Salinity effects on germination and yield of purslane (Portulaca oleracea L.) in a hydroponic floating system

The floating system is an easy and profitable growing technique for the cultivation of small-sized vegetable crops. Purslane (Portulaca oleracea L.) is a spontaneous wild grass particularly diffused in the Mediterranean basin area that contain high levels of a number of nutritionally important compounds, namely vitamins, and ¿-linolenic acid. In this research, the effects of salinity (0, 2.5; 5; 7.5; 10; 12.5, 15, 17.5 and 20 dS m-1) on germination, growth and yield of purslane cultivated in a floating system by means of-1 exposure to different NaCl concentrations (2.5; 5; 7.5; 10, 12.5 and 15 dS m-1) in the nutrient solution were studied. Results indicated that seeds can germinate at very high salt conditions. Higher g-1ermination percent-a1ges were obtained between the salinity levels of 2.5 dS m-1 (59%) and 15 dS m-1 (48.5%). The growing cycle was carried out in the greenhouse in April-May 2003. The duration of the cultivation cycle was 50 days. Salinity reduced both aerial and root growth. Yield was also affected by-2salinity. The maximum yield was achieved in the lowest saline treatment (3.8 kg m -2) whereas the minimum yield was in the highest salinity concentration (2.9 kg m-2).