Sunflower (Helianthus annuus) and castor (Ricinus communis)
seeds were annually collected on a 3-year period (2007, 2008,
2009) from a slow rate (SR) pilot cultivation for urban wastewater
treatment in Heraklion wastewater treatment plant in Crete,
Greece. The SR system that was constructed for the needs of the
experiment was of Type 2, i.e. just enough water was applied to
satisfy the total irrigation requirements of the crops that were
grown in order to optimize the water reuse potential