THE STERILE FUNGUS RHIZOCTONIA AS A 

 CAUSE OF PLANT DISEASES IN AMERICA * 



B. M. DUGGAR AND F. C. StB1WAB.«, 



SUMMARY. 



RJiizodonia is a name given to certain sterile fungi occurring 

 upon the subterranean parts of plants. Botanical literature 

 contains numerous accounts of plant diseases in Europe caused 

 by RMzoctonia; but little has been written on such diseases in 

 America. 



Finding that Rhizoctonia is common on various cultivated 

 plants in America the authors have undertaken an exhaustive 

 study of the genus. The bulletin is a preliminary report. It 

 contains accounts of the discovery of the fungus on about 30 

 species of cultivated plants in the United States. 



Rhizoctonia is the cause of a destructive root-rot of the sugar 

 beet, a destructive stem-rot of the carnation, a leaf-rot of green- 

 house lettuce, a leaf-rot of ornamental asparagus and a root-rot 

 of the carrot; and is of common occurrence on stems and tubers 

 of the potato. It is a frequent cause of damping-off of various 

 seedling plants, such as beet, carnation, celery, lettuce, cab- 

 bage, etc. It is also the suspected cause of disease in the bean, 

 rhubarb, cotton, and some other plants. Further observations* 

 will probably show that many other plants are infested by it. 



♦Repriut of Bulletin No, 186. 



as 



