.1 Dry Rot of Utc Irish Potato Tuber 
9 
should be cut off and examined for a darkened cinnamon-brown 
discoloration or ring in the tissues when cutting seed." 
Tidswell 1910 described and illustrated a "Dry Rot" of the 
potato from New South Wales which he says is caused by 
Fusarium solani, an organism which he states should more prop- 
erly be called Fusarium oxysporum. The illustration would in- 
dicate that he had to do with a dry rot quite similar to the one 
herein described tho by references to wilting of the tops of the 
plants, blackening of the vascular region, and root infection it 
seems certain that he had confused one or more other diseases 
with the dry rot of the tuber. 
Manns 1911 has described from Ohio a disease called by him 
"the Fusarium blight and dry rot," which he says is caused by 
Fusarium oxysporum. Both his illustrations and the text show 
that the form of potato wilt described by Smith and Swingle 
1904 and the present dry rot have been confused or rather 
united under one common designation. A full discussion of 
Manns' inoculation work will be found under Etiology. 
Jones 1912 describes what he calls "Wilt and Dry Rot.'* His 
conception of the matter is clearly shown by the following state- 
ment (p. 4) : "This is a fungus disease which attacks the roots 
causing the potato tops to wilt and die before full maturity. 
Tt may also invade the tubers at the stem end causing the flesh 
to blacken, and in bad cases leads to dry rot in winter storage, 
especially of the stem end of the tuber. It may be detected in the 
field by the wilting of the plants and in the tubers by cutting 
off a thin slice across the stem end, where the disease shows as a 
brownish black spot or ring where the vessels from the stem enter 
the flesh. This disease, as it occurs in the tuber, is likely to be 
confused with the other types of internal browning. The dis- 
tinctive characters are that this disease causes the tops to wilt 
and die and that the internal l^nckening of the tuber increases 
during storage and may lead to dry rot." 
ECONOMIC IMPORTANCE. 
Potato growing has long been a prominent part of the agri- 
culture of northwestern . Nebraska. The early "homesteaders" 
introduced potato culture into this region on a small scale to 
supply local needs. With the coming of the railroads the in- 
dustry made rapid strides and the Sand Hill and High Plains 
regions soon established an enviable reputation for the excellent 
quality of their potatoes. 
The full significance of the potato crop in this region may be 
seen from the following statistics taken from the last Tinted 
States Census Report covering tho crop year 1909. 
