Pethybridge and Lafferty — Dry-Rot of the Potato Tuber. 195 



killed before the spring, the eyes on the sound parts of the tubers may sprout 

 in a normal way ; but as soon as the disease reaches the shoots, the latter 

 shrink at their bases, their leaves blacken and they die. Nothing definite 

 can be gleaned from Miss Longman's field infection experiments, since the 

 plants in the uninoculated and control plots showed as much disease as those 

 in the inoculated plots. 



From the description and rather poor figures of the fungus given by 

 Miss Longman, and referred to as F. Solani, it is difficult to decide with 

 certainty which species was being dealt with. On the whole, it seems 

 not improbable that the fungus was F. cceruleum. In our work with this 

 species, however, we have failed to observe the " pycnidia " described by 

 Miss Longman. 



In England the dry-rot of the potato (or " Winter-Hot," as it has also been 

 called there) was stated in 1904 by Massee 1 to be caused by Nectria Solani 

 Pers., a name unfortunately adopted subsequently in official publications 

 in that country. This name, however, is not traceable to Persoon, but to 

 Eeinke and Berthold, 2 and when this was realized the revised name Nectria 

 Solani Eeinke and Berthold was substituted in these publications. It is 

 certain, however, that the fungus causing the dry-rot of the potato has 

 nothing whatever to do with Nectria Solani Eeinke and Berthold, an 

 organism which these authors themselves showed to be a mere saprophyte, 

 and to have a conidial form resembling not a Fusarium but a Spicaria. 



Probably led astray by these official but erroneous publications, Eriksson' 

 also wrongly ascribed the dry-rot of the potato to Nectria Solani Eeinke and 

 Berthold, while Evans, 4 probably similarly misled, ascribed it to N. Solani 

 Pers. The same source doubtless accounts for the similar error made by 

 Lounsbury. 5 The kind of evidence presented at a later date by Massee, 6 

 purporting to establish a connexion between Nectria Solani E. and B., 

 Fusarium and various other fungi is quite inadequate to do so, or to show 

 that any of them cause dry-rot. 



1 Massee, G. Some Diseases of the Potato. Gardeners' Chronicle April 24th 1904, 

 p. 257. 



2 Reinke, J., and G. Berthold. Die Zersetzung der Kartoffel durch Pilze. Berlin, 

 1879, p. 39. 



3 Eriksson, J. Hvitrota och Krafta a potatis. Centralanstalten for Jordbruksforsok. 

 Flygblad 8, Feb. 1909. 



4 Evans, I. B. P. Potato Rot (Nectria Solani Pers.). Transvaal Agrie. Journ., vii. 

 25, 1908, p. 04. 



5 Lounsbury, C. P. Dry-rot of the Potato. Agric. Journ. Cape of Good Hope, xxxv. 

 1909, p. 42. 



Massee, G. Diseases of Cultivated Plants and Trees. London, 1910, p. 182. 



2 i2 



