6 Research Bulletin No. p 



The credit of Inst demonstrating experimentally the relation of 

 Fusarium spp. to certain plant wilts belongs to Smith (34), who 

 found a Fusarium responsible for watermelon wilt. Smith and 

 Swingle (35) reported a potato wilt and tuber rot which they 

 considered due to a Fusarium which they called F. oxysporum. 

 They considered this organism identical with / ; . solaui of PlZZIGONI 

 and Wehmer, and used the oldest name available, F. oxysporum 

 (Schlechtendahl, 1824) : however, they reported no experimental 

 inoculations. Pethybeidge and Bowers 1 28 ) reported a dry rot 

 due to F. solani, and Longman (22 i also reported a dry rot due 

 ti i a Fusarium. 



Many pathologists and mycologists entertained considerable 

 doubt as to the parasitic nature of Fusarium spp., while others were 

 quite convinced of their parasitic nature. Soratjer (36) was quite 

 positive in his decision, while Massee (25) wavered. LlNDAU l 18 I 

 remained skeptical and referred to the F . oxysporum of Smith 

 and Swingle as a "Mischart." Duggar (10) was quite positive 

 in his decision. Much of this difference of opinion undoubtedly 

 was due to the confusion that prevailed as to the status of F. solaui. 

 F. oxysporum, and the genus in general, since no basis for extended 

 morphological study of the genus had been established, and even the 

 genus itself had not been sharply denned. Massee (25) considered 

 / ; . solani to be the conidial form of Nectria solaui; while Reinke 

 and Bertholdt i 30 i considered it the conidial form of Hypomyces 

 solani. Lounsbury (23) tried to arbitrate the matter by suggest- 

 ing that F. solani and F. oxysporum are one and the conidial stage 

 of Nectria solani. Appel and WOLLENWEBER (5) published a 

 monograph in which they denned the genus and brought some 

 order into the chaos of species. Among other radical changes they 

 dropped F. oxysporum and established F. orthoceras in its place. 

 Manns (24) demonstrated by experimental inoculation that a 

 Fusarium, which he designated ( following Smith and Swingle) as 

 F. oxysporum, could produce tuber rot and wilt. He made no 

 morphological studies, however, and undoubtedly had not had 

 access to Appel and Wollenweber's monograph. 



Jamieson and Wollenweber (16) published an account of a 

 drv rot of tubers induced by a Fusarium which they described as a 



