Friesia X, 4-5

- 305
Fig. 3. Cenococcwm. geophilum. Sclerotia found in field No. 35 (ca. 15 X).
INGE PRÆST phot.
During this examination it was discovered that the soil samples
contained sclerotia of Cen ococcu m geophilum.
Twenty soil samples already analysed for seed content were
checked for content of sclerotia (cf. Fig. 1, Nos. 1-19 and 33), but
owing to the treatment given these samples during analysis for
seed, it was impossible to determine the exact number of sclerotia
per m''.
The remaining 37 soil samples, at that time not analysed for
content of seed, were examined at a magnification of 20-40 X in
order to sort out the sclerotia or sclerotia-like particles (cf. Fig. 1,
Nos. 20-32 and 34-57). Most of these soil samples contained a very
high amount of sclerotia, and the analysis work was therefore very
time-consuming, which made it necessary to divide the washed fraction.
The coarse part ( > 1 mm) contained relatively few sclerotia,
and half of this fraction was examined. af the fine fraction « 1 mm)
- which often had a very high content of sclerotia - usually 1/16
was analysed. an an average 2828 sclerotia per reduced sample
and also some sclerotia-like particles were found in the 37 samples
examined.
At the identification of the sclerotia were used samples of Ceno-
F R IESIA X 20