Lack of toxicity of Helminthosporium maydis-invaded corn and culture filtrates to chicks and mice.

Six isolates of Helminthosporium maydis, obtained from southern leaf blight-damaged corn, were grown separately on autoclaved corn and fed to chicks and mice to evaluate their toxigenicity. Two-, three-, and four-week-old culture filtrates from three pathogenic isolates grown separately on modified Fries medium were also evaluated for toxigenicity. None of the invaded corn samples or culture filtrates affected the weights of chicks or mice when compared to controls. Postmortem examinations did not reveal significant gross lesions. H. maydis was not toxigenic under our experimental conditions.