This study is an experiment designed with five watering regimes as follows: raw wastewater (T1), treated wastewater (T2), a combination of 50% raw wastewater and 50% fresh water (T3), a combination of 50% treated wastewater and 50% fresh water (T4), and fresh water (T5). The results show that the average Mn, Fe, Cu and Zn values in the drained water were less than the input water. The effect of watering on heavy metal concentration of the drainage water was statistically significant. Temporal analysis showed increasing trends for the heavy metals from T1 to T5. In the case of T1, after the third irrigation programme, Zn, Mn and Fe concentrations were reduced. Based on Pearson’s correlation coefficients, Mn, Fe, Cu and Zn in drainage waters had significant positive correlation with each other. Also, the treatments had significant effects on heavy metal concentrations in potato shoots and tubers (except Zn in tubers). Based on heavy metal accumulation in drainage waters, potato shoots and tubers, the treated watering order was T1>T3>T2>T4>T5 (except Fe in shoots). The heavymetal concentration in tubers was less than in shoots. Cu and Zn accumulation in potato was within standard limits. Copyright © 2014 John Wiley & Sons, Ltd.
