338 BULLETIN No. 189 [June, 



3,000 cuttings, 2,000 plants, and 7,000 seedlings of various kinds. With 

 these, comparisons were made of about forty-five strains of Rhizoctonia. 

 A large number of the strains used in these experiments were iso- 

 lated by the writer from the various hosts found infected with Rhizoc- 

 tonia in this vicinity. Other strains were obtained from various in- 

 vestigators thruout the country. Below is presented a list of the strains 

 used and the source of each. 



Alfalfa. A Khizoctonia culture froni alfalfa was received from Dr. C. W. 

 Edgerton, Baton Rouge, Louisiana, November 12, 1912. It was originally ob- 

 tained by Dr. Edgerton in May, 1910, from alfalfa seedlings. 



Alternanthera E.A.C. A culture of Rhizoctonia was isolated from infected 

 alternanthera cuttings found in the floricultural greenhouses in the fall of 1912. 



Alternanthera E.A.F. This strain was obtained at the same time as the 

 preceding, from mature alternanthera plants in the field. 



Amaranthus. In August, 1913, Mr. W. H. Burkholder, of Cornell University, 

 contributed several specimens of Amaranthus retro flexus infected with Rhizoc- 

 tonia, from Irving, New York. The stems were covered with the immature, gray, 

 felt-like mycelium of the Corticium stage. Scrapings of the hymenial layer of 

 this stage yielded pure cultures of Rhizoctonia in every case. 



Aster. Early in 1913, Dr. F. A. Wolf sent to the writer a culture of Rhizoc- 

 tonia which was the cause of the damping-off of China aster seedlings in flats 

 in the greenhouse at Auburn, Alabama. 



Bean. A transfer of a culture of Rhizoctonia from bean was obtained in 

 December, 1912, from Dr. J. T. Barrett, of this university. He in turn had re- 

 ceived it from Dr. M. F. Barrus, of Cornell University, about 1910. 



Beet. A culture of Rhizoctonia was obtained from young seedlings of the 

 garden beet found damping oft' in the vegetable-gardening greenhouses, July 10. 

 1913. 



Begonia. The strain from begonia was isolated by Mr. Anderson from cut- 

 tings found damping off in the floricultural greenhouses in the fall of 1911. 



Carnation. During the reason of 1911-12, Mr. Anderson isolated Rhizoctonia 

 from a number of carnation plants received from different sources, and during 

 1912-13 and 1913-14 the work was continued by the author, so that a comparison 

 of a large number of cultures from diseased plants obtained from various localities 

 was possible. The strains used are given below. 



' ' Carnation R.K. ' ' : Isolated by Mr. Anderson from diseased carnation 

 plants obtained at Urbana, Illinois, in October, 1911. 



"Carnation R.O.": Culture isolated by Mr. Anderson in the fall of 1911, 

 at Urbana. 



" Carnation R.H. " : Culture isolated from a diseased plant in the floricul- 

 tural greenhouses in the fall of 1911 by Mr. Anderson. 



' ' Carnation R.S. ' ' : Isolated from diseased plants received from Kankakee, 

 Illinois, by Mr. Anderson, October 25, 1911. 



' * Carnation R. 2 " : Culture reisolated by Mr. Anderson from infected cut- 

 tings in sterilized soil in the spring of 1912. 



"Carnation R.F.": Isolated from diseased carnation plants gathered in the 

 field in the horticultural grounds, July 24, 1912. 



' ' Carnation R.M.2 ' ' : Isolated from a White Enchantress plant in one of 

 the floricultural greenhouses during September, 1912. 



"Carnation R. 107": Obtained from a plant in the floricultural greenhouses, 

 (September 7, 1912. 



' ' Carnation R.F.2 ' ' : Culture obtained from a diseased plant in the field 

 during the summer of 1913. 



"Carnation R. 121-5": A reisolation of Rhizoctonia was obtained on De- 

 cember 3, 1912, from a diseased plant in one of the inoculated sections of the 

 greenhouse. 



Carrot. The strain of Rhizoctonia from carrot used in this work was ob- 

 tained by Mr. Anderson from Cornell University in 1911. Nothing is known of 

 the origin of the culture. 



