Abstract: The present invention relates to the use of polymeric guanidine derivatives for the curative and/or preventive treatment of unwanted microorganisms such as bacteria and phytopathogenic fungi in crop protection including the treatment of seed. The invention furthermore relates to novel active compound combinations comprising at least one polymeric guanidine derivative and at least one further fungicidally active compound, their use for the curative or preventive treatment of unwanted microorganisms in crop protection including the treatment of seed and not least the treated seed itself.

Abstract: The invention relates to the use of polymeric guanidinium hydroxides based on a diamine which contains oxyalkylene chains and/or alkylene groups between two amino groups, obtainable by polycondensation of a guanidine acid addition salt with the diamine, whereby a polycondensation product in the form of a salt is obtained, which subsequently is converted into the hydroxide form via basic anion exchange, for controlling microorganisms.