FOOT-ROT DISEASES OF WHEAT IN AMERICA 19 
ECONOMIC IMPORTANCE 
According to Stakman (65) this Helminthosporium foot-rot 
caused as high as 50 per cent damage in wheat fields in certain dis- 
tricts in Minnesota during 1919. She states that in the previous year 
some of the experimental wheat plats on the university farm had to 
be discarded on account of the disease. Christensen (/3) states that 
the disease was reported from practically every important wheat- 
growing county in Minnesota in 1919 and that in some localities it 
caused considerable losses. He states further that in certain cases 
fields of wheat were so badly injured that they were plowed and 
planted to corn, and that in 1921 and 1922 the disease was very 
severe and widespread in wheat, rye, and barley, 10 to 20 per cent 
losses occurring in barley and wheat fields in 1922. Christensen also 
Fic. 3.—Outline map of the United States, showing by means of dots the States in which 
the wheat foot-rot caused by Helminthosporium sativum has been found 
states that H. sativum appears to cause most of the root rotting of 
wheat, barley, and rye in Minnesota. 
Weniger (74) states that in North Dakota as high as 70 per cent 
of the wheat plants in a field may be attacked by Helminthosporium 
sp. She says that for a number of years this disease has caused 
great losses, especially in the durum wheats in the eastern part of 
North Dakota, and that the seedling blight caused by this fungus is 
as severe as that caused by /usartwm sp. Bolley (0) has indicated 
that Helminthosporium sp. is the most common parasite attacking 
the underground parts of wheat plants in North Dakota. 
Raeder (58), working in Idaho, reports a Helminthosporium on 
wheat in several! counties, and according to Haskell and Wood (27) 
Richards reports that a Helminthosporium is associated with a root- 
11 The writer has collected numerous specimens of similariy infected wheat plants from 
fields in North Dakota, and in the cases where Helminthosporium appeared it was always 
found to be H. sativum. 
