CEREAL PESTS PARASITIC FUNGI 529 



fungicides were regarded as particularly unsatisfactory, as 

 they appeared to be incapable of penetrating the rather 

 impervious layers of the grain tissue without seriously 

 injuring the viability of the kernels themselves. Recently, 

 however, some experiments involving the use of copper 

 sulfate and formalin solution, conducted at the Wiscon- 

 sin State Experiment Station, demonstrated the fact that 

 these fungicides are effective in preventing the loose smut 

 of barley, but apparently are much less so in preventing 

 the loose smut of wheat. Jensen's modified hot water 

 treatment, as improved by Kellerman and Swingle, 

 Freeman and Johnson, and Appel and Riehm, seems best 

 suited for the prevention of this type of smut. The 

 essentials of the treatment are as follows : 



The seed is soaked in cold water in tubs, barrels, or vats 

 for 4 or 5 hours. The soaking must not exceed 6 

 hours, nor be less than 4 hours. It is then removed, 

 immediately drained, and treated in hot water. Wheat 

 is treated for 10 minutes at 129 and barley for 13 

 minutes at 126. If the temperature rises to 127 in 

 treating barley, the time of treatment must be reduced 

 to 10 minutes, and to 5 minutes if it rises to 129. 

 Otherwise the seed will be injured. In a similar 

 manner, when treating wheat, if the temperature rises 

 above or falls below 129, the time of treatment must 

 be diminished or increased accordingly. By previously 

 soaking the grain in cold water, thereby causing it to 

 swell slightly, and also causing activity of the latent 

 fungous hyphse, it becomes unnecessary to subject the 

 seed to water of so high a temperature as when treated 

 without the previous soaking, and 'there is, therefore, less 

 danger of injuring its vitality. 



Much time and labor may be saved by treating enough 



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