Cereals 271 



still in the experimental stage and is apparently attended with 

 danger to the seed. 



On a large scale, oats may be treated by the formalin 

 method at the rate of 500 bushels an hour, by throwing the 

 formalin solution, by means of a steam pump, against the 

 grain as it falls through elevators arranged with deflectors so 

 as to give proper contact.^" 



The formalin treatments as above given are effective 

 against those smuts in which the spores lie upon the surface 

 of the seeds and in which the smut fungus is not within the 

 seed itself, e. g., oat smuts, wheat bunt, covered smut of 

 barley and rye, rice smut, sorghum, and millet kernel-smut. 



Long time formalin treatment. — Seeds are immersed for 

 two hours in the formalin solution, 1 pint to 40 gallons of 

 water. Favorable results are reported even in those cases of 

 floral infection where the hot-water treatment was formerly 

 thought necessary, e. g., in the cases of wheat loose smut and 

 the covered smut of barley, but complete reliability of this 

 treatment for these diseases is not yet demonstrated. 



Copper-sulfate treatment. — This is the oldest effective 

 treatment of cereal seeds. It has, however, on account of its 

 greater cost and the larger injury done to the seed, in the 

 main been superseded by formalin methods. It is effective 

 against the same smuts for which formalin is used, but is 

 recommended only where there is heavy soil infestation. A 

 solution of 1 pound of copper sulfate and 1 pound of common 

 salt to 5 or 10 gallons of water is used, and the seed either 

 soaked, sprinkled, or dipped. Treatment should be com- 

 pleted by dipping or sprinkling with milk of lime (1 pound of 

 quicklime to 10 gallons of water). 



The hot-water treatment ^-^ is employed for those smuts in 

 which the fungus is within the seed, not superficial. There 

 are three forms: 1, the short treatment; 2, the modified hot- 

 water treatment; 3, the long treatment or pasteurization. 

 The first consists, in general, in subjecting the seed to water 

 at a temperature ranging from 52° C. (120° F.) to 61° C. 

 (142° F.) for 10 to 15 minutes. It is of use in only those 



