•258 The Ohio Naturalist. [Vol. II, No. 6, 



SMUT INFECTION EXPERIMENTS. 



W. A. Kellerman and O. E. Jennings. 



Experiments were undertaken during the summer of 1901 to 

 test the comparative susceptibility of maize (dent corn, pop 

 corn, and sweet corn) and sorghum (Saccharins sorghum, Kaffir 

 corn, and broom corn) to the same species of smut found on 

 different hosts. Both the sorghum seed-smut ( Cintractia sorghi) 

 and the head-smut (Cintractia reiHanaj were used. 



Three rows each of dent corn, pop corn, sweet corn, Kaffir 

 corn, sorghum and broom corn were planted. One row of each 

 set of three was planted with untreated seed as a check row. 

 Another row of each set was planted with seed rolled wet in sor- 

 ghum head-smut (Cintractia reiliana) obtained from sorghum. 

 The remaining row of each set was planted with seed rolled in 

 the same species of smut obtained from maize. 



In the same manner Kaffir corn, sorghum and broom corn were 

 used, being treated with the sorghum head-smut (Cintractia sorghi) 

 grown on the two hosts sorghum and broom corn. 



Thorough precautions were taken in treating the .seed and 

 interesting results were expected. Unfortunatel}' severe drouth 

 and abundant chinch-bugs blasted hopes and experiments alike. 

 Only one specimen of Cintractia reiliana was obtained, namely, 

 on pop corn. vSo few stalks infected with Cintractia sorghi were 

 obtained that no conclusions can be drawn. Experiments along 

 these lines are now being carried on in the botanical greenhouse 

 from which some satisfactory results are being obtained and 

 wdiich will be reported later. 



A few stalks of sorghum artificially infected two to three years 

 ago, and still growing, continuously produce infected panicles. 



An illustration of one of the .specimens planted January ist, 

 1899, is here given. This illustrates the fact that infection takes 

 place through the seed, first .shown in 1891.* It also demon- 

 strates that the mycelium, permeating throughout the entire 

 plant, is perennial or at least is coexistent in duration with the 

 host — the latter grown as an annual in our climate, but when 

 protected, as has been the greenhouse specimen, it may continue 

 to live a long while. 



The other ex])eriments, which are enumerated below, relate to 

 corn smut ( Ustilago zeae); the primary object being to determine 

 the effect of mutiJation of the host upon the prevalency of the 

 smut. Work of this kind has been reported by Hitchcock, f 

 Clinton^ and others. 



* Kfllerinan, W, A., Bulktiii Karis. Rxp. Sta. No. 23. 



t Bot. Gaz. 2S, 429, 1.S99, 



X 111. Exp. Sta. Dull 57. March, isoo. 



