1915] 



DUGGAR RHIZOCTONIA CROCORUM AND R. SOLANI 411 



Australia, Asia, or Africa has come to my attention, yet the 

 distribution of alfalfa growing throughout the world and the 

 frequent interchange of seed might suggest that the distribu- 

 tion of the organism may be found to be much more general 

 than is reported. It should be mentioned that Shaw ('13) 

 reports the fungus from India, but he has obviously been 

 misled regarding the fungus concerned, as will be shown 

 later. 



Du Hamel represented the violet root fungus as prevailing 

 under a variety of soil conditions, but electing dry, gravelly, 

 and acid localities. It is reported by the brothers Tulasne 

 that while wet weather may give the fungus an advantage, 

 still it is found in the driest situations permitting crop 

 growth. In central Germany Kiihn's studies led to the sug- 

 gestion that on root crops and potatoes it is found more fre- 

 quently in low and stagnant places. Frank and Comes con- 

 cur in this view. The writer was able to observe the fungus 

 in the vicinity of Munich in 1905 and in the fields examined, 

 it was found under conditions which appeared to be favor- 

 able for the growth of the host. The very general occurrence 

 of the fungus in southern Europe, especially in southern 

 France and Italy, would seem to indicate that excessive 

 moisture is not always an important factor. At the same 

 time the fungus is of frequent occurrence in Scandinavia. It 

 is not reported as one of the more serious diseases of any 

 host in England. In the more humid regions of the eastern 

 United States it is unknown, while two of the localities from 

 which it has been reported are regions of lower humidity and 

 lesser rainfall. 



HOST PLANTS AND GENERAL SYMPTOMS 



There is every reason to believe that the number of host 

 plants for Rhizoctonia Crocorum is much greater than has 

 been reported. The fungus has been observed upon many 

 economic plants ; and it has been reported in the agricultural 

 press of Europe as occurring upon a variety of weeds, but 

 these references are not always definite. Eriksson has made 

 some observations regarding the plants attacked when culti- 



