Biological Activity and Dissipation of IPC and CIPC

Conflicting reports on the dissipation of ie isopropylN-phenylcarbamate (IPC) and isopropylN-(3-chlorophenyl) carbamate (CIPC) prompted the present investigation on the dissipation and biological activity of these two herbicides. The dissipation patterns of IPC and CIPC were similar. Under the field and laboratory conditions described, more than 90% of both herbicides was gone in 4 weeks. CIPC was biologically more active than IPC on all plants tested, and both herbicides were nearly 10 times more toxic to buckwheat (Fagopyrum esculentumMoench.) in quartz sand as in a silt loam soil. Although both herbicides were present in equal amounts throughout their dissipation, CIPC appears to persist longer in field applications, as it is more toxic to most plants than IPC.