A STUDY OF SOME IMPERFECT FUNGI ISOLATED FROM 
WHEAT, OAT, AND BARLEY PLANTS 
By Edward C. Johnson, 
Formerly Pathologist in Charge of Cereal-Disease Investigations , 
Bureau of Plant Industry 
INTRODUCTION 
Of the imperfect fungi, many are parasitic on cereals wherever climatic 
conditions favor their development. They occur as scab on the heads, 
as leaf spots, and as infections in the culms and roots. Usually one or 
more species are present in the roots and culms of stunted plants, more 
particularly where some one cereal crop has been grown year after year 
on the same land. A study of the fungi occurring on wheat, oats, and 
barley, with particular reference to their pathogenicity, is therefore of 
much economic importance. 
Such a study was begun in the cereal-disease laboratory of the Office 
of Grain Investigations of the Department of Agriculture in 1910. Species 
of imperfect fungi were isolated from wheat, oats, and barley obtained 
from various parts of the country. Helminthosporiums, Altemarias, 
Cladosporiums, and Fusariums were obtained. They were secured from 
leaf spots or from the lower nodes, root crowns, or roots of more or less 
stunted plants. In many cases they were obtained pure from fresh sporu- 
lating material on leaves and stems. In other cases they were obtained 
from the nodes, root crowns, and roots by sterilizing these parts exter¬ 
nally in a 1 to 1,000 solution of mercuric chlorid, washing them in several 
changes of sterile water, and incubating them in moist chambers. After 
incubation for three to five days at a temperature of 72 0 to 77 0 F., sporu- 
lating myceliums were usually obtained. Plate cultures were then made 
and the fungi present isolated in pure cultures and propagated. On corn- 
meal agar, corn meal, and potato cylinders most of them grew and sporu- 
lated profusely. 
Pure cultures were obtained and grown and the identity determined 
as Fusarium culmorum W. G. Sm., Helminthosporium gramineum Rabh., 
Cladosporium gramineum Cda., and a species of Altemaria. The deter¬ 
mination of Fusarium culmorum was made by Dr. H. W. Wollenweber, 
of the Bureau of Plant Industry; the other determinations were made 
by the writer. Helminthosporium gramineum was isolated from the 
lower parts of the culms of stunted wheat plants growing on land con¬ 
tinuously cropped to wheat at the Minnesota Agricultural Experi¬ 
ment Station, and from wheat leaves and barley leaves at the same 
Journal of Agricultural Research, 
Dept, of Agriculture, Washington, D. C. 
(47s) 
Vol. I, No. 6 
Mar. 25, 1914 
O-iS 
