Description: By amination of polyvinil alcohol with N, N-dimethyl-4-amine-benzaldehyde and quaternization of the amine polymer obtained with dimethylsulphate, the bioactive aminepolymeric salt GN was obtained. In the period 2006-2007 GN in concentration 3 g/kg and 2 g/kg) as well as the alkyl ammonium salt Horti Desin (2 g/kg), were tested in two years experiment in field conditions against Alternaria porri f. sp. solani, the casual agent of early blight disease on tomatoes