Phytotoxicity Increase Induced by Zinc Accumulation in Cichorium intybus

The accumulation of zinc (Zn) in Cichorium intybus and effects of phytotoxicity during 90 days of growth on (natural) non-contaminated and Zn-contaminated soils were studied. The phytotoxicity effects were monitored by evaluating the leaf area, leaf biomass, leaf length and root length of the vegetable. The Zn concentrations ranged from 5.35 ± 1.05 to 37.5 ± 3.89 mg kg^-1 in leaves of plants grown on natural soil, and from 334.0 ± 25.6 to 2232 ± 16.7 mg kg^-1 when grown on Zn-contaminated soils. Zn accumulation caused a decrease in growth on contaminated soils and an increase in phytotoxicity. These effects were associated to high metal concentration, mobility and bioavailability in the soil as well as changes in the translocation mechanism from the roots to the leaves. Then, it must be avoided the organic fertilization of soils with either animal manure or other agricultural inputs containing high zinc concentrations.