.1 Dry Rot of the Irish Potato Tuber 
1 
potatoes which they claimed was due to Fusarium oxysporum. 
Subsequent authors in their discussion of similar symptoms of 
potato diseases have largely been guided by and often have 
merely repeated, without verification, the conclusions of Smith 
and Swingle. 
What appears to be the same disease is described by anon. 
1906 from England under the name "Winter Rot" and is claimed 
to be due to JVectria solani — an organism often mentioned in the 
literature as the "perfect" stage of Fusarium solani. This author 
says (pp. 739-740) : "It attacks stored potatoes, and is always 
present to some extent, but as a rule only reaches the propor- 
tions of an epidemic during hot, dry seasons. The tubers only 
arc 1 attacked, and inoculation, through spores present in the soil, 
takes place when the tubers are young; but, as a rule, there is 
no obvious disease present when the tubers are lifted, although 
the mycelium of the fungus is present in the tissues. During the 
following season the most perfect stage of the fungus, in the 
form of minute crimson-red points, develops on the skin of the 
diseased tubers." 
Norton 1906 referred (p. 67) to a "dry-rot" as caused by 
Fusarium oxysporum in the following words: "The disease is 
indicated by the lighter colored and more or less rolled up leaves. 
When dug the potatoes may appear sound, but internally show 
black or brown streaks, and later are destroyed at least at one 
end by the dry rot." 
Morse 1908 says (p. 2) : "Another disease of the stem and 
tuber which is usually designated as the Fusarium dry rot caused 
by the fungus Fusarium oxysporum Schlecht. has been found for 
the first time in Maine during the past summer. It is well known 
that this disease, and it is probable that black leg as well, is dis 
seminated by means of seed tubers from infected fields." 
Pethybridge and Bowers 1908 have described a dry rot of the 
potato tuber from Ireland where they say it first appeared in 
1902 on the "Snowdrop" potato. They say (p. 548) : "They were 
fairly firm to the touch, but more or less shrivelled, with the 
skin contracted into wavy wrinkles. At various points on the 
tubers the skins were broken through by fungus pustules. These 
were whitish on the surface; but on gently rubbing them the 
base of the pustule was seen to be of a blue color. On standing 
for some time, especially in the light, the surface of the pustules 
changed from whitish to a salmon-pink; on the less well- 
illuminated undersides of the tubers and on those in the dark 
the pustules remained for a long time whitish blue." 
They ascribed this rotting to the fungus Fusarium solani 
Saccardo and emphasized the relationship of the rotting to pre 
