No abstract

The morphological and physiological response of papaya plants exposed to cadmium (Cd) contaminated soil was evaluated using 2 and 10% organic matter (OM), low organic matter (LPOM) and high organic matter (HPOM) soil, respectively. Cadmium chloride (CdCl2) was added weekly at doses of 50, 100 and 150 mg/L and a control treatment. Height, stem thickness, number of leaves, chlorophyll, Cd accumulation in root, stem and leaf were evaluated and the translocation factor (TF) was determined. The results showed that growth inhibition was proportional to the increase in the concentration of added Cd. Plant height in LPOM soil was reduced by 13, 23 and 27% compared to the control group in HPOM soil. Chlorophyll content was reduced by 19, 23 and 36% in the LPOM soil relative to the HPOM treatment. TF results in all treatments were less than 1, indicating that the root did not allow Cd transport to the aerial part of the plant. It was also found that the presence of a higher OM concentration in the soil decreased the metal uptake by the plant; this suggests that the application of organic amendments is a technological alternative to reduce the risk of Cd uptake in agricultural crop soils.