DISEASES OF CULTIVATED PLANTS 
391 
brown (dead) areas in the leaf blades, readily identified by the microscope. All 
, diseases of the young corn attract notice, but it is not certain that there is need 
to apply fungicides for this fungus, though such might prove successful. 
The smut boils 
shown here later burst open and scatter masses of smut spores. 
Fig. 45. Stem of maize attacked by smut. 
or decays where the air circulates in contact with 
silage. We have investigated the mofd fungus 
(Penicillium sp.). This is possibly the same blue 
mold which we have found to attack fruits in 
storage and transit. It is not an active organism 
and must be held in check by control of conditions 
in the silo. 
Corn Smut is a well known disease, attacking 
leaves, shoots, ears, tassels and brace-roots of corn, 
converting the diseased parts into masses of dirty 
(smutty) spores of the fungus (Ustilago Zeae 
(Beckm.) Unger ). A brief article upon corn smut 
will be found in Bulletin 78. (See also Bulletin 92 
of the Kansas Experiment Station). The corn 
smut may be propagated by smutty seed, although 
Corn Rust (Puccinia 
Maydis Berang.) is met 
with in greater or less 
abundance upon corn every 
season, the greater abund- 
ance usually being in rainy 
seasons. The rust causes 
small oblong or elliptical 
spots on the surfaces of 
leaf and sheath and in the 
spots are contained red- 
dish-brown spores of the 
rust. The shade of the 
spores will vary with the 
time and development of 
the fungus. Here, as with 
wheat, the fungus passes 
through the uredo and 
teleuto stages. 
Silage Mold. At times 
we have complaint of mold 
in silos where corn silage 
is stored. Doubtless there 
is some loss in nearly all 
cases from different molds 
Fig. 46, 
destroyed by smut, 
may be found showing different 
forms of attack, 
An ear of corn partly 
Other ears 
much more likely to be carried by the transportation of the yeast spores 
of this smut fungus which may light upon any young growing part and 
produce smut infection. From this fact and from another—probably a greater 
