The disease has increased in importance as no-till and continuous corn cropping management systems have intensified. Epiphytotics are favored by cool, wet weather. May be confused with genetically based leaf spots. The upper leaves may wither and die prematurely. The pathogen survives in re sidues at or near the soil line.
Resistant lines have been developed is also available.
Fungicides incorporating benomyl or propoconazole have been shown to be effective. The disease was first described in the United States in 1925. It is now widespread and ranges from Iowa to Atlantic coast. It thrives under hot, humid conditions. In the past, attacks tended to be somewhat localized, but epiphytotics have now become regional in scope.