Barley root concentration factor

Root uptake has been proven to be an important pathway for contaminants with intermediate octanol-water partitioning coefficients (Aiow)- Variable uptake of an organic compound by different plants has been observed. Plant species such as Daucus carota (carrot) and Pastinaca sativa (parsnip) with swollen storage roots did not translocate chemicals as well as expected from barley experiments. While the lipid content was considered a factor, plant structure, root types, and other properties may all play a role. The effect of the chemical itself was best illustrated by the increasing root concentration factor (RCF) and the bell-shaped transpiration stream concentration factors (TSCF) relative to logAiow- The physiochemical properties of compounds, including the Ko, solubility, and... 

TABLE 5.4 Root Concentration Factors and Transpiration Stream Concentration Factors for Phenyl Ureas in Barley Seedlings... 

Figure 5.7 Root concentration factor (log RCF) expressed as a function of log Ko. O, 0-methylcarbamoyloximes x, substituted pbenylureas. [Reproduced from G. G. Briggs, R. H. Bromilow, and A. A. Evans, Relationships between lipophilicity and root uptake and translocation of non-ionised chemicals by barley Pestic. Sci, 13, 495. Copyright 1982, Society of Chemical Industry. Reproduced with permission granted by John Wiley and Sons, Ltd on behalf of the S.C.I.]...

Figure 9.4. Relationship between the uptake of chemicals by plant roots (expressed as their root concentration factor) and their octan-l-ol/water partition coefficients (as log (a) in barley roots O, 0-methylcarbamoyloximes x, substituted phenylureas (b) literature values for several herbicides and fungicides in different plant species. (Reproduced from Ref. 34.)...

Topp et al. (1986) conducted similar uptake experiments with barley plants grown from seed for 7 days in soil containing individual " C-labeled organic chemicals at concentrations of 2 mg/kg. Root concentration factors (CFsoil), defined similarly as the concentration of chemical in the root (fresh weight) divided by the concentration of the chemical in the soil pore water, were determined and found to be correlated with log Kovf as shown ... 

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