Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Characterization of Pythium spp. from three Ohio fields for pathogenicity on corn and soybean and metalaxyl sensitivity.

Abstract

Pythium spp. were baited with maize and soyabean seeds from soils collected from 3 locations (Defiance, Sandusky and Wood) in Ohio, USA where soyabean and maize 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 maize and soyabean 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 3 locations. It is suggested that repeated use of metalaxyl as a seed treatment to manage Pythium spp. may be selecting for insensitive strains of these species.