SEEDLING BLIGHT AND STACK-BURN OF RICE. 5 
eolor. Dark bands of sclerotial tissue may be seen on kernels in- 
fected with the sclerotial fungus. 
The climatic conditions in the rice-growing sections of the South 
favor the development of these troubles. The humid atmosphere 
and high temperatures are conducive to a vigorous growth of the 
various fungi concerned, and the humidity is unfavorable for the 
drying and curing of rice, thus leaving it exposed to attacks by these 
organisms. ‘The drier atmosphere and the rather low night tempera- 
tures which generally prevail in the rice-growing sections of Cali- 
fornia during the crop season probably are not favorable to the 
development of most of these fungi. . 
There is one type of flecking known as “‘blast’’ in California. In 
1919 seed of this type collected at various points in the State was 
found to contain an Alternaria in the diseased spots. Brown spots 
or totally brown glumes characterize this'trouble. The kernels are 
also yellowish to brown in color beneath the diseased glumes. Some 
of the spots have lighter colored centers. The fungus might have 
been growing as a 
saprophyte in these 
dead areas, but the 
failure to find it associ- 
ated as constantly with 
_ healthy kernels seems 
to indicate that to 
some extent it was 
responsible for the in- 
Fic. 2.—Camera-lucida sketch of the germ tube from an Alternaria jury. When these 
spore penetrating the epidermis of the leaf of a rice seedling. kernels were dehull ed 
‘ y] 

surface sterilized, and placed in damp sterile chambers the spots 
increased in size, and a growth of Alternaria appeared on the surface. 
Alternaria also was isolated from rice seed grown in Louisiana. 
In Louisiana a leaf spotting of seedlings was noticed as being 
quite common before the irrigation water was applied. The spots 
were small, indefinite in outline, and light brown in color. An Alter- 
naria was found constantly associated with those spots. By examin- 
ing carefully under the microscope these young leaves, cleared by 
soaking in equal parts of 95 per cent alcohol and glacial acetic acid, an 
‘Alternaria spore could be seen in the center of almost every spot, and 
often the germ tube could be seen extending from the spore and 
passing through the epidermis into the leaf tissues (Fig. 2). An 
Alternaria leaf-spot of black Italian rice and of C. I. No. 1564 was 
found at Bellflower station, near Los Angeles, Calif., but it was not 
determined whether or not this was identical with the form producing 
the “blast’’ of rice kernels in the Sacramento Valley or with the 
3866°—22——2 
