In the thesis, we studied how hemp responds to extremely high concentrations of cadmium, lead and zinc in the soil and the effects of each given element on the growth and development of the plant. In a pot experiment, we tested the uptake of heavy metals: cadmium (Cd), lead (Pb), and zinc (Zn) into various parts of two hemp varieties ‘Tisza’ and ‘Futura 75’. For each element, two levels of soil contamination were prepared by adding heavy metals in chloride forms to non-contaminated soil: Pb-1/2 (1000 mg/kg), Pb-2/2 (1500 mg/kg), Cd-1/2 (50 mg/kg), Cd-2/2 (100 mg/kg), Zn-1/2 (2500 mg/kg) in Zn-2/2 (5000 mg/kg). The plants were grown in 3,5 L pots, one plant per pot, 10 plants of each variety in each combination, 70 plants together with control soil. The experiment was carried out in a greenhouse between January and July 2018. The results were harvested in July 2018 when the seeds were ripe. To determine the presence of heavy metals in various parts of the plant, we sampled: roots (primary and lateral individually), the stem (fibres and hurds individually), and inflorescences. Both of the varieties showed the highest content of Cd, Pb, and Zn in the fibrous roots, while phytotoxic effects (the plants decayed) were observed only in combinations where ZnCl2 was added and it was a concesuence of a high salt concentration. All parts of hemp grown in the soil contaminated with heavy metals contain heavy metals, therefore their use is limited.
|
