8 
Research Bulletin No. I 
vious wounding of the tubers. From 80 to 86 per cent of rotted 
tubers were found to have been previously wounded to some 
extent. 
Duggar 1909 in his discussion of the "Dry Rot of Potatoes'' 
(p. 317) says: "It is very probable that many of the diseases 
described under the name of dry rot, end rot, bundle blighting,* 
etc., are due to the fungus here discussed. Smith and Swingle 
have, by careful cultural and inoculation experiments, demon- 
strated the causal connection of a Fusarium with these types of 
disease, and they have taken as the name of the species here 
discussed the earliest described species of Fusarium associated 
with such diseases, namely the one given above, and they would 
regard as probably synonymous with this species half a dozen 
or more names subsequently applied to fungi described as pro 
during more or less similar types of disease in the potato." 
Lounsbury 1909 has described and illustrated a dry rot of the 
potato tuber found in Cape Colony as caused by Nectria solani. 
He says (p. 42) : "The infection is introduced into the soil with 
diseased tubers and it remains there from season to season, 
so that a crop from perfectly healthy seed may get infected if 
grown on land that previously bore an affected crop. The 
disease generally enters at the stem end. The fungus de- 
velops most rapidly in the "vascular ring." From his refer- 
ence to the "wilting" symptoms shown by affected vines and 
the last one of his figures it appears likely that he has con- 
fused the tuber dry rot and the Fusarium wilt referred to by 
various American plant pathologists. 
Jack 1910 has described a gall of the potato tuber from 
Rhodesia due to a species of Heterodcra with which is frequently 
associated a form of dry rot. He says (p. 1533) : "Their 
presence in numbers is followed by decay in the tissues and 
frequently by the wilting of the infested plant. In the case of 
potatoes the infested tubers yield very readily to the attack of 
the common dry rot (Fusarium solani)." 
Morse 1910 describing "Fusarium Dry Rot" (pp. 6-7) says: 
"The first symptoms are nearly always at the stem end, in the 
form of a brownish or blackened ring a short distance below the 
surface. At this stage the tuber may appear perfectly sound 
and healthy externally. Later there is a general discoloration 
of the flesh and a decided shrinkage of the tuber. The skin 
becomes wrinkled around the stem end, and the tuber becomes 
very light and often nearly as hard as wood. Tnfected potatoes 
may appear perfectly sound when placed in storage, and come out 
as described above." 
"When this disease is suspected the stem end of the tuber 
* Probably refers to "bundle Warlcenincj." 
