Lack of activity of selected isoflavonoid phytoalexins as protectant fungicides

Abstract Seven isoflavonoid phytoalexins were subjected to a series of screening tests used for the routine examination of potential fungicides. The phytoalexins had no appreciable effects on disease intensity in these assays, which encompassed five major crop plants and six pathogens. It seems unlikely that isoflavonoid phytoalexins could be used as conventional fungicides in control programmes against phytopathogens.