JOURNAL OF AtMCDLTTRAL RESEARCH 
DEPARTMENT OF AGRICULTURE 
Vol. V Washington, D. C., November i, 1915 No. 5 
SOME POTATO TUBER-ROTS CAUSED BY SPECIES OF 
FUSARIUM 
By C. W. Carpenter, 1 
Scientific Assistant , Cotton and Truck Disease Investigations , 
Bureau of Plant Industry 
INTRODUCTION 
Deterioration of tubers of the Irish potato (Solanum tuberosum) is 
induced by a variety of causes. Economically the most important of 
these are the organisms Phytophthora infestans t Fusarium spp., bacteria, 
and miscellaneous fungi, including Rhizopus nigricans . 
Phytophthora infestans , which is somewhat restricted to the northeast¬ 
ern part of the country, does more or less damage each year, and occa¬ 
sionally in epidemic form causes tremendous losses. Exclusive of P. 
infestans , however, species of Fusarium are undoubtedly the most impor¬ 
tant causes of tuber decay. Though never occurring in epidemic form 
with losses comparable to those of late-blight, they are present wherever 
potatoes are grown, taking their quota of the crop both in the field and 
in storage. 
Several species of the genus Fusarium Link have been described as 
causes of tuber-rots of Solanum tuberosum (Clinton, 3; Pizzigoni, 12; 
Wehmer, 15; Smith and Swingle, 14; Pethybridge and Bowers, 11; 
Longman, 6; Manns, 7)? In most cases prior to 1912 F . solani (Mart.) 
Sacc. or some species thought to be a synonym of it is given as the causal 
organism. Until recently the chaotic condition of the genus Fusarium 
has precluded careful work with clearly defined species. 
1 Having been associated with Dr. H. W. Wollenweber, of the Bureau of Plant Industry, during the 
past two years, the writer has enjoyed the privilege of personal work with the species and strains cultivated 
during this period in connection with his monographic study of the genus Fusarium. Any attempt to 
work with the species of this form genus emphasizes the necessity of completing such studies. Owing to 
Dr. Wollenweber’s absence during the preparation and publication of this paper, he is not responsible 
for the subject matter. It is regretted that his criticism of the results is lacking, particularly as the data 
obtained force the author to conclusions which differ somewhat from Dr. Wollenweber’s published opinions. 
2 Reference is made by number to “ Literature cited,” pp. 208-209. 
For a list of the more important references to potato studies, see the following: Appel, Otto. Beitrage 
zur Kenntnis der Kartoffelpflanze und ihre Krankheiten. I. In Arb. K. Biol. Anst. Land u. Forstw., 
Bd. s. Heft 7, p. 415-435* 1907. 
Journal of Agricultural Research, 
Dept, of Agriculture, Washington, D. C. 
am 
(183) 
Vol. V, No. 5 
Nov. 1,1915 
G—62 
