Cereals 



303 



out in South Carolina within the first few years after its 

 advent. No reports whatever of its presence there have 

 been made since 1903. It has since entered the United States 

 through Louisiana. 



The smut closely resembles the stinking smut of wheat. 

 The affected ovaries or grains are transformed into smut 

 masses which remain within the glumes, and so resemljle the 

 normal grains as often to be mistaken for them. The fungous 

 mycelium grows within the stem tissue of the diseased plant 

 and, as is the case with wheat bunt, infection probably 

 occurs in the seedling stage, the fungus remaining unnoticed 



Fig. 161. — Three rice spikelets: A, normal; 

 B, smutted; C, glumes partly torn away ex- 

 posing the spore mass. After Anderson. 



until its presence in place of the grain is disclosed as a black 

 spore mass. 



The disease can be controlled by the method which 

 stamped it out in South Carolina; that is, by the formalin 

 treatment. 



Damping-off. — Two forms of damping-off of seedlings 

 are known : 



1. Rice, not covered, but simply flooded with water, 

 frequently shows soft rot of the shoot in very young 

 seedlings. 



2. Covered rice often shows damping-off spots just above 

 the surface of the ground. 



