The first study included three fields experiments with green pepper, eggplants and sudax, irrigated with borehole water or with secondary treated municipal wastewater. Both waters were supplemented with N applied continuously with the irrigation water at four levels 0 g/m3, 50 g/m3, 100 g/m3 and 150 g/m3. Yield results indicate the superiority of the treated wastewater and its ability to produce high yields with less fertilizers. The second study included treated wastewater of a) Gerbera jasmesonii and b) for hydroponic culture of Limonium perezii and Antirrhinum. Gerbera jasmesonii was irrigated with secondary treated wastewater, borehole water and fresh water with or without additional fertilization. Results on flower production per plant shown that freshwater produced significantly more flowers per plant than the other water qualities and fertilization had a significant effect on flower production for freshwater irrigated plants but no significant effect on wastewater irrigated plants. Results on Limonium perezii and Antirrhinum in hydroponics, show that both plants irrigated with secondary treated wastewater and treated wastewater from the epuvalisation system were less vigorous and produced significantly less flowers of lower quality than flowers produced from plants irrigated with freshwater with the addition of fertilizer.