Fig. 5. Growth stage: maturity. Activities of ⁵⁴Mn, ⁶⁵Zn, ⁵⁷Co, and ¹³⁴Cs measured in the unstained soil matrix, in the stained preferential flow paths, and in the 2-cm fringe just outside the stained flow paths. Samples were taken at harvest time when plants reached maturity. Means and standard errors are given. The symbols *, **, and *** indicate significance at the 0.05, 0.01, and 0.001 probability levels, respectively; while NS is not significant at the 0.05 probability level and ND is not detectable.