CEBEALS 357 



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

 quently shows soft rot of the shoot in very young seedlings. 



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

 the surface of the ground. , 



The causes of these rots have not been fully studied, but 

 they are probably due to fungi or bacteria or both. 



Spotted blight {Macrosporium sp.). — Small black spots 

 of mold upon poorly filled grains sometimes occur, occasion- 

 ally affecting field areas of considerable size. Though this 

 disease has been reported from So'uth Carolina, North 

 Carolina, Georgia, Alabama, Louisiana, and Texas, it is 

 not seriously destructive. 



Speck, pip (Saprophytic fungi and bacteria) . — The grain 

 in some instances bears one or more discolored, often sunken, 

 circular areas, 1-3 mm. in diameter, bounded by dark mar- 

 gins with the centers gray or pale buff in color, and often 

 with a minute dark spot in the very center. In other cases 

 the grain is shriveled and distorted without any definite 

 spot. The interiors of the grains are chalk}^ and brittle, 

 and of such inferior quality as to be largely depreciated 

 in value. Not infrequently 10 to 25 per cent of the 

 grain is affected, and in some cases nearly 100 per cent. 

 Their germinating power is much reduced. 



The disease is caused by the invasion of saprophytic fungi 

 or bacteria into wounds caused by sucking bugs. Methods to 

 control these insects have not been thoroughly worked out. 



Rust (Physiological). — The leaves die gradually, begin- 

 ning with the tips of the lower ones. Red spots and 

 streaks usually appear before the leaves lose their green 

 color. The plants are dwarfed, the roots poorly developed, 

 and the heads small and light. 



