GRASSES OF IOWA. 229 



methods would be to plant corn which is thoroughly acclimated 

 and such varieties as are least subject to smut. Crop rotation 

 is to be strongly urged. Corn should never follow corn. A 

 year rotation will destroy a large number of the smut spores. 



HEAD SMUT OF SORGHUM (USTILAGO REILIANA, KUEHN). 



In 1875, Kuehn* described a fungus occurring upon sor- 

 ghum, the Ustilago reiliana. Since then this fungus has been 

 found widely distributed on sorghum in Africa, India, China, 

 Egypt, Italy, Hungary, and Germany and in the United States 

 it has been reported from New Jersey, Kansas, Nebraska, Iowa 

 and Wisconsin. A related smut, U. sorglii Unk. has also been 

 found widely scattered in this country, on sorghum. 



Ustilago reiliana attacks the upper part of the plant, especi- 

 ally the ear and staminate flowers, almost destroying it. In 

 but few cases does grain mature. Hitchcock and Norton f state 

 that "The smutted stalks are usually not over half as high as 

 the unsmutted, and in weight are very deficient. Eleven stalks 

 were weighed and averaged 539 grams each, while plants 

 affected with Ustilago maydis from the same field averaged about 

 1,300 grams and healthy plants averaged 1,500 grams or more. 

 So if this smut should ever become abundant in this country, 

 it may seriously change the corn crop as it has the sorghum 

 industry in other parts of the United States. 



In 1876 an Italian botanist, Passerini, J found this fungus 

 upon corn, but until 1895 it had never been reported on sor- 

 ghum. Mr. J. B. S. Norton called attention to its occurrence in 

 Kansas. This disease is not uncommon in Kansas and across 

 the line near Superior, Neb. So far this fungus has not been 



♦Rabenhorsfs Fungi Europ. 19S3. Kuehn. Die Brandformen der Sorghum Arten. 

 Mitth. d. Ver. f. Erdicunde zu Halle. 1877:81, Saccardo. Syll. Fung. 7: 456. 



Kellerman and Swingle. Notes on sorghum smuts. Bull. Kansas Agrl. Exp. Sta. 

 33: Sorghum smuts, Proc. Kan. Academy Sciences. 1890: 158. 



Trelease. Preliminary List of Parasitic Fungi of Wis. 34. 



Webber, H.J. Rusts and Smuts of Nebraska. Bull. Nebr. Agrl. Exp. Sta. 11: 69. 

 Oat. Fl. of Ntb. 74. Rep. Nebr. State Board of Argl. 1889: 



Saccardo. Syll. Fung, 7: 471. 

 tHitchcock and Norton. Bull. Kansas Agrl. Exp. Station. 63: 198. 



Norton, J. B. S. A study of the Kansas Ustilagineffi. Trans. Acad, of Scl. St. Louis 

 7:23). 



Frank. Krankhaiten der Pflanzen. Ill (2 ed.) 



Tubeuf. Pflanzeinkrankheiten. 303. 



Borauer. Pflanzenkrankheiten. 209. 



Comes. Orlttogamla Agraria. 75, 537. 



Saccardo. Syll. Fung. 7: 471. 

 *Passerini. La Nebba dei cereali. 1876. 



Bot. Gazette. 30: 163. 1895. 



