crops into the
rotation until such time as the or
ganism is eliminated or at least great
ly reduced and weakened.
Wilt. This disease may be pro-
duced by a variety of organisms, all
of which live over in the soil: In
I'LL aic-fo Y1f nr.in OF q
have been developed. In other cases
it is necessary to follow out the
same procedure as is recommended
for root knot.
wilt (bacteriaD. This disease
may be carried over in some dis
eased part which can usually be
destroyed. Its spread is due, how
ever, to insects and it is through
the control and eradication of these
insects that relief will come.
Damping off This name is applied
to any disease organism which at
tacks the young Seeding, resulting
in a rotting of the stem near the
ground and destroying the plant. In
the seed bed it is, very common, at
lacking cabbage, caulifiower, pepper,
tomato, collard, lettuce, pine seed
lings, etc. The following control
measures are suggested:
Use a sandy soil in flats or beds.
Arrange for a good circulation of
air. so that the surface soil remains
dry. Space plants fairly wide, so
that the sunlight may reach all par,
of the plants.
If necessary to protect plants
from: the sum- arrange a screen
which isseasyo moved soothatsit may
sbe- taken off duringfi the dark 5Nea tn
er. Avoid, excess water. aAftcr' the
disease has begun it's work, spray
with a dilute solution of bordeaux
or apply warm, dry sand to the Fur-
face soil about the plants. The dis
ease is favored by moist, warm,
close, shady conditions.
Southern blight (Sclerotium rolf
sid. This is soil disease, the or
ganism existing upon humus when
no host plant is present. A very
large number of plants are suScepti-
BILE: tomato, pepper, egg plant, po-
tato, melon. cantaloupe, cotton,
bean, cowpea, beet, carrot, cabbage,
squash, sugar cane, many grasses
and a large number Of ornamental
perennials. A discussion of symp-
toms is found under the head Of
beans, pepper, etc. Soil steriliza-
ton, where practicable, is most
satisfactory means of freeing the
soil from disease organizations. Oc-
casionally, spraying the soil with a
solution of formaldehyde Gone pint to
80 gallans) or with ammoniacal cop
per- carbonate will give the desired
result. Crop rotation, and the use of
resistant crops, will undoubtedly re-
duca the possibility of damage. All
refuse and litter should be Destroy
ed The most logical means of pre-
vention lies in the possibility of de-
veloping resistant varieties.