Soil Components That Affect Severity of Cylindrocladium Black Rot on Peanuts. M. C. Black, Former Research Assistant, Department of Plant Pathology, North Carolina State University, Raleigh, NC 27650. M. K. Beute, Professor, Department of Plant Pathology, North Carolina State University, Raleigh, NC 27650. Plant Dis. 69:36-39. Accepted for publication 12 June 1984. Copyright 1985 The American Phytopathological Society. DOI: 10.1094/PD-69-36.

Increases in densities of actinomycetes and bacteria and increases in copper levels in soil from peanut, soybean, and corn fields were associated with decreases in root rot severity on peanut seedlings after infestation with microsclerotia of Cylindrocladium crotalariae. Root rot was more severe after infestation of untreated soil from corn fields than from soybean fields. Peanuts grew better after adding actinomycetes cultured from soils at one location than with actinomycetes from soils at a second location, but root rot severity was not affected by actinomycetes from two locations. Actinomycete density in C. crotalariae-infested soil in microplots was greater with soybeans than with peanuts or corn. Severity of Cylindrocladium root rot was not affected when actinomycetes from microplots were used to amend soil, but the actinomycete populations from peanut and soybean microplot soils enhanced plant growth compared with those from corn microplot soils.

Keyword(s): Arachis hypogaea, suppressive soil.