Förster, Helga Spiral gradient dilution, a rapid method for determining growth responses and 50% effective concentration values in fungus-fungicide interactions. [electronic resource] - Phytopathology Feb 2004 - 163-70 p. digital Publication Type: Journal Article ISSN: 0031-949X Standard No.: 10.1094/PHYTO.2004.94.2.163 doi