VIEW ARTICLE

Effect of Soil Moisture and Temperature on Viability of Sclerotia of Sclerotium oryzae. R. Keim, Department of Plant Pathology, University of California, Davis 95616, Present address of senior author: Superintendent, University of California, South Coast Field Station, 7601 Irvine Blvd., Santa Ana 92705; R. K. Webster, Department of Plant Pathology, University of California, Davis 95616. Phytopathology 64:1499-1502. Accepted for publication 18 June 1974. DOI: 10.1094/Phyto-64-1499.

Alternate wetting and drying of sclerotia of Sclerotium oryzae resulted in substantial loss of sclerotial weight accompanied by reductions in viability. Viabilities of sclerotia recovered from wet soils after incubation at 24 C were significantly lower than the viabilities of those incubated at 1 C and those incubated at 24 C after they were recovered from soils that had been allowed to dry. They were also lower than viabilities of sclerotia subjected to alternate wetting and drying. It would appear that a soil fungistatic factor was imbibed by sclerotia and retained after their recovery from soil.