TALINUM PANICULATUM CULTIVADO EM LATOSSOLO VERMELHO CONTAMINADO COM CHUMBO

Abstract

This work aimed to evaluate the growth and production of dry mass of Talinum paniculatum cultivated in a Red Latosol contaminated by lead. The plants were submitted to Pb concentrations of 0, 100, 200, 600 and 1200 mg dm-3 of soil, with five replicates per treatment. The experiment was conducted under a completely randomized design, in a greenhouse. The diameter, height and number of leaves were evaluated weekly. After 90 days, the dry mass of leaves, stems and roots were analyzed, in addition to quantifying the levels of total and available lead (DTPA) in the soil. There were no significant differences between treatments for any of the parameters analyzed, despite evidence from the literature regarding the deleterious effects of high concentrations of lead on plant growth. Due to the clayey texture and high organic matter content, almost all of the applied lead remained retained in the soil, unavailable to plants, which was attested by the low concentrations of available Pb found at the end of the experiment (maximum 6.8 mg kg -1). The low levels available are consistent with the evidence in the literature regarding the high adsorption capacity of Pb by Oxisols. Thus, despite the fact that lead is a toxic element to plants, its immobilization in the soil restricted the manifestation of toxic effects on the plant.