In a field experiment, the survival and the viability of Sclerotium rolfsii sclerotia on the soil were quantified. Fifty-two sclerotia multiplied on PDA culture medium were placed in fabric bags. In a wooden frame containing soil, 18 replicates were placed on the surface and buried at 10 cm depth, respectively. The bags were monthly removed from each position, washed under running water and compressed with the finger to verify whether they kept intact or not. Intact sclerotia underwent sterilization with 70% alcohol and 1% sodium hypochlorite for one minute; then, they were deposited on plates containing PDA culture medium and stored in a growth chamber at 25 ºC in the absence of light. Three days after incubation, germinated sclerotia were counted. Sclerotia collected from the surface lost their viability after eight months, while buried ones kept viable until the fifteenth month. S. rolfsii sclerotia on the surface tend to lose their viability in a shorter period than buried ones.
Resting structure; longevity; viability
