18 



EXPERIMENTS WITH THE SORGHUM SMUTS. 



BY W. A. KELLERMAN, OHIO STATE UNIVERSITY. 



Some experiments in smut infection with the two 

 sorghum smuts, Ustilago reiliana and Ustilago sorghi, 

 have been for some time carried on both in the green 

 house and in the field. In addition to the seed infection 

 experiments, tests were also made in the field during 

 the past season as to the efiicienc_v of hot water as a 

 fungicide for the latter species. 



The illustrations herewith presented show 

 sorghum plants infected with Ustilago reiliana. No. 1 

 was infected and planted two 3'ears ago. No. 2 was 

 infected and planted one year ago. Both pots of 

 plants have been growing continuously in the green- 

 house, and the stalks not wholly blighted by the smut 

 have from time to time produced perfect seed. Similar 

 infection experiments were previousl\^ carried on and 

 have been reported elsewhere in print. My experi- 

 ments in the field were not so successful as the green- 

 house experiments. I used maize of several varieties as 

 well as sorghum, but succeeded in obtaining only two 

 cases of infection. These were both of popcorn. The 

 previous year showed as little success — though in each 

 case I used a qaantity of the smut which was ap- 

 parently sound. Some of it was several years old, yet 

 spores grown the previous season Avere also used. But 

 it has been abundantly and conclusively shown that 

 infection of sorghum plants take place in this manner — 

 a fact of importance in connection with the application 

 of fungicides. This smut had been reported for 

 Kansas, New Jersey and Ohio. In Kansas it occurs on 

 maize as well as on sorghum. The same is the case in 

 southern Europe. 



It is also known, from experiments I have previ- 

 ously carried on, that Ustilago sorghi also infects the 



