Effect of Application of Treated Wastewater on Seed Yield and Heavy Metals Content of Safflower Cultivars

Treated wastewater could be a valuable source of water for recycling and reuse in arid regions. Two one-year field experiments were carried out to determine the effects of municipal treated wastewater on seed yield and seed heavy metals content of safflower cultivars, in Research Farm of Yazd Municipal Wastewater Purification Station, during 2015 and 2016. The experiments were arranged as split plot based on a randomized complete block design with three replicates. Irrigation treatments were in the main plot, consisting of three irrigation strategies (irrigation with only treated municipal wastewater, irrigation with treated wastewater/fresh water alternatively, and irrigation with only fresh water) and three safflower (Carthamus tinctorius) cultivars (Sofeh, Isfahan native, and Goldasht) in the subplots. Results showed that yield and yield components increased by treated wastewater treatment compared to the other irrigation treatments. Application of treated wastewater caused increase in safflower grain (40%) and biological (9%) yield as compared to fresh water treatment. Treated wastewater application led to accumulation of trace elements (Fe, Mn, Cu, Cd and Pb) in safflower seeds; however, the content of all the metals were below the permissible limits recommended by World Health Organization.