The pioneer express. [volume] (Pembina, Dakota [N.D.]) 1883-1928, 1909-02-19
DRY ROT OF corn
Disease Witch Is Causing Concern.

Disease Witch Is Causing Concern.
according to T. j. Burrill and ].
L. Barrett of the Illinois station the
groups of diseases of corn known un.
Ger the general name of dry rot has
become of sufficient economic impor.
lance during the past four or five
years to cause general concern among
farmers in corn-growing regions.
In 1906. the year in which there
was the greatest amount of dry rot, so
Tar as any records have been made.
the loss was As per cent. of the entire
crop in Illinois. This represents a
loss Of over 100000 bushels, having
value of more than $5,00O,O00. The
loss in 1907 was less than two per
cent. of the crop, or about $4,000, COO"
The name dry rot is derived from
the way the ears are affected in the
field. "1n general the husks tend to
turn prematurely yellow to sooty, and
the ear becomes partially or wholly
shriveled and much decreased in
weight. Sometimes the ears remain
upright with the husks closely adher.
ing to them. In other cases the
shanks are weakened and the affected
ears hang limp from their attachment,
or the diseased condition may not be
detected until the husk is removed"
There are several kinds Of dry rot,
due to different causes. The most
onG fhof }n6
to Burrill and Barrett, has during the
past two seasons caused about 80
per cent. of the damage in Illinois.
is due to fungus known as Diplo.
dia maydis. Ears infected with this
fungus "shrivel up more or less, dark
en- in color, and become light in
weight.
''The kernels are also shriveled.
very brittle, and loosely attached to
the cob. The fungus penetrates all
portions of the ear, kernels, cob, and
husks, and produces many dark-brown,
two-celled spores which serve to prop
agate the fungus.
There are several other forms Of
dry rot which are less important, but
cause considerable damage, which
seems to be on the increase. These
are also due to fungi which belong, for
the most part, to the genus Fusarium
members of which cause serious
damage to quite number of our i'm.
portant cultivated plants. -.
in the case of the Diplodia disease
and quite probably in that of the other
forms, the fungus perpetuates itself
over winter on the old diseased ears
and old stalks. 1t is not usually diff.
ficult to find throughout the summer
in old corn fields. where the disease
has previously prevailed, many pieces
of old cornstalks which are infected
with the Diplodia fungus. Stalks
known to be two years old have been
found still producing spores.
"The fungus does not, according to
present knowledge, grow upon any
other host, and upon developing corn
only on the ears. Not so much is
known of the other fungi here con.
cerned, but since 80 per cent. of the
rot is due to Diplodia, less attention
need be given to them. Diseased ears
are fruitful sources of subsequent in.
lection and should be removed as
promptly as possible. This can be
readily done, at the time of husking.
if not before. Keep them in a sep.
arate receptacle and burn them as
soon as practicable. D. In addition to
this, in fields where any considerable
amount of disease has been found.
the stalks should also have attention,
whatever crop is to follow. Some.
thing may be gained by carefully plow.
ing them under and leaving them we'll
covered, but burning may be required
even if this is otherwise bad pro-
cedure. Such field should not be re.
planted to corn for at least two years.
IF the first suggestion is always
followed and the others are put into
practice whenever necessity demands
it, these serious losses may be prac.
tically prevented"