306 BULLETIN No. 189 [June, 



DISTRIBUTION OF RHIZOCTONIA IN CANADA 



In a letter to the writer, Dr. H. T. Giissow of the Central Experi- 

 mental Farm, Ottawa, Canada, stated that he had observed Rhi- 

 zoctonia Solani on potato, pea, sweet pea, and aster. That the stem 

 rot of carnation also occurs in Canada is shown in a paper read by 

 John Morgan of Hamilton, Ontario, before the Canadian Horticul- 

 tural Association at Guelph, in August, 1906. 



DISTRIBUTION OF RHIZOCTONf A IN SOUTH AMERICA AND 

 THE WEST INDIES 



The following list of plants reported as susceptible to R. Solani 

 in South America and the West Indies, with character of injury, has 

 been compiled from Cook's 19 Diseases of Tropical Plants: 



Bean Damping-off, dry rot of stem, and pod rot 



Beet Boot disease 



Cotton Damping-off and sore shin 



Cucumber Damping-off 



Lettuce Damping-off 



Melon Damping-off 



Nursery stock Damping-off 



Pea Boot and stem rot 



Potato On stem and tubers 



Seedlings Damping-off 



Sweet potato Boot rot 



Tobacco Seed-bed rot 



Tomato Rosette and fruit rot 



DISTRIBUTION OF RHIZOCTONIA IN EUROPE 



Despite the wide distribution of Rhizoctonia in Europe, the nomen- 

 clature of the species is in a very confused state. Some writers under- 

 stand Rhizoctonia Crocorum (Pers.) DC. to include several species, 

 while others treat it as a separate species including forms with a rich 

 violet mycelium. This uncertainty extends to the other common species 

 of Rhizoctonia, so that the European literature on the subject offers 

 many difficulties. Another fact which adds to the confusion is that 

 both Rhizoctonia Solani and Rhizoctonia Crocorum attack potato 

 stems and tubers, and while the symptoms caused by the two fungi can 

 be easily distinguished from one another in the field, it is another mat- 

 ter to differentiate between them in literature. 



A partial list of the hosts in Europe which are attacked by Rhizoc- 

 tonia is given below to show the extent of the distribution of this fun- 

 gus. Only the more important references are mentioned. 



Austria Hungary. Rhizoctonia was first reported in Austria Hun- 

 gary in 1875 on potato. Later R. Crocorum was found on sugar beet, 

 potato and lucerne, and R. Solani (Corticium vagum), on potato. 



