EDTA effects on seedling emergence and growth of Chenopodium album (L.) in Pb contaminated soil

The study was conducted to investigate the effects of ethylenediaminetetraacetic acid (EDTA) on seedling emergence, morphological characteristics, and photosynthetic pigments of Chenopodium album (L.) in lead (Pb) contaminated soil. The Pb contaminated soils were taken from Hirmand River. The soil samples mixed with 0.71 g Li-1 Pb (PbNO3)2 to increase the Pb concentration. EDTA was added to the soil in concentrations of 1.5, 3 and, 9 mg kg-1 after sowing the seeds. Results showed that EDTA significantly decreased seedling emergence. The highest reduction in germination was related to 9 mg kg-1 EDTA. With increasing EDTA dosage, mean seedling emergence time increased. The highest seedling vigor index (17.29) was related to the control treatment while the lowest seedling vigor index (2.15) was measured in 9 mg kg-1 EDTA. With increasing EDTA concentration, plant biomass decreased. The highest reduction was observed in 9 mg kg-1 EDTA. The maximum and minimum pedicel length, radical length, and tolerance index were measured in 1.5 and 9 mg kg-1 EDTA treatments, respectively. The highest amounts of chlorophyll a, b, total chlorophyll, and carotenoid were observed in 1.5 mg kg-1 EDTA. Increased EDTA from 1.5 to 9 mg kg-1 led to a decrease in photosynthetic pigments.In general, results showed that EDTA at high concentrations had deterrent impacts on the plant growth. Therefore, high concentrations of this compound are not suggested to increase remediation efficiency of Pb contaminated soil.