PLANT DISEASES 



275 



spore masses usually find, their way to the soil when 

 they are cut down, or else get into the manure 

 The spores may grow in the 

 manure pile or live over the 

 winter in the soil and in the fol- 

 lowing early summer or spring 

 the threads from the smut 

 spores will again pinch off little 

 spores that are carried by the 

 wind on to the corn plant. Here 

 these spores send out threads 

 which find their way into the 

 corn plant, where they develop 

 rapidly and form another boil. 

 In short, then, the spores live 

 over the winter in the manure 

 pile or soil, and the corn plants 

 are infected in the early sum- 

 mer from these spores that live 

 over. It should be noted that 

 the spores do not live over on 

 the seed ; hence, there is no ne- 

 cessity or use in treating the 

 seed. The only method now FIG. 141. Corn Smut (Usti- 

 known of reducing corn smut is lago maydis} < on an Ear of Cora - 

 to prevent if possible the smut 

 masses from getting either into 

 the soil or the manure pile, 

 and to handle the manure pile 

 wisely; that is, use well-rotted manure, as the spores 

 may have died out in such manure. 



3. The Loose Smuts of Wheat and Barley. These 

 smuts cannot be described in detail here, but are men- 



A few of the kernels near the butt 

 have not been smutted. All the 

 others have been attacked and have 

 increased enormously in size. The 

 enlarged kernels are filled with the 

 smut powder. (Minn. Plant Dis.) 



