1900] Kellerman — Sorghum Smut 9 



A F0LIIC0L0U8 F'ORM OF SORGHUM SMUT AND NOTES 

 ON INFECTION EXPERIMENTS. 



W. A. Kellebman. 



(Plate 2.) 



On January 1st, 1900, several pots in the Botanical greenhouse 

 of tlie Ohio State University were planted to sorghum, KafRr corn, 

 maize, sweet-corn and pop-corn. The seeds were pi'eviously 

 moistened and mixed with a large quantity of head-smut of sorghum 

 taken from smutted sorghum jDlants also from maize infected with 

 the same fungus. This species was named Ustilago reiliana by 

 Kiihn in 1868 from specimens collected in Egypt. 



The plants developed rapidly and normally, though the stems 

 were slender and did not reach the normal height. The panicles 

 appeared early and only in a comparatively few cases showed in- 

 fection. 



In one case an anomalous specimen appeared, namely, a sweet 

 corn plant with the upper leaves as well as the panicle infected. 

 This form therefore differs from the type in being in part foliicolous 

 and may be designated as Ustilago (Cmtractia*) reiliana forma 

 folUcola nov. for. Figures 1 and 2, Plate 2, show the appearance of 

 the infected plant, the one representing an earlier and the other a 

 later stage of the emergence of the smut mass. 



It may be remarked further that I have repeatedly tried seed 

 inoculation experiments, mostly in the greenhouse but also 

 occasionally in the field. 



In the latter case in the summer of 1900, 1 obtained from a plot of 

 many hundred stalks including field-corn, sweet-corn, pop-corn, 

 sorghum, Kaffir corn and broom corn only three cases of smutted 

 plants. These were of sweet corn, both the tassel and ear being 

 affected. The previous year about the same per cent of successful 

 inoculations were obtained. But in the greenhouse the experiments 

 have uniformally resulted in the production of a considerable 

 number of smutted stalks of sorghum and occasionally an infected 

 plant of maize. These have for the most part been reported in print, 

 the first account appearing in Bulletin No. 23, Kansas Experiment 

 Station, in the year 1891. 



I have now growing in the botanical greenhouse three sets of 

 sorghum plants raised from seeds planted January 1, 1898, Janu- 

 ary 1, 1899, ancl January 1, 1900. Only the plants have been retained 

 which showed successful inoculation experiments. They have been 

 shifted to larger pots from time to time, but the plants make only a 



••'Mr. G. P. Clinton regards this fungus as a Cintractia rather than an Ustilago. 



