Idaho County free press. [volume] (Grangeville, Idaho Territory) 1886-current, 1916-03-30
ANOTHER WHEAT PEST

ANOTHER WHEAT PEST
The season of 1915 markq ID the first
recorded occurrence of what in Eurone
mas iong been regarded as one Of Tho
most destructive of know n cereal
diseases. reference is here made 70 tba
stripe rust (Puceinia glum /.
Fungus closely related to the weli
known stem rust which ha 90 off,
taken big tolls from American wbeo,
plns. stripe rust, in the United States
SO far as careful observation has thns
far shown, is confined to the Poc;f;o
coast and tributary inter-monnta;n
states. 1t has been reported as be;na
very abundant in certain of the who's
producing valleys of Montana and wa /.
particularly marked as an epidemic IN
and Idaho. ''nins'on'
we nave at our disposal no effective
method OF preventing or controlling
outbreaks of grain rust in the sense
that we may prevent or control The
occurrence of oat smut or the stink;n .
smut of wheat, but in the ease of the
stripe rust we may possibly delav its
appearance in the Mississippi Valley
II the farmers avoid planting wheat
known to have been grown west If tbo
looth meridian, line passing tbrouob
eastern Montana. =
1t is a we'll known fact that tboro
ands of carloads of wheat from Monte
ma and the Pacific Northwest were
shipped during the fall and early win,
Ter TO Minneapolis, Duluth, and other
ld-Western points. Some of this
wheat may have been purchased as seed
IN those parts of the Mississippi Valley
where winter wheat is grown, and there
is a slight possibility of the stripe rnst
having been introduced or in future of
Its being introduced, through the plant.
ing of such wheat. On the other hand
1t seems not improbable that the stripe
rust may have been resent in the
United States to an inappfeciable ex-
tent for several years, and that prior
to 1915 it had had opportunity to es-
tablish itself in sections east of it's
present eastern limits, but because of
possible unfavorable conditions NAV
have failed to do so.
The stripe rust does not confine its
ravages to wheat alone, but is known
to occur on barley, rye, emmer. and
certain wild grasses. Unlike the stem
rust, it has no known secondary host
and is, therefore, probably propagated
solely by means of its summer or uredo
spores. This fact in itself diminishes
somewhat the probability of the rapid
spread of this rust over great dis.
tances, for it is true that its uredo
spores can not endure prolonged dry.
ing.
In parts of this country where stripe
rust was most severe, the actual damage
resulting to the crop did not seem seri-
Gus. However, in regions of high
humidity it might prove far more des-
tructive than stem rust, and for this
reason it is matter of great impor-
lance to keep it out of the great wheat
growing states of the Mississippi Val.
ley.
The symptoms of the stripe rust are
peculiarly Characteristic, and the obser-
yer is not likely to experience much
difficulty in distinguishing it from
other cereal rusts. The uredo or sum,
mer spores develop in more or less well.
defined lemon-yellow stripes on the
leaves, leaf sheaths, and glumes. Tn
cases of severe infection the many
stripes on a leaf may be 50 close toge
Their as to appear to unite laterally to
the extinct of involving the entire leaf
The teleutospore or blackspore stage
appears later in the season in the form
of long, black, or dark gray spripes on
the leaf sheaths, culms, and sometimes
the glumes. Specimens seeming to
answer the above description should be
forwarded to the pathologist, Office OF
Cereal Investigations, Washington, d
G. Fl. B. HUMPHREY,
Pathologist, U. s. Departm ent of Ayr