Effects of Rotations with Susceptible and Resistant Peanuts, Soybeans, and Corn on Inoculum Efficiency of Cylindrocladium crotalariae on Peanuts. M. C. Black, Former Research Assistant, Department of Plant Pathology, North Carolina State University, Raleigh 27650-5397. M. K. Beute, Professor, Department of Plant Pathology, North Carolina State University, Raleigh 27650-5397. Plant Dis. 68:401-405. Accepted for publication 28 November 1983. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-401.

Field microplots were infested with microsclerotia (ms) of Cylindrocladium crotalariae at about 35 ms/g soil. Susceptible Florigiant peanuts, resistant NC 3033 peanuts, soybeans (a host), and corn (a nonhost) were planted in all possible rotations in 1979 and 1980. Florigiant or NC 3033 were planted in microplots in 1981 after rotations established in 1979 and 1980. Postharvest inoculum densities in 1979 and 1980 for Florigiant and soybeans were similar and greater than for NC 3033 and corn. However, efficiency of ms to induce peanut root rot was high following NC 3033, intermediate following Florigiant, and low following soybeans. Variation in inoculum efficiency following different rotation crops was attributed to differences in ms genotype and phenotype, concentration of residual nitrogen in soil, and soil microflora.

Keyword(s): Arachis hypogaea, Glycine max, Zea mays.