Schiff Bases as Potential Fungicides and Nitrification Inhibitors

A number of substituted Schiff bases were synthesized and characterized by H-1 NMR and mass spectrometry. These compounds were screened for antifungal activity in vitro against pathogenic fungi, namely, Sclerotium rolfsii and Rhizoctonia bataticola, and for their effect on nitrification inhibition under laboratory conditions. Maximum antifungal activity was exhibited by (2,4-dichloroben ylidene)-(2,4,5-trichlorophenyl)-amine and (3-nitrobenzylidene)-(2,4,5-trichlorophenyl)-amine against both fungi (ED50 with range from 3 to 24 mu g/mL). Maximum nitrification inhibition (NI) was exhibited by (2,4-dichlorobenzylidene)-(2-fluorophenyl)-amine,(4-fluorophenyl)-(3-nitrobenzylidene)amine, (2,6-dichlorobenzylidene)-(4-fluorophenyl)-amine, and (2,6-dichlorobenzylidene)-(3 fluorophenyl)amine (NI in the range 91-96%).