712 
Journal of Agricultural Research 
Vol. XXIV. No. 8 
HELMINTHOSPORIUM TURCICUM PASSERINI 
Helminthosporium inconspicuum Cooke & Ellis 1878, in Grevillea, v, 6, p. 88-89. 
The disease of maize commonly known as “leaf blight’’ and less fre¬ 
quently as “white blast” is found in many regions of the globe in which 
this important cereal is cultivated. It appears to have been first ob¬ 
served by Passerini {105) in 1876, who noted its occurrence in Italy 
under the term “nebbia” and attributed it to a species of Ilelniintho- 
sporium, which he named H. turcicum. Two years later, Cooke and 
Ellis (24) described a form from New Jersey as H. inconspicuum, similarly 
thriving on maize. Although the descriptions of the American and 
Italian forms are not especially similar, there appears to be good reason 
to believe that they were based on material belonging to the same species. 
In the account given by Cooke and Ellis, the American fungus is very 
briefly described: 
Tenuissime effusum. Hyphis elongatis, septatis, nodulosis, pallidebninneis. 
Sporis lanceolatis, S ‘^5 septatis; episporio tenui. 
On Zea mays. 
Effused, but so thinly as not to be visible to the naked eye. Spores 0.08 to 0.12 
by 0.02 mm., at first with the endochrome divided, at length septate. 
The parts of the statement regarding the number of septa, the visibility 
of the fructifications, and the alleged division of the endochrome previous 
to the division of the spore can scarcely be regarded as altogeAer cor¬ 
rect, either for the parasite causing leaf blight or for Helminthosporium 
sativum, which, as has been pointed out in another connection, is known 
to occur on the organs of mature com plants. The parts regarding the 
description of the sporophore, the shape and measurements of the spore, 
as well as the figure of tihe latter that accompanies the text, on the othei 
hand, might apply about equally well to both species. Indeed the 
chief reason for regarding the description given by Cooke and Ellis as 
applying to the le^ blight fungus is not found in the single distinctive 
characterization—that concerning the thin epispore—^but rather in the 
abundance of the parasite in the general region in which Ellis made his 
collections. In 1881, Peck (107) recorded the leaf blight disease in 
New York, although, as has been stated in another connection, his 
description of the fungus is less applicable to the parasite under con¬ 
sideration than to H, sativum. The trouble again was found in New 
York by Stewart (144) in 1896. In 1889 Thaxter {149) observed a 
serious outbreak of the disease in Connecticut, where 14 years later 
Clinton {21) found it again doing considerable damage. In 1903 the 
malady was quite destructive also in Delaware, according to the account 
given by C. A. Smith (rjj). During the same season Stone and Monahan 
{145) noted its abundance in Massachusetts; and Orton {99) found it 
very general also in eastern Pennsylvania and New Jersey. Since then 
it has been reported repeatedly not only from the Middle Atlantic and 
New England States, but from other sections as well, the records of the 
Plant Disease Survey indicating its presence in nearly every State east 
and in some of the States immediately west of the Mississippi River. 
Stevenson and Rose {143) reported leaf blight of com as occurring 
in Porto Rico, Robinson {122) in 19 ii observed the disease in the 
Philippines, where it has been noted also since then by Baker (5) as well 
as by Reinking {117), Tryon {133) records an outbreak of the trouble 
in New South Wales in the season of 1886 so destructive as to attract 
