Mar, 19, 1917 
Peanut-Wilt Caused by Sclerotium Rolfsii 
447 
Thompson and Bailey 1 classify Valencia and Tennessee Red peanuts 
as the same variety, but the writer noted sufficient difference in resist¬ 
ance to 5 . Rolfsii to make it advisable to consider these two as separate 
varieties from a pathological viewpoint. 
As the Virginia Runner, Virginia Bunch, and Spanish varieties are the 
three varieties grown in Virginia, there is little to be feared from the 
attacks of S. Rolfsii in commercial fields in this State. If, however, 
this organism should get established in a soil used for peanuts, it would 
seem advisable to grow resistant varieties in preference to carrying on 
a rotation of more than three years in order to starve it out. 
EFFECT OF SCLEROTIUM ROLFSII ON CRIMSON CLOVER USED AS A 
COVER CROP 
Wolf 2 mentions cowpeas and crimson clover as succumbing to artificial 
inoculations with S. Rolfsii . The crimson clover grown for a winter 
cover crop on the experimental peanut plots at Norfolk is generally 
planted in September or October and turned under in May. Under these 
field conditions in Virginia the writer has observed no infection of crimson 
clover during 1915 and 1916. 
SUMMARY 
(1) Ini9i5a wilt of peanut plants was found in experimental plots at 
the Virginia Truck Experiment Station. 
(2) The causal organism was probably introduced into the plots in 1913 
with a fresh supply of Valencia seed imported that year. 
(3) The disease under field conditions appeared when the plants were 
from 1 to 2 months old and continued to develop throughout the season. 
(4) The wilting was due to the fungus attacking the shoots at or near 
the surface of the soil and killing the invaded tissues. White mycelium 
and brownish sclerotia about the size of mustard seed were found about 
the base of wilted peanut stems and also on peanut leaves which had 
dropped to the soil about the base of wilted plants. Mycelium and 
sclerotia were also found associated both externally and internally on 
the pods on diseased plants. 
(5) Wilted plants were scattered over the entire area of each plot, thus 
indicating that the causal organism was well distributed. In some cases 
several adjoining hills were observed to wilt in a progressive way, which 
indicated the spreading of the fungus from one hill to the one adjoining 
in the same row. 
(6) Isolations from diseased shoots and inoculations with pure cul¬ 
tures of the associated organisms established the pathogenicity of the 
fungus producing the coarse white mycelium and brownish sclerotia. 
Comparisons of pure cultures of this fungus with descriptions and stock 
1 Thompson, H. C., and Bailey, H. S. Peanut oil. U. S. Dept. Agr. Farmers’ Bui. 751 , 16 p. 1916. 
2 Wolf, F. A. Op. cit., p. 144 - 145 - 
