Heavy Metal Contamination in Peach Trees Irrigated with Water from a Heavily Polluted Creek

ABSTRACT

This study was conducted to characterize the heavy metal contamination in the soils of peach orchards irrigated with water from Nilüfer creek, which is heavily polluted by industrial and municipal wastes. Twenty-one peach orchards with 3 different cultivars in 7 orchards each located along Nilüfer creek were monitored in the experiment. To determine levels of pollution, soils and aboveground parts of the trees were sampled and analyzed for iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), cobalt (Co), nickel (Ni), chromium (Cr), lead (Pb), and cadmium (Cd). Total amounts of Ni and Cr were found to be at the excessive levels in soils. Extractable Ni concentration decreased with increasing pH and CaCO₃ content in soils. Leaf metal contents were generally at tolerable levels, but Ni and Pb accumulated to toxic levels in different parts of the fruit (flesh and peel). Except for Fe and Ni, plant concentrations of the metals did not correlate with their total and DTPA-extractable concentrations in the soils. There was no significant difference among the cultivars in accumulation of heavy metals.

Keywords:

• heavy metal
• irrigation
• peach
• soil
• pollution

ACKNOWLEDGMENTS

The research was funded by TÜBİTAK/TOGTAG (The Scientific and Technical Research Council of Turkey/Research Grant Committee for Agriculture, Forestry and Food Technologies) competitive grant no: Tarp–2397 awarded to Haluk Başar as principal investigator. The authors would like to thank Dr. G.H. Neilsen from Pacific Agriculture and Agri-Food Canada for useful comments on the manuscript.

Notes

**: significant at the 1 % level.

*: significant at the 5 % level.