being similar to each other between the Padaeng area and agricul- tural field (Table 1).
The decrease in Cd observed for some of the plants between 37 and 57 d is due to plant growth, since the mass of all plants more than doubled between the two harvest times (Table 1). Despite these concentration decreases, the total Cd amounts in all plants, except for C. odorata, increased between 37 and 57 d (Table 1). The Cd amounts in G. pseudochina, C. sumatrensis, and N. tabacum more than doubled between 37 and 57 d (Table 1). Hence, if the phytoremediation method was employed again in the soil of Mae Sot using one of these plants, and with similar environmental con- ditions to those of our field study at the time of the experiments, the remediation period should be longer than 37 d. N. tabacum transferred during 57 d from the soil to its tissues the highest amounts of Cd, which were five times higher than those accumu- lated in the same plant species growing for 90 d in pots where Cd had an initial soil concentration of 3 mg kg