Oct. 1, 1925 
Sclerotinia Species Causing Decay of Vegetables 
623 
involving 14 strains of S. libertiana , 4 of S. minor, and 1 of S. inter¬ 
media. The cultures were 
made on potato-dextrose 
agar. 'The inoculum in each 
instance was a small bit of 
agar containing a young, vig¬ 
orously growing mycelium. 
All cultures were held at 15° 
C. for 12 hours, in order to 
let the fungi establish them¬ 
selves, and were then placed 
in cold storage at 0°. The 
temperature was carefully 
checked throughout the ex¬ 
periment, and the range was 
found to be —0.5 to 0°, as 
shown by Figure 2. 
During the 12-hour period 
in which the cultures were all 
at 15° C., S. minor and S . 
intermedia made a radial 
growth of 0.5 mm., while S. 
libertiana grew 1 mm. It will 
be noted that immediately 
following storage at 0° the 
rate of growth of S. libertiana 
was considerably checked. 
5. minor continued at a 
slightly faster rate than S. 
libertiana, while S . intermedia 
made rapid growth in com¬ 
parison. At the end of the 
10-day period, S . intermedia 
had made slightly more than 
twice as great a radial growth 
as either of the other species 
This ratio of growth was 
maintained up to tempera¬ 
tures slightly above 0 °. 
Thereafter these differences 
become gradually less marked 
until at 7° each of these 
species makes approximately 
the same rate of growth (pi. 
6, C). At all temperatures 
above 7°, S. libertiana grad¬ 
ually makes more rapid head¬ 
way until when a tempera¬ 
ture of 20° is obtained, it 
grows about twice as fast as 
either of the other species 
(pi. 6, A, B, and D). 
