334 



THE FARMERS HANDBOOK. 



The plant may also become affected with Smut as result of infection from 

 soil which has previously grown smutty crops. This, however, is rela- 

 tively rare. The chief cause of Smut is the sowing of seed which has 

 healthy spores adhering to it. It follows, therefore, that if the vitality of 

 these spores can be destroyed, or if the plants resulting from the germina- 

 tion of the spores are destroyed, the grain crop will be " clean." Methods 

 have been introduced for successfully destroying the vitality of the spores, 



.<<• 



Fig. 3. — Part of " Brush " of Wheat Grain. 

 This illustration shows spores caught by the hairs of the brush, and affords a comparison of the size of 



the spores and hairs. 



but no practical method has yet been devised for killing the smut plants 

 after they have germinated. Occasionally, as in the case of self-sown crops, 

 the natural conditions prevailing at the time the seed is planted are the 

 cause of a " clean " crop being produced from untreated smutted seed ; but 

 to depend upon this chance method of obtaining clean crops is very unwise 

 and likely to lead to disappointment. It is far wiser and more business- 

 like to destroy the vitality of the spores, and thus prevent them growing. 



