Colletotrichum coccodes: A Pathogen of Eastern Black Nightshade (Solanum ptycanthum)

The fungusColletotrichum coccodes(Wallr.) Hughes was isolated from diseased plants of eastern black nightshade (Solanum ptycanthumDun. ♯ SOLPT) growing in the field. In greenhouse experiments, the isolate was highly pathogenic to eastern black nightshade and less so to seven other weedy species within the Solanaceae. No disease symptoms were observed on seedlings of tomato (Lycopersicon esculentumMill.), potato (Solanum tuberosumL.), or 10 other species inoculated with the isolate. Dew periods of 16 h or longer were required for maximum disease development. This requirement could limit the practical use of this pathogen as a my coherbicide.