204 



FUNGI AXD FUXGICIDES 



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 spores 

 adhered to the seed, and caused infection ; bnt 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 

 tills assumption tliat Pro- 

 fessor Kellerman thinks that 



'^further 

 necessarv in order 



investigation 



IS 



to deter- 

 mine the mode of infection,'' 

 adding that this is *' a point 

 that must be settled before 



FIG. 85. SMUT SPORES GEB.nxAT- ^^ ^au hopB to cmploy ra- 

 iNG AND FORMING spoRiDiA. tioual mcthods for the pre- 

 vention of tills annoying and destructive pest." 



It seems pretty well proven, however, that the smut 

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

 ceeding crops. The following experience, related by 

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



shows this 



a 



One season a i^iece of land, including 



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

 corn for table use. Some smut made its appearance the 

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

 ground. Kone 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 



