CEREALS 369 



often not until the glumes have been opened, and their con- 

 tents examined, that the presence of the smut mass is 

 detected, covered with its membrane, and resembling the 

 wheat grain in size and shape. It may be recognized by 

 an expert observer by its peculiar, disagreeable, penetrating 

 odor, and by the deeper green color of the diseased heads. 

 The smut masses are often so firm as to remain unbroken 

 through threshing, but they may be recognized among the 

 grains by their darker color, greater plumpness, absence 

 of groove and germ, and finally by crushing them and 

 liberating the black spores. 



The disease is particularly destructive in that its presence 

 signifies not only loss of grain due to replacement by smut, 

 but also loss in value to the good wheat, which may be 

 largely depreciated in price by the presence of the bunt. 

 Often bunted wheat is worthless for milling purposes and 

 even for cattle food. Bunt constitutes for these reasons 

 one of the worst smuts in the world. Strong fanning re- 

 moves part of the smutted grains, but troublesome wash- 

 ing processes must be used to remove them all, and even 

 then the results are not entirely satisfactory. 



Many smut spores naturally find lodgment upon the 

 surfaces of healthy grains from smutted fields, or they may 

 be carried from farm to farm upon the threshing machine. 

 Upon planting such seed the following season these spores 

 are ready to attack the seedling grain plant. The fungus, 

 after gaining entrance into the seedling, grows with it 

 throughout the season, and appears again at harvest time 

 as spore masses within the chaff. Affected plants are 

 usually smutted in every head and every grain in the 

 head. 



2b 



