Fig. 7. Growth stage: maturity. Relation between brilliant blue FCF and the concentration of radionuclides in the three soil compartments analyzed: preferential flow paths; 2-cm fringe just outside the stained flow path areas; soil matrix; each point represents the average of the soil samples taken on horizontal profiles at 15-, 18-, 20-, 35-, 38-, and 40-cm depth. Samples were taken at harvest time when plant reached maturity. r denotes the Pearson product-moment correlation coefficient.