Oct. i. i 9 2o Fusarium-Blight (Scab) of Wheat and Other Cereals 1 5 



of 1 91 8 it was frequently isolated from cornstalks fed to the cattle on the 

 University farm and from cornstalks that had been taken out into the 

 fields with the manure or for cattle feeding. 



The mycelium of the organism present in infected straw and heads 

 of wheat, rye, and barley when stored in the laboratory at room tem- 

 perature and moisture was found viable after 12 months. In the 

 infected seed it remains viable even after the second year. 



The undeveloped perithecia of the organism, which are often found in the 

 fall on the straw and heads of the cereal crops, on cornstalks and sheaths, 

 and on many grasses, are another form in which this organism over- 

 winters. In the spring these perithecia mature and form numerous 

 ascospores, which are later liberated from the perithecia and carried to 

 the various susceptible hosts. Mature ascospores in perithecia on wheat 

 heads and cornstalks preserve their viability for over 8 months when 

 kept in the laboratory at room temperature and moisture. 



DESCRIPTION OF CAUSAL ORGANISM 

 TAXONOMY 



The chief cause of headblight and one of the chief causes of rootrot 

 of the cereal crops in the United States is Gibber ella saubinetii (Mont.) 

 Sacc. The following is a list of synonyms : 



Gibberella saubinetii (D. and M.) S., 1879, in Michelia, v. 1, p. 513. 



Gibbera saubinetii Mont., 1856, Syll. Gen. Spec. Crypt., p. 252. 



Botryospkaeria saubinetii (Mont.) Niessl, 1872, in Verhandl. Naturf. 

 Ver. Briinn, Bd. 10, p. 195, pi. 4, fig. 29. 



Fusarium graminearum Schwabe, 1839, Fl. anhalt, v. 2, p. 285, pi. 6, 

 fig. 7; Sacc. Syll. v. 22, p. 1483-1484, 1913. 



Gibbera pulicaris (Fr.) f. zeae maydis, Rehm: Ascomyceten 381. From 

 New Jersey, 8, 1875, J. B. Ellis. 



Fusarium roseum Autorum. 



Fusarium tropicalis Rehm, 1898, in Hedwigia, Bd. 37, p. 194. Is 

 probably a synonym of Gibberella saubinetii according to Wollenweber 



{12). 



Gibberella tritici P. Henn., 1902, in Hedwigia, Bd. 41, p. 301. 

 Fusarium rostratum App. and Wollenw., 1910, in Arb. K. Biol. Anst. 

 Land u. Forstw., Bd. 8, p. 30. 



MORPHOLOGY 



Perithecial stage. — The following description of the perfect stage 

 of this organism, given by Wollenweber (12), is adequate: 



Diagnosis. — Perithecial stage : Perithecia scattered or gregarious, ovoid to subcorneal , 

 free on the surface of the host as well as embedded in mycelium, or on a tubercular 

 plectenchymatic stroma, which may either push in sphaerostilbe-like bodies through 



