CLOVER STEM ROT 1 
By 
FREDERICK A. WOLF AND R. O. CROMWELL 
INTRODUCTION 2 
There lias been present for several years in North Carolina a stem 
rot disease of crimson clover, Trifolium incarnatum. This disease has 
attracted attention because it results in the death of all plants in well- 
defined areas, involving in some instances, spots of considerable extent. 
Numerous inquiries as to the cause of this condition have been received 
during the past few years at the North Carolina Experiment Station 
and have led to an investigation of the nature of this stem rot disease. 
Furthermore, the growing importance of crimson clover as a cover crop 
and as an invaluable means of increasing and maintaining soil fertility 
makes it desirable to circulate the facts established by this investiga¬ 
tion as widely as possible. It seems advisable, therefore, to present at 
this time, data bearing upon the history and distribution of the disease, 
on the relationship and life history of the causal organism, and on 
methods for the prevention and control of its ravages. 
Historical 
The disease in epidemic form has long been known in Europe and 
was observed as early as 1857 (14, 15, and 18) near Beberbeck, in the 
province of Hesse, Germany. Here it appeared in a field seeded with a 
mixture of red clover, Trifolium pratense and white clover, Trifolium 
repens, and was noted to be more destructive during the moist winter 
weather than during the preceding dry autumn. In 1870 it was first 
noted in Denmark and by 1878 it had spread to Sweden. 
Two extensive accounts of this disease in Europe have appeared, one 
by Rehm (18) in 1872 and the other by Eriksson (6) in 1880. The 
first of these deals primarily with the morphology and development of 
the causal organism which is identified as Peziza ciborioides Er. It also 
contains suggestions for the control of the disease and a record of 
observations upon the host species which were found to include red 
clover, white clover, crimson clover, and alsike clover, Trifolium 
hybridum. Among the other leguminous plants which were exposed to 
infection, but which remained healthy were alfalfa, Medicago sativa, 
sainfoin, Medicago falcata, black medic, Medicago lupulina, Onobrychis 
sativa, Ornithopus sativa, white sweet clover, Melilotus alba, and blue 
sweet clover, Melilotus caerulea. The other account deals with the dis¬ 
tribution of stem rot and with the life history and nomenclature of the 
1 Submitted for publication December 10, 1917. 
2 The junior author is now at the Iowa Agricultural Experiment Station, Ames, Iowa. 
