CEREALS 323 



the seed in hot water. Untreated seed gave 36 per cent of 

 smut. One fourth per cent of bluestone gave one half per 

 cent smut. Warm water, 133° F. for five minutes, gave no 

 smut. Kellerman and Swingle soon afterward introduced 

 this last treatment into this country. 



In 1888 the germicidal action of formalin was discovered 

 and this substance was used as a preventive for oat smut by 

 Bolley of North Dakota during the three years preceding 

 1897. 



The Sar treatment was first announced by S\\angle in 

 1898.^ 



The use of the various smut remedies is usually attended 

 by an increase in vigor of the plants, and by an increase 

 in yield in excess of that due simply to the elimination 

 of the smutted grains. The reason for this has not been 

 fully explained, but it may be due to elimination of the 

 fungus from plants which otherwise would have to resist 

 it throughout a portion of their growth period in order to 

 overcome it and to eventually bear grains. An excellent 

 account of the early history of smuts in general may be 

 found in the Report of the Kansas Agricultural Experi- 

 ment Station for 1889, and a comprehensive article upon 

 corn smut in the Twelfth Report of the Indiana Agricul- 

 tural Experiment Station. 



Cereal Rusts in General 



The rusts constitute a complex, intricate, difficult, but 

 interesting group of diseases. It is said that the " average 

 annual loss from rust throughout the United States far 



1 Swingle, W. T., U.S. Dept. Agr. Farmers' Bui. 75, p. 15. 



