Effects of Inoculum Burial, Temperature, and Soil Moisture on Survival of Cylindrocladium crotalariae Microsclerotia in North Carolina. J. K. Pataky, Graduate Research Assistant, Department of Plant Pathology, North Carolina State University, Raleigh 27650. M. K. Beute, Professor, Department of Plant Pathology, North Carolina State University, Raleigh 27650. Plant Dis. 67:1379-1382. Accepted for publication 4 July 1983. Copyright 1983 American Phytopathological Society. DOI: 10.1094/PD-67-1379.

Survival of Cylindrocladium crotalariae microsclerotia on the soil surface during the winter was reduced compared with that of microsclerotia buried 25 cm below the soil surface. Less than 5% of the initial number of microsclerotia placed on the soil surface in November were recovered after 12 wk. Percentage recovery of initial inoculum from samples buried at 25 cm for 24 wk was 31, 2.2, and 55% for microsclerotia on stems in 1981, microsclerotia on stems in 1982, and microsclerotia in soil in 1982, respectively. Moisture content and weight of buried samples were less variable than for samples placed on the soil surface. Viability of microsclerotia at 4 C was greater in very moist soil than in dry soil. Temperature and moisture appeared to interact in their effect on microsclerotial viability, which may partially explain the increased ability of microsclerotia to survive when buried.

Keyword(s): Arachis hypogaea, Cylindrocladium black rot (CBR).