Fungous Diseases oe Coeorado Crop Plants 
25 
CORN. 
Smut. —The appearance of corn smut is well-known. Black 
smut masses usually appear on the ears, but also frequently on tas¬ 
sels, leaves, and stems. Black spores are produced in tremendous 
numbers and scattered broadcast by the wind. Spoires may live 
in the soil or in the manure pile. The spores that rest over the 
winter, in the spring produce spores of another type, and it is these 
new spring or early summer spores that infect the corn plant. Any 
part of the corn plant may be infected. Hence seed treatment is 
useless. 
Control .— (i) The formalin sprinkle and hot water treatments 
are useless. Corn smut cannot be controlled by any form of seed 
treatment. 
(2) Corn smut spores may pass through the digestive tract of 
animals without destroying their germinating power. Furthermore, 
the spores may actually grow and reproduce in fresh manure. Use 
well rotted manure, as it contains few or no living spores. 
(3) Remove and burn all smut masses from field before they 
discharge the spores. 
(4) Since spores may remain alive in the soil several years, 
crop rotation is of value. Any other crop than corn may be used 
in the rotation, for corn smut spores cannot cause smut, or be car¬ 
ried over, in any other plant. 
SORGHUMS. 
Smuts. —Under the name sorghum are included milo, kafir, 
feterita, durra, kaoliang, broom com, vSudan grass, and shallu. 
There are two smuts of the sorghum, kernel smut and head smut. 
In kernel smut of sorghum, each kernel becomes a smut mass, and 
the head retains its usual shape. The disease appears early in the 
season. The formalin sprinkle is an entirely efficient treatment for 
sorghum kernel smut. It is the more common sorghum smut. 
In head smut of sorghum, the entire head becomes a large 
deformed smut mass. It is a loose smut. The life history of this 
smut is not well understood. -Seed treatment is probably of no 
use. Cut out and burn infected plants. Rotation of crops may be 
of advantage. Milo is not attacked. 
SUMMARY OF TREATMENTS OF CEREAL SMUTS. 
I. Use the formalin sprinkle for: 
(a) Bunt or stinking smut of wheat. 
•(b) Covered smut of barley. 
(c) All smuts of oats. 
(d) Kernel smut of sorghums. 
(e) Smuts of millets. 
