Characterization of Pythium spp. from Three Ohio Fields for Pathogenicity on Corn and Soybean and Metalaxyl Sensitivity

Pythium spp. were baited with corn and soybean seed from soils collected from three locations in Ohio where soybean and corn stand establishment was a concern. Five species, P. catenulatum, P. irregulare, P. paroecandrum, P. splendens, and P. torulosum, were recovered and a subset of these isolates was then tested for pathogenicity on corn and soybean seed and sensitivity to the seed treatment fungicide metalaxyl. There was a range of both pathogenicity and sensitivity to metalaxyl within and among the Pythium spp. recovered from the three locations. A more thorough evaluation of the Pythium populations that exist in grain production fields in the north central region of the US is needed to facilitate the development and deployment of broader based seed treatment products. Accepted for publication 12 January 2004. Published 2 February 2004.