Decapitation improves the efficiency of Cd phytoextraction by Celosia argentea Linn.

The effect of decapitation on enhancing plant growth and Cd accumulation in Celosia argentea Linn. was evaluated using a pot experiment. Decapitation significantly enhanced the growth of C. argentea. The numbers of branch and leaf in the decapitated plants (DP) were significantly higher than those in undecapitated plants (UDP, p < 0.05). Decapitation increased the biomass by 75%-105% for roots, 108%-152% for stems, and 80%-107% for leaves. Although the transpiration and photosynthesis rates were not significantly different between DP and UPD, decapitation significantly increased the total leaf area and total transpiration per plant (p < 0.05). The higher total transpiration per plant resulted in a higher leaf Cd concentration in DP. DP accumulated Cd in shoots (197, 275, and 425 μg plant(-1)) that were 2.5-2.8 times higher than UDP (78, 108, and 152 μg plant(-1)), with the soils containing 1, 5, and 10 mg kg(-1) Cd. Results suggested that decapitation is a novel and convenient method to improve the phytoextraction efficiency of C. argentea in Cd contaminated soils.