The Indianapolis journal. [volume] (Indianapolis [Ind.]) 1867-1904, 1884-07-05
Rust In wheat.
philadelphia Record.

Philadelphia Record.
Rust is parasitic plant, with neither leaves
nor roots, but it steals its food from plants which
have leaves and roots Professor G. E. Bessey.
of the Iowa Agricultural College. has given rust
considerable attention, and we are indebted to
his labors, the result Of which he gave IN the.
New York Tribune, for a fuller acquaintance
with the habits of the plant and the manner in
which it is propagated. The first stage Of rust
is passed on the barberry leaf, where it may be
found in the spring forming yellow patches
Under an ordinary lens these patches are seen
to be made up of many beautiful little cups
called cluster cups and each cup is filed with
orangecolored spores. The latter soon fall out
and are blown away by the winds, some finally
alighting on the leaves of wheat. Here
they germinate and soon penetrate the
process of rapid growth in the soft interior
tissues In few days, if the conditions have
been favorable, masses of reddish spores are
formed by the parasite just beneath the surface
of the leaf, which finally break through the.
skin forming the red rust patches 50 common
on grain. Every red-rust spore may produce
more red rust by falling on a leaf and ger
minating there. In this manner a small amount
of rust in o field may, under favorable condi-.
lions thigh temperature with an abundance of
moisture) give rise to enough to destroy the
whole crop.
+ The red-rust spores appear to be incapable
| of living through the winter, SO there are
produced a little later from the same para
site, larger black patches Of thick walled spores
This is the blaek=rust stage, and is the last
to appear. 1t often natures after the stalk is
dead, and so appears at first sight to be much
less harmful than the preceding red rust, but
these black spores are so tough that they endure
the winter and terminate in large numbers the
next spring, They first grow a little thread-like
stalk, and on this are produced several exceed
ingly small spores, known as sporidia These
last, on account of their minuteness are widely
dispersed by the winds, and some falling upon
barberry leaves, terminate there and thus start
the cluster cups The complete round of life
is as follows: l. The cluster cup on the bar
berry q The red rust on the wheat. B. The
black rust on the wheat A. The termination of
the black rust spores, forming sporidia which,
in turn, produce the cluster cups again It
cannot affect old leaves, are able to germinate
upon and enter into the very young leaves of the
wheat and when they do this they are capable
of producing. the red-rust stage, the cluster
cup being omitted.
IL wheat grams are terminating at the same
time that the. sporidia are being produced, the
young wheat plants are liable to be inoellated
with the parasite. Winter wheat terminates in
the fall, while the Sporidia are produced in the
spring, and there is no danger to winter wheat.
But w. spring wheat, which terminates at the
exact time the sporidia are forming, the danger
is great The reason why rust is common iV
places where the barberfy is not grown is simply
because the cluster cup stageis omitted as the
sporidia are able to directly inoculate the young
spring wheat plant. In order to avoid the evil
it should be made special object to destroy all
the straw which has black rust upon 1t, as the
black spores have been known to produce nlyri-
ads of sporidia upon straw which had been used
for the winter protection of strawberries. Con-
sequently, 1t is also dangerous TO have straw
scattered around. Every precaution should be
taken in communities to avoid the dissemination
of rust as its spread can be partially prevented
by organized effort