292 
Journal of Agricultural Research 
Vol. V, No. 7 
roots were also made with a culture of Sclerotinia libertiana obtained 
from lettuce from South Carolina. The procedure followed in the inocu¬ 
lations was as follows: Healthy ginseng plants with the tops still attached 
were selected and the soil carefully removed from one side of the root. 
By means of a flamed scalpel longitudinal cuts were made in the side of 
the root. These cuts were approximately one-fourth of an inch in length 
and about one-eighth in depth. A piece of agar containing mycelium 
from young cultures was inserted within these cuts and covered with soil. 
Check roots were treated in a similar manner. 
During the summer inoculations were made as shown in Table I. The 
checks in every case remained healthy. 
Table I .—Results of the inoculation of ginseng with Sclerotinia libertiana from various 
sources 
Number 
Date. 
Source of culture. 
of 
roots 
inocu¬ 
lated. 
Number 
of checks. 
Percent¬ 
age of 
infection. 
July 14 
Sclerotinia libertiana from South Carolina from 
lettuce. 
6 
2 
IOO 
15 
Sclerotinia sp. from Mentor, Ohio, from ginseng. 
6 
2 
IOO 
i 5 
Sclerotinia sp. from Newtown, Pa., from ginseng. 
Sclerotinia sp. from Edenville, Mich., from 
8 
4 
IOO 
83+ 
IOO 
erinsens? .. 
6 
2 
Aug. 1 
Sclerotinia sp. from Mentor, Ohio, from ginseng. 
4 
1 
1 
Sclerotinia libertiana from South Carolina from 
lettuce... 
4 
1 
75 
Plate XXVIII, figures 1 and 2, is reproduced from photographs of 
ginseng roots from two of the above series. Figure 1 shows a root 
inoculated with Sclerotinia libertiana isolated from lettuce. Figure 2 
shows three roots (on the left) inoculated with a species of Sclerotinia 
isolated from ginseng. 
Reisolations were made from the inoculations of July 15 and the 
fungus was again grown in pure culture. Inoculations made with the 
reisolated culture gave positive results. 
Infection was evident in from three to seven days after inoculation. 
The root at the point of inoculation becomes soft and the rot spreads 
gradually in all directions, causing the entire root to beame soft and 
doughy. After the mycelium has penetrated throughout the tissues of 
the root, it forms tufts of cottony-white felt, in which large black scle- 
rotia rapidly develop. Sclerotia on the outside of the root have in some 
cases developed within 10 days after the inoculations were made. When 
the inoculations are made near the crown of the root, the mycelium 
spreads to the stem, where it develops similar sclerotia on both the 
inside and the outside of the stem. The rapidity with which the disease 
progresses in the inoculted roots depends upon moisture conditions. 
