Absorption and Translocation Capacity of Cadmium in Papaya (Carica papaya L.) Plants With Addition of Organic Matter

Abstract

Cadmium (Cd) is a toxic element that can be easily absorbed by crops, and can enter through the frequent use of fertilizers in crop areas. The objective of this study was to evaluate the bioaccumulation percentage (BAP) and translocation factor (TF) of Cd in papaya plants exposed to contaminated soils at 50, 100 and 150 mg L-1 and at two concentrations of organic matter: 2% and 10%-MO. Growth variables, chlorophyll and metal concentration were measured after 10 months of cultivation. The results indicated that the greatest growth occurred in soil at 10%-OM in relation to those grown at 2%-OM. Cd bioaccumulation was leaves < stem < root (9 < 22 < 68%) at 50 mg L-1, (7 < 29 < 65%) at 100 mg L-1 and (4 < 34 < 63%) at 150 mg L-1, observing the greatest accumulation in the root. The findings showed that organic matter in soil decreases the availability of metal uptake in the roots. The translocation results were < 1, indicating that the root has the ability to restrict metal transport to the aerial part in plants grown in 10%-OM soil, however, in 2%-OM soil it tends to increase this metal accumulation, suggesting that the application of organic amendments is an alternative to reduce the risk of Cd absorption in agricultural soils.