54 
CoLOKADo Experiment StatIon 
as the stem rust. In severe eases of infection, however, a consider- 
able reduction in yield may result. 
Small round orange-red blisters are formed in which are thou- 
sands of red spores. These spread the rust from plant to plant and 
may live from year to year starting the rust anew each spring. Black 
spores are also formed by leaf rust but no plant is known in this 
country that they infect. No effective control measures for this rust 
are known. 
Leaf Rust of Barley (Puccinia simplex) — This rust is very similar 
to the leaf rust of wheat. No effective control measures are known. 
Leaf Rust of Rye (Puccinia dispersa) — There is also no essential 
difference between this rust and the one described above. 
Crown Rust of Oats (Puccinia coronata) — This is a rust somewhat 
intermediate between the leaf and stem rusts. It is found chiefly on 
the leaves but may also occur abundantly on the stems. It lives one 
stage of its life on the buckthorn in the same way that the stem rust 
lives on the barberry. In oat growing sections where the buckthorn 
is plentiful its destruction would undoubtedly reduce the amount of 
this rust. 
Yellow Stripe Rust of Wheat, Barley and Rye (Puccinia gluma- 
rum) — Yellow stripe rust is found on the above three cereals and a 
number of wild grasses. It never occurs on oats. It seems to be 
confined to the westeiai part of the United States although it has 
been found in a feAV places in Colorado. It often becomes destructive 
west of the Rocky Mountains. 
Yellow stripe rust as its name indicates is characterized by the 
bright yellow stripes formed on the leaves of the affected plants. 
The yellow stripes and blisters are also quite commonly formed on 
the inside of the glumes and often on the kernel itself. No success- 
ful control measures have yet been worked out. 
OTHER CEREAL DISEASES 
Barley Stripe (Helminthosporium graminium) (57)— Stripe is a 
serious disease of barley in Colorado. Eields wei-e obseiwed in 1919 
in which as high as 25 per cent of the plants were heavily affect ed. 
Diseased plants show long yellowish to bi*own stilpes on the 
leaves and stems. The heads are also often affected tui*ning a gray- 
ish brown and forming shrivelled grain. In several cases the entire 
])lant may die, usually about the heading time. The spores of Ihc 
