Potato Tuber-Rots Caused by Fusarium Spp. 



203 



Table VI. — Results cf the inoculation of different varieties of potato tubers with certain 

 species of Fusarium atid other tuber-inhabiting organisms 



a The respective organism is doubtfully the cause, as in each case wound-parasitic species of Fusarium 

 were isolated in association. See text. 



TAXONOMIC ARRANGEMENT AND DIAGNOSTIC CHARACTERS 

 IMPORTANT ROT-PRODUCING SPECIES OF FUSARIUM 



OF 



FUSARIUM Link 



The sections IMartiella, Elegans, and Discolor provisionally estab- 

 lished by WoUenweber (19, p. 32; 20, p. 28) include the species of Fusa- 

 rium causing tuber-rot known to be economically important. Certain 

 other species — namely, F. ventricosum, F. gibbosum, F. culmorum, 

 F. otihoceras, and F. sitbulatum — reported by WoUenweber (19, 20) as 

 weak wound parasites of the Irish potato are not included in the fol- 

 lowing arrangement of species. F. solani, the type species of the section 

 Martiella, is listed because of its ubiquitous occurrence on potatoes as 

 well as on roots and tubers of other plants. Subnormal conidia of F. 

 coeruleum, F. radicicola, and F. eumartii are easily confused with those 

 of F. solani. The form, size, and septation of normal conidia must be 

 depended upon for differentiation. 



