'MM 



l-TMil AND lTN-<;irlI)KS 



to the field with the manure, finally infecting the plants 

 but this has not yet been definitely determined. The 

 observations of Kuhn indicate that the germinating 

 mycelium penetrates the very young corn plant at the 

 root node and the first formed joint, and that after the 

 corn gets well started the danger of infection by smut is 

 passed. It has generally been supposed that the sp< 

 adhered to the seed, and caused infection; but recent 

 experiments at the Kansas Experiment Station in 

 ~hich corn kernels were rolled in smut spores, without 



increasing the amount of 

 smut in the resulting crop 

 throw so much doubt upon 

 this assumption that Pro- 

 fessor Kellerman thinks that 

 "further investigation is 

 necessary in order to deter- 

 mine the mode of infection,"' 

 adding that this is "a point 

 that must be settled before 

 we can hope to employ ra- 

 tional methods for the pre- 

 vention of this annoying and destructive pest." 



It seems pretty well proven, however, that the smut 

 can exist in the soil from year to year, and infect suc- 

 ceeding crops. The following experience, related by 

 Professor Bessey, as occurring in Iowa a few years ago, 

 shows this: "One season a piece of land, including 

 about three-fourths of an acre, was planted with sweet 

 corn for table use. Some smut made its appearanc* 

 first year, but it was all allowed to fall back to the 

 ground. None of the stalks were removed, but all were 

 plowed under, and the second season the ground was 

 again planted with sweet corn, for table use as before. 

 This time the smut was remarkably abundant, but again 

 it was all allowed to fall upon the ground, and was 



FIG. 85. SMUT SPORES GERMINAT- 

 ING AND FORMING SPORIDIA. 



