Investigations into the cytokinin-like properties of benzimidazole -derived fungicides

Of seven systemic benzimidazole fungicides tested, four showed cytokinin activity in a modified Amaranthus betacyanin bioassay. In the presence of the gibberellins A₄ and A₇, in the dark at 25°C, the four active compounds stimulated the germination of seeds of two celery cultivars dependent on cytokinin for germination under these conditions. One cytokinin-active fungicide was methyl benzimidazol-2-yl carbamate (MBC) and the other three break down into this compound in solution. The three inactive fungicides do not. However, the hormonal properties of the cytokinin-active fungicides may not be due to the MBC moiety alone because sometimes they were more cytokinin-active than pure MBC.