Table 1.

Treatments applied on poplar plants after reaching their 4-leaf stage

	1st week			2nd and 3rd week
Treatment (1·w/2–3·w)	10 µm Fe	50 µm Fe	10 µm Cd	10 µm Fe	50 µm Fe	10 µm Cd
Ctrl/Ctrl	×			×
Ctrl/Ctrl-50	×				×
Cad/Cad	×		×	×		×
Cad/Ctrl	×		×	×
Cad/Ctrl-50	×		×		×
Cad/Cad-50	×		×		×	×
Cad-50/Cad-50		×	×		×	×

Plants were treated with/without 10 µm Cd(NO₃)₂ for 1 week, and then allowed to recover or be treated under different circumstances. Ctrl (control) = 10 µm Fe-citrate; Cad = 10 µm Cd, 10 µm Fe-citrate; Ctrl-50 = 50 µm Fe-citrate; Cad-50 = 10 µm Cd, 50 µm Fe-citrate.