Passive Absorption — Additional Accumulation Mechanisms
In addition to ion trapping, herbicides may accumulate in plants cells to concentrations greater than equilibrium concentrations by other mechanisms. These mechanisms include conversion to non-phytotoxic metabolites, binding to cellular constituents, or partitioning into lipids. In contrast to ion trapping, herbicides accumulated by these mechanisms are probably not available for herbicidal activity, particularly when structural changes have occurred, as in the case of herbicide metabolism. These are mechanisms by which a plant renders the herbicide ineffective.