22 
Colorado Experiment Station 
CEREALS. 
Rusts. —The cereal rusts are too well known to need descrip¬ 
tion. They occur on both stems and leaves, and in many instances 
cause serious injury to the crop. 
Control .—There are no satisfactory, practical methods of con¬ 
trol. Some varieties are more rust-resistant than others. It ap¬ 
pears that plants growing on soil that is well-drained are more re¬ 
sistant to rust than plants on poorly-drained soil. 
BARLEY. 
Covered Smut. —Smut masses enclosed by thin covering, 
which breaks open soon after heads appear. Smutted grains 
(“smut-balls'A often occur in threshed grain. Chaff as well as 
grain is smutted. Spores are blown from infected heads to healthy 
grain. These spores remain over winter on the outside of the 
healthy grain. 
Control.— the formalin sprinkle as given under bunt of 
wheat. 
Loose Smut. —Smut masses not enclosed for any length of 
time by thin covering. As soon as smutted heads appear, the spores 
are scattered by the wind, and nothing but the bare stalk of the 
head remains. “Smut-balls” not formed. Smut mass olive-green 
in color. Appears earlier in season than covered smut. It is the 
more common sort of barley smut with us. Infection of sound seed 
always takes place before harvest time. The smut is carried over 
within the seed, not on the outside, as in the case of covered smut of 
barley. 
Control .—Use hot water method as described under loose 
smut of wheat. Note: In the case of barley, the water in Tub No. 
2 is kept exactly at 125 degrees F., and the grain is left in it 15 
minutes. 
WHEAT. 
Stinking Smut, or Bunt.— Bunt is the most destructive 
smut of wheat. It is more common than loose smut of wheat. 
Bunt is exclusively a kernel smut. The contents of the 
grain of wheat are entirely replaced by a powdery mass of black 
spores. The spore mass or “smut-ball” is rather hard. Bunt usu¬ 
ally is not noticed until the heads are mature. As a rule, all grains 
of a head, and all heads of an infected plant are smutted. Smutted 
grains, as compared with healthy ones, are darker in color, lighter 
in weight, plumper, and more easily crushed. When the smutted 
grain is crushed, numerous black spores are liberated, and the 
grain gives otf a characteristic decayed fish odor. The spores get 
on healthy grain usually at threshing time: the smut-balls are 
