The Aberdeen weekly. [volume] (Aberdeen, Miss.) 1878-1933, 1920-03-05
Smut Morka Overtime IN Trying
to Snuff Out Young Seedlings
BY Forming BHsters.
fUAGUs CAUSE OF kiiKEaI
Centre! Of T-oub's - Accomplished BE-
Chnroing Locs.isn Of 0-d to
Clean Soii-Aise Plant Sets
Instead Of Seed.

netic attraction which apparently
draws disease ef vnrious kinds and
conditions 10 the onion crop Take.
for instance, onion smut. II works
overtime in trying TO snuff out the
young seedlings by forming brownish
black. elongated blisters which finally
split the leaves and expose the pow
derry black mass OF spores within the
interior Of the blister A specific
fungus causes this onion ailment the
spores wintering In the ground and
again attacking the young seedlings In
the spring.
The onion is susceptible TO the fun-
gus only while In the young Seeding
stage. After the plants reach a height
or three TO four inches they become
immune to further infection. Smut
spreads slowly in the soil, but an
infested area in field will gradually
become larger and more severely dis
eased each year onions are grown on
such an area. The spores are spread
on farm implements. the feet OF men
and animals, by surface water. and in
dust carried by the air. Purchasers
OF onion sets should use caution that
they do not contaminnte the soil by
planting smutted sets.
Control is accomplished in home gar
dens by changing the location of the
onion bedStO clean soil. or by planting
sets instead of seed. In large com
mercial onion districts of the northern
states formaldehyde solution is ap-
piled In the furrow with the seed, as
this diSinfectant holds the fungus in
check. One fluid ounce of 81 TO 40
per cent formaIdehyde solution is used
with each gallon of water. this diluted
solution being applied at the rate of
200 gallons per acre or | gallon to 49,
feet of row. Farmers bulletin No
1O6O. recently issued by the United
States department of agriculture. de-
scribes in detail the apparatus used in
applying this MISUNDERSTANDING seed
protector. AS rule, ii costs about
81 an acre to insure. the onion crop
against smut losses in this manner. IT
Is advised that the tops of diseased
onions be burned after harvest in or
der TO prevent the return of infected
onion refuse 10 the soil The spread
ing of waste from onion warehouses as
a bad practice.
A Destructive Plant Disease
Onion mildew or blight is some
times serious in the cooler and more
humid onion districts. The disease
commonly starts IN the field in spots
and spreads to the surrounding areas,
its development being greatly aided by
moist weather. 1t centraliZes its at
tack on the leaves. which turn yellow,
become covered with furry growth.
and eventually collapse. The disease
occurs wherever onions are grown eS-
tensiyely. although the control varies
in different sections. A fungus causes
the disease, the furry masses on the
affected leaves being branches of the
fungus, which bear abundant spores.
Warm weather promotes spore ger
and hence is favorable to
the spread of the disease.
AS the spores winter in the onion
field, an efficient crop rotation is one
commendable method of control. the
supplementary growing of cabhages.
potatoes. and sugar beets with onions
being valuable. Good soil drainage
also helps 10 reduce the blight since
it decreases the moisture in the air
near the surface OF the soil. Good
air drainage of the fields is also es-
sential so that excessive dew and fog
may be avoided. Rosin fish-oil soap
as a sticker makes the use of Dor
deaux mixture effective I'm controlling
onion miIdew. The bordeaux mix
ture consists of four pounds of cop
per suIphate. four pounds of quick
lime, three pounds of .rosin fiSh-oil
soap. mixed with water to make so
gallon solution. Complete directions
for making this spray are furnished
I'm the department of agriculture bull
letin.
Onion leaf mold is a disease of
minor importance except in Louisiana
and California, where 1t occasionally
causes large losses. 1t occurs in
mid-season and causes the tips of the
leaves TO die back. No satisfactory
control has been perfected.
Strict attention TO sanitary meas
ures and careful sorting of diseased
bulbs at harvest time are the chief
means of controlling Fusarium rot.
which reduces the roots TO a mass
of white moldy growth.
Root-knot of onion is an eeIworm dis
ease which dwarfs the aboveground
parts of the plants and reduces the
size of the bulbs. The eelwOrm, n
minute nematode. lives I'm the soil and
causes gals on the onion roots. Live
steam applied under considerable pres
suer will free the infested soil of eel
worms. In large areas where steam
ing is not practicable. nematodes can
be reduced by a proper system OF
crop rotation. as the avoidance of sns-
ceptibIe crops staryes out the eel
worms. However. to- avoid root-knot
II is never advisable to plant onions
on land known to be eelworm In
tested.
Onion smudge. confined largely to
the white varieties. results in
smudgy, unsightly appearance of the
bulbs and an ultimate reduction in
the market quality of the crop. As
fhe disease is dependent largely on
abundant moisture. special care isnec-
essary in handling the white varieties.